بازيافت زايعات گياهي در اكوپاركها و پاركهاي ملي با استفاده از روش كمپوست

پروژه كلاسي درس: آلودگي مواد زائد جامد و روش هاي كنترول آن

تهيه كننده : فروزان مصباح ايراندوست دانشجوي كارشناسي ارشد محيط زيست- آلودگي هوا

خرداد ماه سال 1381

منابع و معادن مصرف شده توسط انسان از سال 1950 تاكنون تقريبا برابر است با منابع و معادن مصرفي از شروع تاريخ تا سال 1950. علت افزايش در مصرف منابع را مي توان پيشرفت سريع تكنولوژي در پنج دهه گذشته دانست اين افزايش باعث گرديده است تا با مصرف بيشتر منابع و معادن ميزان مواد زائد و زباله ناشي از اين منابع و توليدات و مشتقات آن از افزايش چمشگيري بر خوردار باشد و عدم برخورد صحيح و با زايعات و زباله ها دنياي سلامت  انساني را  به مخاطره مي اندازد. افزايش به يك باره ميزان مواد زائد و زباله ها انسان را بر آن داشت كه به نحو مطلوبي با خطر چنين معظلي به روشهاي منطقي مبارزه نمايد. براي چنين مبارزه اي دو روش معرفي شده است، روش اول آنكه همچون گذشته به روش سنتي اقدام به ساخت مكانهاي دفن زباله نمايند و مواد زائد و زباله هاي عملا دفن شوند و روش دوم كه در دو دهه اخير بيشتر مد نظر واقع شده است استفاده از تكنولوژي جديد در بازيافت اين موا د براي استفاده مجدد از آن و عملا حركت در مسير از بين بردن زباله با توجه به بازيافت آن.

در كشورهاي مختلف پرداختن به دو موضوع فوق از درجه اهميت متفاوتي برخوردار بوده است. در آمريكا بعلت وجود مقدار بسيار زياد زمين بيشترين متد استفاده شده در دفع زباله متد دفن است. به همين دليل در مناطقي همچون ايالات هاي نودا،اتا، ويومينگ، نورس داكتوا، مونتنا و آيدوهو بيشتر از روش سنتي براي از بين بردن مواد زائد خود استفاده مي كنندعلت بارز آن هم سرمايه گذاري بسيار محدود اين ايالاتها در بازيافت كه بطور سرجمع  در سال 97 تا 98 تنها 497000  دلار جهت بازيافت زباله سرمايه گذاري نموده اند حال اينكه در ايالت واشنگتن به تنهايي اين سرمايه گذاري بالغ بر 12 ميليون دلار بوده است. چنين سرمايه گذاري جهت بازيافت 40 درصدي ميزان زباله هاي اين ايالت بوده است. اين در حالي است كه در اروپا بخصوص در كشورهاي اسكانديناوي وآلمان استفاده از تكنولوژي بازيافت را در اولويت خاص برنامه هاي اقتصادي و سرمايه گذاري كشور هاي خود قرار داده است و روش  دفن زباله در اين كشورهاي بسيار مورد مذموم و جهت جلوگيري از توسعه آن چنين كشورهايي با بكارگيري مالياتهاي سنگين براي  محل دفن زباله ها ( لندفيل ها) سعي در كنترول و كاهش آن نموده است. در كشور دانمارك هدف اصلي و سياست گذاري اصولي در مواد زائد و زباله ها، كاهش آن بوده است به نحوي كه اولويت  خاص را در جهت بوجود آوردن استراتژي جلوگيري و كاهش زباله و مواد زائد قرارداده است و سپس اولويت بعدي را به بازيافت اين زايعات و زباله ها به نحوي قرارداد كه در سال 2000 موفق شد  تا حد 50 درصد زايعات را بازيافت نمايد.

در سوئد 38 درصد زايعات و زباله ها جامد شهري سوزانده مي شود و و 32 درصد آن بازيافت و كمپوست  و نهايتا 30 درصد ما بقي دفن مي شود. سوئد در راستاي كاهش دفن زباله ها براي هر تن دفن زباله 30 دلار ماليات وضع نموده است.

در آلمان  وزارت محيط زيست در سال 1995 تخمين زده بود در ده  سال آينده با توجه به افزايش جمعيت ظرفيت مكانهاي دفن زباله تكميل  خواهد شد و عملا ديگر فضايي براي دفن آن وجود نخواهد داشت و وزارت خانه مذكور در سال 1991 قانوني را جهت توسعه سرمايه گذاري در بازيافت زباله به تصويب رساند. امروزه آشپزخانه يك شهروند آلماني داراي سطل زباله هايي است كه از هفت قسمت تشكيل و هر قسمت از رنگهاي مختلف براي جمع آوري زباله هاي مختلف مورد استفاده قرار مي گيرد و عملا فرهنگ جمع آوري  نوعهاي مختلف زباله بطور مجزا بين شهروندان آلمان بخوبي جا افتاده است.

تحقيقات بعمل آمده نشان مي دهد كه بازيافت نتنها باعث جلوگيري آلودگي محيط زيست مي شود بلكه باعث دست نخوردن منابع طبيعي و همچنين توليد انرژي بازيافت را به همراه خواهد داشت. اين نكته رانيز مي بايستي مد نظر نظر داشت كه ايجاد اشتغال و پايين آوردن هزينه هاي توليد در بخش اقتصاد بواسطه استفاده از تكنولوژي بازيافت از درجه اهميت خاصي بر خوردار است به نحوي كه بسياري از اقتصاد دان ها معتقداند كه سرمايه گذاري در بازيافت به مراتب از هزينه هاي دفن زباله كمتر است.

در سال 1996 هزينه ايجاد محل دفن زباله ( لند فيل) بين 3 تا 4 ميليون دلار در كشورهاي صنعتي هزينه در بر داشته است و مسدود كردن محل دفن و ايجاد محل دفن جديد هزينه بالاسري بالغ بر 2 ميليون دلار ديگر به هزينه هاي فوق اضافه نموده است.

در كشور هاي اروپايي در سال 1999 جهت جلوگيري از توسعه مكانهاي دفن زباله مالياتهاي آن را از 33 دلار در هر تن به 42 دلار و در سال 2000 به 60 دلار در هر تن افزايش داده است اين دولتها با بالا بردن ماليات دفن زباله دو استراتژي مهم را دنبال ميكنند اولا كاهش دفن زباله ها كه سلامت محيط زيست را به مخاطره خواهد افكند و دوم ايجاد سرمايه لازم از محل اخذ مالياتهاي فوق در سرمايه گذاري ايجاد تكنولوژي بازيافت.

اصولا بررسي موضوع و عنوان زباله و مواد زائد  خود بخود يك ديدگاه اقتصادي ايجاد مي نمايد. وقتي كارخانجات  مقدار بسيار زيادي از توليدات خود را به دلائل مختلف از رده خارج و عمدتا  بعنوان  دور ريز آن كارخانه را تشكيل مي دهد، به جهت اقتصادي بودن توليدات خود  مي بايستي براي اين محصولات بازاريابي  مجدد نمايند و يا اينكه از توليد آنها حلوگيري نمايند.  لذا در صورت عدم بازريابي مناسب براي اين قبيل توليدات بازيافت مواد شايد بعنوان راه حل مناسبي براي جبران بخشي از ضرر و زيان ها مطرح شود.

اصولا وقتي كه مجامع در مي يابند كه براي جمع آوري زباله هاي شهري  و زباله هاي تجاري هزينه هاي آنچناني بايد پرداخت كنند كه زباله ها را دفن كنند آنگاه به اين فكر مي افتند كه بجاي پرداخت اين هزينه هاي گزاف براي دفع زباله به دنبال موقعيت استراتژيكي براي بازيافت آنها خواهند بود لذا براي رسيدن به چنين استراتژي در بازيافت مواد زائد و زباله سيستمي تحت عنوان  Eco Industerial Park را مد نظر قرار داده اند.

EIP ( Eco Industerial Park)

EIP يك مجموعه از كارخانجات توليدي و خدمات تجاري است كه به دنبال جلوگيري از آلودگي محيط زيست و بهينه نمودن اقتصاد بوسيله  كاليبره كردن مديريت محيط زيست و منابع موجود همچون انرژي ، آب و مواد است. هدف EIP بهينه كردن كارآيي اقتصادي شركتهايي و كارخانجات بازيافتي است كه در اين مجموعه با ايجاد ارتباط همزيستي  متناسب، توليد يكي بعنوان خوراك ديگري مورد استفاده قرار مي گيرد.

عملا ايجاد سيستم EIP اهداف زير را دنبال مي كند.

      1.         توسعه  كارخانجات و ايجاد تجارت محلي

      2.         توسعه اشتغال زايي با ايجاد حرفه هاي مهارتي جديد

      3.         بازيافت ارزش اقتصادي مواد از بين رفته بجاي دفن آن

      4.         جدا كردن مواد دور ريختني رستورانها و محصولات كشاورزي و بازيافت آنها براي استفاده مجدد آن در كشاورزي.

      5.         تجزيه زايعات صنايع و بازيافت آن وبكارگيري آن در ايجاد انرژي

روش ايجاد   EIP

در ايجاد ساختار EIP مواد ذيل مي بايستي مد نظر واقع گردد.

      1.         ديدگاه بسيار ويژه در ايجاد چنين سيستمي

      2.         رهبريت قوي در بخش تجارت و صنعت

      3.         دسترسي به اطلاعات در مورد مواد دور ريز منابع مختلف صنعتي و شهري و غيره

      4.         لزوم وجود قوانين و شرائط همسو در جهت ايجاد چنين سيستمي

      5.         اقدام مؤثر در آماده نمودن فرهنگ عام جامعه براي كمك به ايجاد چنين سيستمي

بحث  در خصوص EIP  نيازمند يك بررسي و مطالعه فراوان در بخشهاي مختلف است و دليل آن گستردگي چنين سيستمي جهت بازيافت انواع مختلف مواد زائد و زايعات اعم از صنعتي وكشاورزي و زباله هاي شهري  و غيره است كه در اين نوشتار تنها به يك بخش كوچكي از آن كه كمپوست كردن زايعات پاركها و جنگل هاست را مورد بحث و بررسي قرار مي دهيم.

Ecopark و  Natinal Park ها

پاركهاي طبيعي و پاركهاي ملي كه در كشورهاي بزرگ همچون آمريكا از اهميت توريستي خاصي برخوردار است و بعضا ساليانه ميليون ها نفر  در اين پاركها تردد مي نمايند  لزوم يك برنامه ريزي مناسب براي حفظ محيط زيست اين پاركها  به شدت احساس مي شود.

در جهت حفظ سلامت محيط زيست اين پاركها و استفاده بهينه از زباله ها و مواد زائد آن با تعريف سيستم بازيافت محدود  زباله و زايعات پاركي سعي در استفاده بهينه از اين منابع شده است به نحوي كه در پارك ملي يلو استون ساليانه  حدودا 340 تن مواد زائد و زباله در اين پارك  بازيافت مي شود. از ديگر موارد بازيافت در اين پارك، بازيافت بيش از دو نيم ميليون پوند آب مستهلكي  است كه پس از عبور از سيستم تسويه مجددا مورد استفاده قرار ميگيرد. ايجاد سيستم گرمايش و سرمايش  ساختمانهاي اين پارك با استفاده از انرژي ايجاد شده از چوبهاي  حرس شده شاخه درختان و زايعات چوبي پاركها كه بصورت تكه هاي مناسب  جهت سوزاندن درآمده اند بعنوان خوراك كوره هاي مخصوص چنين سيستمي بكار مي رود در اين پارك از چنين منبع سوختي خود كفايي ايجاد انرژي لازم حرارتي براي گرم كردن استخرها و خشك كن هاي تعبيه شده در پارك نيز استفاده مي شود.

در اين پاركها سطل هاي مخصوص بازيافت مواد به نحوي تعبيه شده است كه عموم مردم زباله هاي مختلف و متفاوت خود را بطور مجزا در اين سطلها قرار دهند.

عملا مسئولين پاركها با استفاده از ايجاد سيستم هاي  كاربرد مواد زائد و زايعات پاركها با قراردادن استراتژي ذيل كه شامل:

بازيافت

مديريت مواد زايعات

كمپوست كردن زايعات جنگها و پاركهاي ملي

و كاهش هزينه ها

به دنبال بكارگيري  منابع مواد زائد با روشهاي فوق براي رسيدن به امكانات توليد شده بازيافتي و بكارگيري اين امكانات براي رفاه و آسايش با هدف حفظ پاكيزگي محيط زيست و كاهش هزينه ها ست. يكي از مهمترين بازيافتها در پاركهاي ملي و اكوپاركها بازيافت زايعات گياهي  به روش كمپوست مي باشد كه در اين نوشتار  به اين نوع بازيافت بيشتر پرداخته مي شود.

بازياف زايعات گياهي به روش كمپوست در پاركها :

مواد زائد گياهي درون پاركها و جنگها ميزان بسيار زيادي از زايعات را تشكيل مي دهد. اين زايعات عبارتند از برگهاي درختان، بوته هاي قطع شده، چمن هاي زده شده و ساير اوركانيك هاي گياهي موجود در پاركها و باغها و جنگلهاست. كمپوست كردن زايعات پاركها يكي از بهترين روش هاي بازيافت در مقايسه با تكنيكهاي انهدام و يا دفن كردن آنها مي باشد. كمپوست، هم به لحاظ هزينه  اي و هم به لحاظ مديريتي بسيار كم هزينه و سهل و آسان تر است. توليدات حاصله از كمپوست ميتواند بعنوان كود گياهي، لايه بالايي خاك و به عنوان مواد حفظ كننده و نگهدارنده ريشه هاي گياهي و همچنين مواد عالي بسيار مناسبي كه بعنوان مواد افزودني به خاك مي توان استفاده كرد را نام برد.

دياگرام ذيل مواد زائد ناشي از اكوپاركها و پاركهاي ملي را نسبت به ساير زايعات در آمريكا را براي سال  1996 را نشان مي دهد  

همانگونه كه در گراف مشخص شده است ميزان زايعات گياهي بعد از زايعات كاغذ در امريكا  در رتبه دوم قرار گرفته است البته ميزان اين زايعات به فاكتورهاي مختلفي از جمله تعداد درختان و بزرگي آنها بستگي و همچنين حجم و وزن اين زايعا ت در فصول مختلف متفاوت است.در سال 1996 ميزان زايعات گياهي 20 درصد كل زايعات در آمريكا بوده است.

سوزاندن برگ درختان شايد بدليل مرطوب بودن اين برگها و عدم سوخته شدن كامل آن بعنوان يك نكته  منفي  چنين روش دفع زايعات محسوب مي شود و لذا راه حل كمپوست براي بازيافت اين زايعات بعنوان بهترين روش پذيرفته شده است.برگهاي درختان از ساده ترين عناصري هستند كه براحتي قابل كمپوست شدن هستند. بيشترين ميزان برگها به لحاظ تناژي در فصل پائيز بدست مي آيد و كمپوست شدن اين برگها در روش معمول آن حدودا يكسال بطول خواهد انجاميد.

علفها و بوته هاي هرز قطع شده و ساير زايعات گياهي در اكوپاركها و پاركهاي ملي در بهار و تابستان به  بيشترين  ميزان خود ميرسند. علف ها و چمنهاي تازه بعلت دارا بودن ميزان نيتروژن بالا نياز به رسيدگي بيشتري دارند چرا كه بدليل نيتروژن بالا سريعا كمپوست مي شوند، پريود كمپوست شدن اين نوع زايعات گياهي 4 تا 6 هفته بيشتر نيست.

در پروسه كمپوست علفها و چمنها، جهت جلوگيري از ايجاد بو حداقل روزي دو بار بايد مواد كمپوست  هم زده شود و براي رسيدن به بهترين حالت كمپوست اين نوع زايعات گياهي بهترين روش مخلوط كردن اين زايعات با مقداري از زايعات برگي و ريشه اي است.

درختان كاج قطع شده كه به طور اخص بعنوان درخت كريسمس كاربري دارند و بقاي چوبي همچون شاخه هاي درختان حرس شده  داراي كربن بالايي هستند كه اين كربن ها باعث طولاني تر شدن پروسه كمپوست مي شود. موسساتي هستند كه  درختان كاج مخصوص كريسمس را پس از دور افتان جمع آوري و طي يك پروسه آنها را به تكه هاي كوچك تبديل و از آن عملا در جهت استفاده از نگهداري ريشه گياهان و همچنين بعنوان خوراك بوجود آورنده انرژي حرارتي پاركها استفاده مي شود. معمولا براي بهينه كردن كمپوست علفها و بوته ها نيز مقداري از اين تكه  درختان را نيز اضافه مي نمايند تا ضمن طولاني تر شدن زمان كمپوست نوع كمپوست بدست آمده نيز از كيفيت بالاتري برخوردار باشد.

روشهاي كمپوست در پاركها

سه روش متداول در كمپوستها وجود دارد كه عبارتند از

Turned Windrow,     Force Aeration,   In Vessel System

Turned Windrowروش

يكي از روشهاي بسيار متداول در كمپوست متداوم روش ويندرو مي باشد كه يك كوپه از زايعات كمپوستي بطور طولي كه طول آن چند صد يارد ميرسد است كه هوا دهي و مخلوط كردن آن به روش مكانيكي صورت مي گيرد.تناوب چرخش اين زايعات در اين روش  از اهميت خاصي برخوردار است. عملا تناوب چرخش تاثير بسيار زيادي در توليد كمپوست هاي با كيفيت بالا و يكنواخت در مدت زمان كمتر را سبب مي شود. كمپوستها مي توانند با اين روش در خلال مدت 3 ماه تا 2 سال توليد شوند. طول زمان توليد كمپوست به نوع زايعات گياهي و درجه حرارت محيط كمپوست و همچنين تناوب چرخش بستگي دارد.

كمپوست كردن به روش ويندرو

  
  کمپوست به روش ويندرو

روش Force Aeration

در اين روش شبكه هايي از لوله هاي پلاستيكي در زير توده هاي زايعات تعبيه شده است به نحوي كه عبور هوا از اين لوله هاي اكسيژن لازم را به مواد ميرساند اين روش گرانتر از روش  Windrow مي باشد، اين روش  بيثشتر در كمپوست كردن Sludge (لجن) يا مواد زائد غذايي كه نيازمند كنترول هوادهي و درجه حرارتي آن از حساسيت بالاتري برخوردار است استفاده مي شود.

روش In Vessel System

در اين روش ضايعات گياهي درون ظرف سيستم بسته اي قرار ميگيرد كه تجهيزات اين سيستم بسته تركيبي از هوادهي و مخلوط كردن مكانيكي  مي باشد. بكار گيري اين سيستم نوعي حفاظت از كمپوست در مقابل آب و هواي محيط اطراف و همچنين از پراكندگي بو نيز جلوگيري مي نمايد. ساخت اين سيستم گران تر از دو روش ياد شده فوق است و به نظر  مي رسد هزينه تهيه هرتن كمپوست  از مواد زائد خيس بين 40 تا 150 دلار برآورد مي شود. در اين سيستم تمامي  انواع ضایعات گياهي قابل كمپوست شدن مي باشند.

                                                                                                                                                           كمپوست به روش اين وسل سيستم

چگونگي تعيين وزن و حجم مواد زائد پاركها

وزن و حجم مواد زائد پاركها و فصول متفاوتي كه ميزان اين وزن و حجم را تعيين ميكند از اصول اوليه تعيين نوع و طراحي سيستم كمپوست مي باشد. بنابر اين وزن و حجم جهت تعيين ظرفيت و طراحي ايستگاه  توليد كمپوست بسيار حائز اهميت است. غلظت و جرم حجمي مواد زائد به ميزان رطوبت و حجم متراكم شده آن بستگي داردلذا اين ميزان با شرائط مختلف متفاوت است. براي آشنايي با بدست آوردن غلظت و جرم حجمي  اين زايعات، جدول زير بعنوان يك مرجع مي تواند مورد استفاده قرار گيرد.

جرم حجمي
 وضعيت
 زايعات
 
100
 حرس شده خشك
 تيكه چوبهاي ، شاخه ها
 
260-200
 حرس شده خشك
 برگ درختان
 
450-250
 تكيه شده پوشالي خشك
 برگ درختان
 
1100-500
 فشرده شده
 علف و چمن و بوته
 
500-350
 فله و مرطوب
 علف و چمن و بوته
 
930-350
 جمع آوري شده معمولي
 زايعات زميني پاركها
 
600-450
 تكيه شده و زايعات چوبي
 زايعات زميني پاركها
 

متد جمع آوري مواد زائد پاركها

مواد زائد و زايعات پاركهاي شهري را با استفاده از روش تجريه زباله  و يا Curbside جمع آوري كرد. روش كروبسايد  عموما روش گران قيمتي است ولي از كارايي بالايي برخوردار است. قراردادن تريلرها، كانتينر ها، كانتين هاي مجزاي مواد زائد پاركها و جنگلها  از مواردي است كه بطور موفقيت آميز مورد استفاده قرار گرفته است و  با اين روش برگها و شاخه هاي حرس شده ، علفها ي هرز و چمنها و بوته هاي قطع شده مي توانند با دقت كافي جمع آوري شوند. با توجه به گوناگوني مواد زائد روشهاي مختلفي براي جمع آوري زايعات استفاده مي شود. براي مثال برگها  را در كيسه و يا به صورت فله جمع آوري مي كنند در جمع آوري فله  مي توان از تجهيزات مختلفي براي جمع آوري برگها از روي زمين استفاده گرد. در صورت جمع آوري كيسه اي مي توان از كيسه هاي پلاستيكي، كاغذي و يا نخي استفاده كرد. جمع آوري كيسه اي  و همچنين تخليه آن از كيسه روش گران قيمتي است ليكن كيسه هايي وجود دارد كه از جنس قابل تجزيه اي مي باشد كه تنها با دادن يك برش ساده روي كيسه، زايعات را بهمراه كيسه مي توان در كمپوست استفاده كرد. استفاده از كاميونها مكنده در جمع آوري فله اي برگها از متد هاي پسنديده جمع آوري است ليكن پروسه چنين 

                                                                   جمع آوري كيسه اي                                جمع آوري با كاميون مكنده

جمع آوري به لحاظ مخلوط شدن زايعات مكيده شده توسط دستگاه و براي مجزا كردن زايعات از يكديگر از زمان طولاني تري برخوردار خواهد شد.

بطور اجمال اينكه كمپوست كردن سابق بر اين يكي از روش هاي گران دفع زايعات محسوب مي شد ليكن با افزايش هزينه هاي ساخت مكانهاي دفن كه بمراتب گرانتر مي باشد روش كمپوست بعنوان يك روش قابل رقابت با ساير روشها شناخته شده است.

هزينه تخمين زده كمپوست كردن يك فوت مكعب زابعات گياهي بين 5 تا 30 دلار براي روش ويندرو و براي گرانترين روش آن 75 تا 300 دلار در هر تن مي باشد. ايجاد ايستگاه كمپوست در مقايسه با ايجاد امكانات و ايستگاه تبديل زايعات به انرژي  و يا حتي دفن آن بمراتب ارزانتر تمام مي شود به اضافه اينكه توليد نهايي مشتق از كمپوست با قيمت مناسبي در بازار قابل فروش است كه نتنها هزينه تمام شده آنرا پوشش مي دهد بلكه سود مناسبي را نيز از محل فروش آن بهمراه خواهد داشت.

براي ايجاد كمپوست با كيفيت بالا كه براحتي در بازار قابل فروش باشد زايعات غير گياهي همچون پلاستيك، شيشه، فلز و لاستيك مي بايستي از زايعات گياهي مجزا شوند و عملا در مراحل اوليه جمع آوري اين زايعات دقت عمل بيشتري بعمل آيد. يك اصل اساسي در بازيافت به روش كمپوست درجه خلوص زايعات گياهي است كه مي بايستي عاري از هرگونه زايعات غير گياهي باشد. لذا براي پايين آوردن چنين ريسكي سيستم جمع آوري زايعات گياهي مي بايستي با دقت كافي صورت پذيرد.

منابع

Enviromental Stewardship (www.xanterra.com)

Eco industrial park project (www.sustainable.boe.gov)

Eco Park for enviromental business and explorative exhibition (www.eaue.de)

Cornell Waste Management  by Rice Hall Newyork

Getting to Zero Waste By Michel jessen  (www.toenall.org)

Hot mix asphalt plant user manual
Section 1

QUALITY MANAGEMENT SYSTEM (QMS) FOR ASPHALT PAVEMENTS

1.1 GENERAL
Section 609 of the NCDOT Standard Specifications and all applicable Project or Standard Special Provisions provide for Quality Control and Quality Assurance of asphalt pavements by use of a Quality Management System (QMS).  The basic concept for this process is that the Contractor perform adequate testing and inspection to insure a quality asphalt pavement and the Department perform adequate testing and inspection to insure that the Contractor’s results are accurate.  This system requires both the Department and the Contractor to have technicians that are competent in testing and inspection of asphalt pavements.  The general idea is for the Contractor to perform the necessary tests and inspection to insure the likelihood that all mix meets the Specifications instead of “after-the-fact” testing to see if it does meet the Specifications.  This approach gives the Contractor much more control over his total operations.  He is responsible for his product from the design of the mix to the final acceptance of the pavement.  The Department simply monitors his process to be sure that what he is doing is adequate and accurate.

The Contractor’s responsibility under the QMS process is referred to as Quality Control (QC).  The Department’s responsibility under the QMS process is referred to as Quality Assurance (QA).  The Contractor is responsible to provide competent personnel to perform his quality control and the Department is responsible to provide competent personnel to perform it’s quality assurance.  The requirements and details of certification for these personnel to perform the QC/QA work is given in Section 1.3.6 and 1.3.7 of this manual.

The requirements for the Contractor’s QC sampling and testing are contained in Section 609 of the Specifications and Section 7 of this Manual. The frequency of these activities may vary with the process and the materials.  When test results vary from the design and/or specifications, changes to the process shall be made.  The frequency of the appropriate activities shall be increased until the proper conditions have been restored.  The Department’s requirement for the QA sampling and testing is a minimum of 10% of the QC samples taken and tested by the Contractor.

The Contractor may utilize innovative equipment or techniques not addressed by the specifications or these provisions to produce or monitor the production of the mix, subject to approval by the Department's Pavement Construction Engineer.

QMS is a total process that encompasses the Contractor’s mix design, the QC testing and inspection, and the Department’s quality assurance and acceptance of the Contractor’s process and procedures.  Each of these aspects of the total process will be addressed in detail later in this manual.  While all of these are very important, the real success of this program is that the Contractor and the Department carry out every aspect of the process such that a quality asphalt pavement is the final product.

1.2 CONTRACTOR'S QUALITY CONTROL PLAN

The Contractor will not be required to submit a written quality control plan to the Department; however, the Contractor, at a minimum, shall perform all quality control activities required by the specifications as well as accepted asphalt industry quality control practices and procedures.

1.3  ASPHALT QMS TECHNICIAN QUALIFICATIONS AND CERTIFICATIONS

1.3.1 General

The technician's role is extremely vital in every road construction project, especially in asphalt construction.  He has the job of ensuring that the pavement design as described in the plans and specifications produces a strong, durable, and reliable pavement on the roadway.  The technician's job is one that demands knowledge, awareness, keen observa-tional skills, and diplomacy.  It is among the toughest jobs in the con-struction industry.
 Most road and highway construction in North Carolina is performed under contract.  One party (the Contractor) agrees to perform certain work that meets specified standards.  In return for this work, the Contractor is paid by the other contractual party (the owner) who is often a local, state or federal government agency.  The contract between Contractor and owner includes plans and specifications that must be followed during pavement construction and be met by the finished product.  Whether or not these requirements are fulfilled determines the quality level of the finished pavement and how well the pavement will serve the public.

Because asphalt pavement construction is often complex, plans and specifications are often detailed and lengthy.  Ensuring that they are followed precisely demands that the owner and the Contractor have an agent acting as their eyes and ears - an agent who is on-hand throughout the construction process.  That agent is the asphalt technician.  It is the technician's duty to see that construction operations produce the results called for by the plans and specifications.  In this capacity, both the DOT's technician and the Contractor's technician have certain areas of responsibility to identify deviations from project specifications and to see that they are corrected immediately.  In any case, neither technician has the authority to change or modify the specifications.

Knowledge is the path every technician must follow to improve his performance and capability.  Whether a technician is new to the job or an old hand, his learning never stops.  New developments that affect his job are constantly appearing.  Additionally, every technician needs to refresh his knowledge periodically and to brush up on procedures that are used infrequently.  This manual is a good source of refresher information, as well as a basic text for training the new asphalt technician.

A manual alone, however, is not enough.  It must be used in conjunc-tion with other learning tools.  The most effective learning tool is on-the-job training.  The job-site is where things are happening that a technician must know.  It is the ideal place to observe, to ask questions, to get answers.  On the job, the new technician develops inspection skills first-hand and discovers what occurs during hot-mix asphalt construction and why certain methods achieve certain results.  Combined with this course of instruction, on-the-job training provides the technician with the necessary tools to carry out his duties and responsibilities.
.
1.3.2 Purpose of Inspection and Testing

The purpose of inspecting and testing asphalt construction is to ensure the quality of the work meets project requirements and specifications.  To accomplish this, the asphalt technician must be familiar with the parts of the con-struction contract that apply to his job.

The contract is the agreement between the owner or contracting agency and the Contractor.  It states the obligations of both parties, including labor, materials, performance and payment.  While there are many documents that make up the construction contract, the technician is concerned prima-rily with the plans and specifications.  Together, plans and specifications explain requirements that the Contractor must fulfill to build a satisfac-tory pavement and get paid in full for his work.

Plans are the contract documents that show the location, physical aspects, details and dimensions of the work.  The plans include layouts, profiles, cross-sections and other details.

Specifications are the written technical directions and requirements for the work; also, the standard specifications and the special provisions complement the plans by providing instructions that are not specifically indicated on the drawings.  Specifications are the means of communication among the designer, the Contractor, and the technician.  Specifications include Standard Special Provisions and Project Special Provisions, which simply are revisions to the specifications.

1.3.3   DOT Technician's Authority

The Division Engineer or project Resident Engineer assigns the DOT’s technicians, and their authority is stated in the Standard Specifications under Duties and Authority of the Inspector (Article 105-10).  The Technician assists the Engi-neer in determining that the work done and the materials used meet contract requirements.  The Technician has the authority to reject defective materi-als and to advise the Contractor that payment will be withheld for work that is being done improperly.  The Engineer may delegate additional authority to him; however, the Technician is not authorized to make any final acceptance of the work.

1.3.4   DOT Technician's Relationship with Contractor

It is required by the Specifications that a preconstruction conference be held between the inspection and engineering personnel of the owner and the Contractor's supervisory personnel.  At such a meeting the plans and specifications are reviewed, material deliveries and construction techniques discussed, traffic control procedures agreed upon, specific project responsibilities and lines of authority defined, and any other necessary items that may have a bearing on the project are discussed.

One of the most important aspects of the technician's job is his relationship with the Contractor.  This relationship affects the management of the project.  A good personal rapport assists the Technician in resolving problems that might arise.  When dealing with the Contractor and his personnel, the Technician should be friendly, but he must be firm and impartial in making decisions.  If the Technician experiences difficulties with the Contractor, he should immediately inform the Engineer.

The Technician will assist himself, as well as the Contractor, by trying to understand the project from the Contractor's point of view.  The Technician is primarily interested in quality (how good the pavement is); the Contractor is primarily interested in quantity (how much pavement is placed in a given time).  Under no condition should the Technician permit a reduction in quality in the interests of quantity.  However, as long as
pavement quality is maintained, the Technician should assist the Contrac-tor's efforts to place hot-mix as efficiently as practical and within specifications.

The Technician has the obligation to influence the construction process so that the best possible roadway is constructed.  He cannot simply take a passive role when observing a problem.  He must be willing to help solve it.  For example, after observing a particular situation, the Technician may be able to suggest a change in procedures that could improve the quality of the work while increasing the efficiency of the operation.  Such a suggestion benefits both the Contractor and the Department of Transportation.

When offering assistance in solving problems, however, the Technician must be careful to avoid involving himself in the supervision of construc-tion.  He should avoid giving the impression that he wants to control the work, and he must never issue an order to the Contractor's workers.  Assuming supervision of the work puts the Technician in the undesirable position of judging the quality of work by means that he dictated.

1.3.5   Qualifications of QC and QA Technicians

The personal attributes required of a technician go beyond those expected of an ordinary workman.  The technician must be honest.  He must conduct himself in a fair and straightforward manner.  While under stress, he must be able to maintain his composure and make good decisions.  He must have keen common sense for making competent decisions.  He must be frank and sincere in his relationships with people and must be a skilled diplo-mat, able to handle tough situations without arousing hostility.  Above all, he must be observant and be capable of keeping good records.

A technician should have a high school education.  Some technical study, and construction experience are helpful.  As a minimum, however, the technician must be able to perform accurate mathematical calculations and should be familiar with the fundamentals of engineering equations.  It is essential that he knows how to read and understand plans, specifications and other contract documents in order to understand requirements of the work.

Although not responsible for the design of roadways, the technician should understand the basic engineering principles involved.  He should be familiar with the characteristics of materials and know the principles of material testing, including the interpretation of test results.

The technician must have specialized knowledge pertaining to his particular job.  For example, a plant technician must have a thorough working knowledge of asphalt plants, but he must also have a broad general knowledge of asphalt materials, production, and construction procedures.  Practical experience with asphalt mix production, roadway construction, and asphalt laboratory testing is a valuable asset.

If all the qualifications of a technician could be reduced to four, they would be: (1) knowledge, (2) common sense, (3) observational skills, and (4) courtesy.  The basic summary of each is presented below.

(1)  Knowledge--The technician must know about the work that he is inspecting.  He should be familiar with materials, equipment and asphalt hot-mix pavement construction procedures.  The more knowledgeable a technician is, the better prepared he is to perform his duties.

(2)  Common Sense--A good technician must have abundant common sense.  While common sense is no substitute for knowledge, it is the means of interpreting the specifications to properly enforce their intent.  Common sense grows out of knowledge, but it cannot be learned out of a book.

(3)  Observational Skills--A technician can act only on what he observes.  What is not seen is missed.  Thus, it is important not only for a technician to look carefully at everything going on around him, but also to see what he looks at.  "Seeing" in this context means thinking carefully about what the eyes observe.  Without seeing, a technician can observe an incorrect condition and not realize it.

(4) Courtesy--A major part of the technician's job is to inform others when unsatisfactory conditions exist or when the specifications are not being met.  Both parties expect valid criticism and objections from the other, yet the manner of presenting comments can often become the source of poor relations between Contractor and technician.  Experience shows that it is not what is said, so much as the way it is said that is important.  Gruff, bossy and sarcastic comments are unacceptable from any technician, even if given in answer to aggravating remarks from others.

Once Contractor-DOT relations deteriorate, the work suffers.  Since the technician's primary concern is to preserve the quality of the work, he should show common courtesy at all times, even when tempted not to do so.

Although desired qualities for prospective technicians can be listed, the bottom line is this:  To do a professional job, the technician must want to do a good job, know how to do it, and go about it in a manner that contributes favorably to the project. 

1.3.6   QMS Technician Requirements

On Quality Management System projects, all asphalt plant mix testing technicians (both Contractor & DOT) are required to be certified through the Department's current Asphalt Technician Certification Program.  On projects let under the Superpave Design procedure, all plant technicians (both Contractor and DOT) must be certified as Superpave plant technicians, and on projects let under the Marshall design procedure these technicians must be certified as Marshall plant technicians. Certified QMS Level I Plant Technicians are testing personnel and are required to be at the plant site at all times during production of material for the project. A plant operator who is a certified Asphalt Plant Technician Level I may be utilized to meet this requirement when daily production for each mix design is less than 100 tons (100 metric tons) provided the randomly scheduled increment sample as defined in Sub-article 609-5(C)2 is not within that tonnage. When performing in this capacity, the plant operator will be responsible for all quality control activities which are necessary and required. Absences of the Level I Technician, other than those for normal breaks and emergencies must be pre-approved in writing by the appropriate QA Supervisor or his designated representative(s). Any extended absence of the Technician that has not been approved will result in immediate suspension of production by the Engineer.  All mix produced during an unexcused absence of the Level I technician will be accepted in accordance with Article 105-3 of the Specifications.  The Contractor is also required to have readily available (on-call) a QMS Level II Plant Technician responsible for making process control adjustments and solving mix problems.  He must be located such as to be able to respond to all plant mix problems in a timely manner.  The Department will have at least one certified QMS Level II Plant Technician on its' Quality Assurance (QA) team as well as several Level I Technicians.  Either a QC or QA Level II Technician may also function as a Level I Technician, in which case he/she would fulfill the requirements for both the Level I and II technicians.

All Roadway Technicians are required to be certified through the Department’s current certification program. The Contractor is required to have at least one certified roadway technician on the project at all times during normal laydown operations. A certified DOT Roadway Technician will also be on-site at all times during production.  The Contractor’s technician(s) must meet the same requirements as DOT personnel and will be certified by the same certification program.

The Department's Certification Program for QMS plant and roadway technicians is managed by the Construction Unit's Pavement Construction Section.  This section will maintain a listing of all plant and roadway QMS personnel certified by NCDOT.  This listing will be maintained in an internal computer database (HiCams).
The Pavement Construction Section may be contacted at 919-733-3579 for further instructions on how to access this information.  This listing may be used to verify certification of personnel working on QMS Superpave projects.

It is required that both DOT and Contractor Nuclear Density Gauge Operators be certified through the Department’s current QMS Nuclear Density Technician’s Program.  The Contractor’s nuclear gauge operator is required to be on the project at all times when nuclear density testing is required.  The DOT gauge operator will only be on the project as necessary to perform quality assurance testing.

The Department’s Certification Program for QMS Nuclear Gauge Technicians is managed by the Soils Engineer of the DOT M&T Unit.  The Soils Engineer will maintain a listing of all certified QMS Nuclear Density Technicians and may be contacted at 919-733-3242 for verification of these.  This listing will also be maintained in a computer database.

The QMS Specification requires that the Contractor design his own asphalt mixes.  He may do so by use of his own personnel or by hiring an approved agency to do it for him.  Whichever the case, any technician performing mix designs for use on QMS specification projects must be certified through the Department’s current mix design certification program.  This certification program is managed by the Asphalt Design Engineer of the DOT M&T Unit.  The Asphalt Design Engineer may be contacted at 919-733-3563 for verification of a technician’s mix design certification.
 An organizational chart, including names, telephone numbers, and current certification numbers of all the Contractor's personnel responsible for the quality control program shall be posted in the Contractor's laboratory while the asphalt paving work is in progress.

1.3.7    NCDOT Asphalt Technician Certification Program

1.    General

The certification of asphalt technicians is a program by which it can be reasonably assured that both the DOT's quality assurance personnel and the Contractor's quality control personnel are knowledgeable and qualified to perform the required sampling, testing and inspection of asphalt mixtures and pavements.  Certification will also include a general knowledge of the techniques and equipment used in the construction of asphalt pavements, including asphalt plant operations, placement operations and compaction operations.  Under the NCDOT program, a technician may be certified in either mix design techniques, plant operations, roadway operations, nuclear density gauge operations, or all of these.  Certification in either area will include some overlap into the other area.  For example, a certification in plant operations will include a basic knowledge and understanding of roadway procedures, etc.  This is required since it can be readily seen that proficiency in one area requires some general knowledge of the overall operation.

The certification program will be operated on a continuing basis.  There will be classes and examinations scheduled throughout each year. In addition, there will be a continuous “on-the-job” training program for Level I plant & roadway technicians.  The Pavement Construction Engineer will provide applications for and maintain a master training schedule of all related classes.

Both the applications and schedule may be downloaded from the Pavement Construction Section's web site located at the following web address:

www.doh.dot.state.nc.us/operations/dp_chief_eng/constructionunit/paveconst/

Enrollment procedures for these training classes are contained at the end of this Section.  All certifications will generally be effective for four years beginning from the date of passing the certification test and then must be renewed.  Details for renewal of certifications are covered later in this section.
 

2.   Types of Certifications

Listed next are the different types of certifications related to asphalt pavements and a basic job description for each.  As mentioned previously, a technician may be certified as any one or more of these, or possibly all of these. As noted in the prerequisites listed later, some certifications require a lower level certification before advancement to the next level of certification.
A. QMS Superpave Certification

1.QMS Level I Superpave Plant Technician - A Technician trained and competent in testing and inspection of Superpave asphalt mix at the plant.

2.QMS Level II Superpave Plant Technician - A Technician trained and competent in making Superpave mix adjustments and solving Superpave asphalt mix problems.

3.QMS Mix Sampling Technician -   A Technician trained and competent in sampling of Superpave asphalt mix problems.

4.QMS Roadway Technician -   A Technician trained and competent in roadway laydown, compaction, and density procedures.

5.QMS Nuclear Gauge Operator -   A Technician trained and competent in the use of a nuclear density gauge in accordance with the QMS specification.

6.Superpave Mix Design Technician -  A Technician trained and competent in the area of Superpave asphalt mix design procedures.

B.  QMS Superpave Certification Requirements
The basic requirements for these five types of certifications are listed as follows:

1. QMS Level I Plant Technician

    1. Prerequisite(s):  Introduction to Asphalt Pavements Course w / Passing Exam.
    2.  Training:
                   Step 1 :Level I Plant Technician OJT Program (See Section 11 of this manual for the QMS-3 checklist with instructions)
                   Step 2: Level I Plant Technician Class w/ Passing Exam
    3. Experience Requirement: Minimum 20 working days per OJT Program

2. QMS Level II Plant Technician

        A.  CURRENT LEVEL I PLANT TECHNICIAN
              1.  Prerequisite(s): Minimum of 1 year ‘s Experience as Level I Plant Technician
              2.  Training: Step 1:  Approved Superpave Mix Design Course w/ Passing Exam
                                   Step 2:  Level II Plant Technician Class w/ Passing Exam
              3.  Experience Requirement: One (1) year as Level I Technician or Equivalent
                                                          Experience as Determined by Pavement Const.Engineer.

3. QMS Mix Sampling Technician

              1. Prerequisite(s):  None.
              2.  Training:    Step 1: Attend 1 day training class
                                    Step 2: Pass written exam and complete hands-on Training

4. QMS Roadway Technician

              1. Prerequisite(s):  Introduction to Asphalt Pavements Course w / Passing Exam.
              2.  Training:    Step 1: Roadway Technician OJT Program (See Section 11 of this manual for the QMS-5 checklist with instructions)
                                    Step 2: Roadway Technician Class w/ Passing Exam
              3.  Experience Requirement:  Minimum 20 working days per OJT Program
5. QMS Nuclear Gauge Operator

     A. NCDOT TECHNICIANS
          1. Prerequisite(s): a) NCDOT Nuclear Safety Training Course
                                b) NCDOT "field certified" nuclear gauge operator prior to class attendance.
          2. Training:  QMS Nuclear Density Technician Course with Passing Exam.
          3. Experience Requirement: "Hands-on" QMS training after completion of class.
     B.   NON - NCDOT TECHNICIANS
          1. Prerequisite(s): Nuclear Safety Training Course
          2. Training:  QMS Nuclear Density Technician Course with Passing Exam.
          3. Experience Requirement: "Hands-on" training after completion of class.

6. Superpave Mix Design Technician

          1. Prerequisite(s):  (1) QMS Level I or II Superpave Technician OR
                                       (2) Completion of the Level I Superpave OJT Program and Enrollment in a Level I Superpave Class OR
                                       (3) Equivalent Experience as Determined by the NCDOT Asphalt Design Engineer.
          2. Training:     Step 1:  Approved Superpave Mix Design Course with passing exam
                                Step 2:  Checkoff on Aggregate Concensus Property Tests
                                            (Contact Local QA Supervisor for Details)
                                Step 3:  NCDOT Mix Design Certification Class including Passing Exam.

A certificate will be issued for each type certification.  Initial certification will generally be effective for four (4) years beginning from the date of passing the appropriate written exam, except that a Mix Sampling Technician Certification has no expiration date.  Failure of an exam will require the person to re-attend the regular class and pass the exam to become certified / re-certified.  Upon two consecutive failures of the exam, the person will be required to perform the OJT (On-the-Job-Training) prior to re-attending the full class and taking the exam, unless otherwise approved by the Pavement Construction Engineer. Upon satisfactory completion of all requirements, the technician will be issued a certificate.

It should be noted that there is no certification for the Introduction to Asphalt Pavements Course.  This is a very basic asphalt course designed to provide general knowledge of both plant and roadway operations to personnel with little or no experience.  It is a prerequisite for several other certifications; therefore, a “completion” certificate will be issued to verify satisfactory completion.  A written exam will be given at the end of the course and will be used to judge satisfactory completion.
 

3. Renewal Certification

A technician is required to renew his certification prior to the expiration of the current certificate.  If a Techician’s certificaton expires, he will not be permitted to perform the duties of this expired QMS Superpave Certification until renewal occurs.  He will also be required to complete all initial requirements as outlined above.  Requirements for renewal of certifications are as follows.

Level I & II Plant Technicians :  Attend the regular Level I or Level II plant technician class including passing a written exam.

Roadway Technicians :    Attend the regular one day roadway technician class including passing a written exam .

 Nuclear Gauge Operators :       Attend the regular nuclear density gauge operators class, including passing a written exam, and a "hands-on" checkoff.

 Mix Design Technicians : Attend the regular mix design certification class including passing a written exam.

 4. Loss of Certification by Revocation

Technicians, whether NCDOT or Industry personnel, are subject to loss of certification by revocation.  The primary reason for the loss of a certification by this means would be the falsifying of test results, records and/or reports.  Other reasons that might lead to loss of certification include insubordination, gross negligence and apparent incompetence on the part of the technician.  Any reported occurrence of the willful violation, misuse or abuse of this certification will be investigated by the NCDOT Pavement Construction Engineer and he will advise the State Roadway Construction Engineer of any findings and recommendations.  Final revocation of the certification, when deemed appropriate, will be made in writing by the State Construction Engineer to the affected technician, with notification to all other applicable parties.  The length of revocation shall also be determined by the State Construction Engineer.

1.3.8    NCDOT Asphalt Technician Certification - Enrollment Procedures

The Department requires all students to enroll in the appropriate class(es) prior to attendance of that class(es).  Below are the guidelines for class enrollment into the training classes.  It is extremely important that these guidelines be followed in order to ensure correct enrollment data.

NCDOT QMS Asphalt Class Enrollment Guidelines

 1. Students will only be enrolled by submission of application, applicable fee, and all
    other required documents.  Class space or slots will not be held or reserved.

 2. Only mailed applications are accepted for non NCDOT enrollees.  Mailed or HICAMS applications are acceptable for NCDOT personnel.  No faxed applications accepted.
 
 3. Non NCDOT applications must be mailed to the address on the bottom of the application form.
     All NCDOT enrollments must be forwarded to and verified by the person in the division responsible for asphalt class enrollments.

 4. Required verification of prerequisites must be marked on and/or attached to the application form.  Applicants must meet all prerequisites at time of application submittal.

 5.  Non NCDOT agencies must attach a non-refundable check(s) to the application.  NCDOT Divisions/Units funds will be drafted to cover their fees.

 6.   When registering multiple students, one check per class.  One check per student preferred.

 7. Registration form & check (if applicable) must be received no later than 7 calendar days prior to    class start date.  Applications/check will be returned if not received within this time frame.

 8. Confirmation notice will be sent to all enrolled students.  NCDOT personnel registered thru HICAMS are not enrolled until approved by agency conducting the class.  Persons should
      not attend class without having received a confirmation notice.  If confirmation notice is not received within 5 days of class start date, contact Pavement Const. Section at 919-733-3579.

 9. Substitution, deletion or transfer of registered students must occur no later than 5 business days prior to class start date. If substitution or transfer of a registered student(s) is allowed, a new confirmation notice will be
     furnished.

 10.  Absent students Will Not be transferred to another class.  If enrollment is desired for a later class, the enrollment process must be repeated for that student, including payment of the fee.

 11.  Applications received after a class is full will be returned.  Maximum class size depends on the classroom size, except for Level II Class which will be limited to 30 students.

 12. Level I and II Classes are subject to cancellation if not more than 10 students are registered within 7 calendar days of class start date.

 13. Introduction & Roadway Classes are subject to cancellation if not more than 20 students are registered within 7 calendar days of class start date.

MATERIALS USED IN ASPHALT PAVING

2.1 INTRODUCTION
The modern use of asphalt for road and street construction began in the late 1800s, and grew rapidly with the emerging automobile industry.  Since that time, asphalt technology has made giant strides such that today the equipment and techniques used to build asphalt pavement structures are highly sophisticated.

One rule that has remained constant throughout asphalt's long history in construction is that an asphalt pavement is only as good as the materials and workmanship that go into it.  No amount of sophisticated equipment can make up for use of poor quality materials, poor sampling and testing techniques or poor construction practices.

In 1987, the Strategic Highway Research Program (SHRP) began developing a new system for specifying asphalt materials.  The final product of the SHRP asphalt research program is a new system referred to as “Superpave” which stands for Superior Performing Asphalt Pavements. Superpave is an an improved system for specifying component materials, asphalt mixture design and analysis, and pavement performance prediction.  The system includes test equipment, test methods, aggregate and binder specifications and mix criteria based on traffic loading, environmental considerations and other factors. This section of the manual is a discussion of materials used in quality asphalt construction - what they are, how they behave, and how to tell whether or not particular materials are suitable for a paving project.  It is basic information that technicians must have in order to make sound decisions and ensure a quality product is produced.

2.2 GENERAL DESCRIPTION OF ASPHALT PAVING MATERIALS / PAVEMENTS

 Asphalt pavements are composed of three basic components - asphalt binder, mineral aggregate and air voids.  Aggregates are generally classified into two groups - coarse and fine, and normally constitutes 90 to 96 percent by weight of the total mixture.  Asphalt binders are classified by various grading systems and normally constitutes 4 to 10 percent of the total mixture.  Another very important but often overlooked component of an asphalt mix is air voids.  In this section of this manual, only asphalt binder, aggregates and other additives are discussed.  Air voids and the role it has in asphalt mixtures and pavement performance will be discussed in later sections of this manual.

 There are many different types of asphalts and many different types of aggregates.  Consequently, it is possible to make different kinds of asphalt pavements.  Among the most common types of asphalt pavements are:

 *  Asphalt concrete (dense-graded hot mix asphalt);
 *  Open-graded asphalt friction course;
 *  Ultra-Thin Bonded Wearing Course;
 *  Asphalt Surface Treatments;
 *  Emulsified asphalt mixes (cold mixes);
 *  Permeable Asphalt Drainage Course
 *  Others, SMA, In-Place Recycled Mixes (both hot and cold)

This manual primarily addresses asphalt concrete (sometimes referred to as “hot mix asphalt” or simply “HMA”).  HMA is a paving material that consists of asphalt binder and mineral aggregate with appropriate air voids.  The asphalt binder, either an asphalt cement or a modified asphalt cement, acts as a binding agent to glue aggregate particles into a dense mass and to waterproof the mixture.  When bound together, the mineral aggregate acts as a stone framework to impart strength and toughness to the system.  The performance of the mixture is affected both by the properties of the individual components and the combined reaction in the system.

2.3 TECHNICIAN RESPONSIBILITIES

The Contractor’s Quality Control technicians and the DOT’s Quality Assurance technicians are responsible for the way asphalt and aggregate materials are handled, stored, sampled, mixed, hauled, placed, and compacted.  They have responsibilities to check such things as material sources, grades, types, temperatures, and moisture contents.  Both must also be fully capable of reviewing  and interpreting mix design data, laboratory test results and specifications, when necessary, as well as being able to perform sampling and testing.

The technician will be unable to perform his job without a working knowledge of the materials from which an asphalt concrete pavement is made, particularly material characteristics and their role in pavement performance.  He must also understand how improper handling of materials can adversely affect their properties and ultimately, their behavior in the finished pavement.  Having such information will give him the confidence to make proper day-to-day decisions and will eliminate the role of guesswork in the job, ensuring that good quality control is maintained.

Materials inspection and control demands accurate and thorough documentation.  Facts, figures, dates, names, locations and conditions are important elements in daily record-keeping.  Experience has taught us over the years that a scrap of information that seems unimportant when recorded can later turn out to be the very piece of information needed to analyze a serious problem.

2.4 ASPHALT MATERIALS

2.4.1 Refining Crude Petroleum

 Asphalt is a constituent of petroleum.  Most crude petroleums contain some asphalt, and sometimes crude oil may be almost entirely asphalt.  There are some crude oils, however, that contain no asphalt.

 Crude petroleum from oil wells is separated into its constituents or fractions in a refinery.  Principally, this separation is accomplished by distillation. After separation, the constituents are further refined or processed into products meeting specific requirements.  Thus it is that asphalt, paraffin, gasoline, lubricating oil, and other highly useful products are the output of an oil refinery, depending on the nature of the crude oil being processed (See Fig. 2-1).

 Because asphalt is the base or heavy constituent of crude oil, it does not evaporate or boil off when crude oil is distilled.  Accordingly, asphalt is obtained as a residue or residual product, and is valuable and essential for a great variety of engineering and architectural uses.  Practically all asphalt used in the United States is produced by modern oil refineries and is called petroleum asphalt.

 Asphalt is also sometimes referred to as a bituminous material because it contains bitumen, which is a hydrocarbon material soluble in carbon disulfide (CS2).  Tar obtained from the destructive distillation of soft coal also contains bitumen.  Consequently, both petroleum asphalt and coal tar are jointly referred to as asphaltic materials.  However, petroleum asphalt should not be confused with coal tar because their properties are significantly different.  Petroleum asphalt is composed almost entirely of bitumen, whereas in coal tar the bitumen content is relatively low.  In view of these differences, it is imperative that coal-tar products and petroleum asphalts be considered and treated as entirely separate entities.

 Petroleum asphalt for use in pavements is usually called paving asphalt, or asphalt binder to distinguish it from asphalt made for non-paving uses, such as roofing and industrial purposes.

2.4.2 Classification and Grading of Paving Asphalts

Paving asphalts are classified into three general types: (1) Asphalt Binders, (2) Cutback Asphalts and (3) Emulsified Asphalts.  Cutback asphalts and emulsified asphalts are frequently referred to as liquid asphalts.  It should be noted that at this time North Carolina Specifications do not allow for any use of cutback asphalts primarily due to environmental concerns.

Included in the Standard Specifications and Special Provisions are the specific requirements for the various grades and types of asphalt materials.  Table 2-1, 2-2, and 2-3 included in this manual summarizes the various grades and typical applications of asphaltic materials used in pavement construction by the NCDOT.  However, the technician should always review the project special provisions to determine if there are any additional grades or specific requirements which must be utilized.

Until recently asphalt binders used in North Carolina were graded based on asphalt viscosity.  In the viscosity system, the poise was the standard unit of measurement for absolute viscosity.  AC-20 was the grade in standard hot mix asphalt pavements in North Carolina.  Softer grades were sometimes used in recycled mixes to achieve a combined viscosity of the old asphalt and new asphalt binder which was equivalent to an AC-20.

In 1997 NCDOT began using the SUPERPAVE asphalt “”binder” specifications. These specifications were a major result of the SHRP research program which began in 1987.  The SUPERPAVE “binder” specifications are based on tests which measure physical properties of the asphalt “binder” that can be related directly to field performance by engineering principles.  The tests are conducted at temperatures encountered by in-service pavements. These “binder” specifications have now been adopted by AASHTO and are referenced under AASHTO M 320.

The new system for specifying asphalt binders is unique in that it is a performance based specification.  It specifies binders on the basis of the climate and in-place pavement temperatures at which the binder is expected to serve.  Physical property requirements remain the same, but the temperature at which the binder must attain the properties changes.  For example, the high temperature, unaged binder stiffness (G*/sin ?) is required to be at least 1.00 kPa.  But this requirement must be achieved at higher temperatures if the binder is expected to serve in a hot climate.

Performance graded (PG) binders are designated with grades such as PG 64-22.  The first number, 64, is often called the “high temperature grade.”  This means that the binder would possess adequate physical properties to perform satisfactorily at least up to 64ºC (147ºF).  This would be the high pavement temperature corresponding to the climate in which the binder is actually expected to satisfactorily serve.  Likewise, the second number, -22,  is often called the “low temperature grade” and means that the binder would possess adequate physical properties in pavements to perform satisfactorily at least down to -22ºC (-8ºF).

Additional consideration in selecting the grade to be used is given to the time of loading (vehicle speed on open highway, city streets, intersections, etc.), the magnitude of loads (heavy trucks), and at what level the material is within the pavement structure. Table 2-1 shows the current binder grades in Superpave Specifications (AASHTO M 320). Under SUPERPAVE specifications, the binder grade used in standard hot mix asphalt pavements in North Carolina is Performance Grade 64-22 (PG 64-22). Other grades are required under certain conditions, such as heavy traffic and in recycled mixes.

2.4.3 Asphalt Binder

Asphalt binder at normal atmospheric (ambient) temperatures is a black, sticky, semi-solid, highly viscous material.  Because asphalt binder is sticky, it adheres to aggregate particles and can be used to cement or bind the aggregate in an asphalt concrete mixture.  Asphalt binder is an excellent waterproofing material and is unaffected by most acids, alkalies, and salts.  It is called a thermoplastic material because it softens as it is heated and hardens as it is cooled.  This unique combination of characteristics and properties is a fundamental reason why asphalt is an important paving material.

Paving asphalt binder must be made fluid (liquified) for handling and use during construction operations, such as pumping through pipes, transporting in tanks, spraying through nozzles and mixing with aggregate. During the heating process the asphalt binder temperature must not exceed the manufacturers recommended temperature. If the asphalt binder is overheated, a process known as oxidation will occur. Oxidation causes the asphalt to become more brittle, leading to the term oxidative, or age, hardening.  Oxidation occurs more rapidly at higher temperatures.  A considerable amount of hardening occurs during HMA production, when the asphalt binder is heated to facilitate mixing and compaction.  When pavement construction operations are finished, the asphalt binder cools and reverts to its normal semi-solid condition and functions as the cementing and waterproofing agent that makes the pavement stable and durable.
Asphalt binder can be made temporarily fluid (liquified) for construction operations in two ways:

1   By melting with indirect heat: After construction operations, the hot liquid asphalt binder cools and returns from a fluid to a normal, semi-solid condition.

2   By emulsifying the asphalt with water: While asphalt and water ordinarily do not mix, they can be made to mix by churning asphalt in a colloid mill with water and a small amount of emulsifying agent.  The resulting product, called emulsified asphalt, is a fluid and can be handled and sprayed at relatively low temperatures.  After application, the water and asphalt separate.  The asphalt particles coalesce into a continous film that bonds the aggregate particles as the water evaporates.  When the water and asphalt separate, it is said that the emulsion breaks or sets and the asphalt residue remains.

2.4.4 Emulsified Asphalts

 As previously mentioned, heating is one way to liquefy asphalt; however, there are other ways to liquefy asphalt for construction applications.  One method is to emulsify the asphalt  in water.  Asphalt liquefied by this method is known as emulsified asphalt.  With emulsified asphalt, the basic idea is that the water will escape by absorption and evaporation, leaving the asphalt binder to do its job.

 The petroleum asphalt manufacturing flow chart (Pg. 2-4 Printed version of  2004 HMA/QMS Manual) has been extended to show the flow for making liquid asphalt materials.  It is important to note that asphalt binder is the base material that is liquified by emulsifying.

An asphalt emulsion consists of three basic ingredients: asphalt, water, and an emulsifying agent.  On some occasions the emulsifying agent may contain a stabilizer.  In the emulsification process, the asphalt binder is mechanically separated into minute globules and dispersed in water treated with a small amount of emulsifying agent.  The machine used in this process is a colloid mill.  The asphalt globules are extremely small, mostly in the colloidal size range (0.001 – 0.005 in.).

The object is to make a dispersion of the asphalt binder in water, stable enough for pumping, prolonged storage, and mixing.  Furthermore, the emulsion should break down quickly after contact with aggregate in a mixer, or after spraying on the roadbed.  Upon curing, the residual asphalt retains all of the adhesive, durability, and water-resistant properties of the asphalt binder from which it was produced.

By proper selection of an emulsifying agent and other manufacturing controls, emulsified asphalts can be produced in several types and grades.  By choice of emulsifying agent, the emulsified asphalt can be anionic (asphalt globules electro-negatively charged) or cationic (asphalt globules are electro-positively charged) or nonionic (asphalt globules are neutrally charged).  In practice, the first two types are ordinarily used in roadway construction and maintenance activities.  The letter “C” in front of the emulsion type denotes cationic.  The absence of the “C” denotes anionic or nonionic.  For example, RS-1 is anionic or nonionic and CRS-1 is cationic.

Because particles having a like electrostatic charge repel each other, the asphalt globules are kept apart until the emulsion is deposited on the surface of the aggregate particles.  At this point, the asphalt globules coalesce (join together) through neutralization of the electrostatic charges or water evaporation.  Coalescence of the asphalt globules occurs in rapid and medium-setting grades.  When this coalescence takes place, it is referred to as "breaking" or "setting".

Emulsions are further classified on the basis of how quickly the asphalt will coalesce; i.e., revert to asphalt binder.  The terms RS, MS, and SS have been adopted to simplify and standardize this classification.  They are relative terms only and mean rapid-setting (RS), medium-setting (MS), and slow-setting (SS).  The tendency to coalesce is closely related to the mixing of an emulsion.  An RS emulsion has little or no ability to mix with an aggregate, an MS emulsion is expected to mix with coarse but not fine aggregate, and an SS emulsion is designed to mix with fine aggregate.

Additional grades of high-float medium-setting anionic emulsions, designated HFMS, have been added to standard ASTM specifications.  These grades are used primarily in cold and hot plant mixes, coarse aggregate seal coats, road mixes, and tack coats.  High float emulsions have a specific quality that permits a thicker film coating without danger of runoff.

A quick-set type of emulsion (QS) has been developed for slurry seals.  Its use is rapidly increasing as the unique quick-setting property solves one of the major problems associated with the use of slurry seals.

2.4.5 Characteristics of Asphalt Binders

(A) Asphalt’s properties are temperature susceptible – asphalt is stiffer at colder temperatures.
That is why almost every asphalt binder and mixture test must be accompanied by a specified test temperature.  Without specifying a test temperature, the test result cannot be effectively interpreted.  For the same reason, asphalt binder behavior is also dependent on time of loading - asphalt is stiffer under a shorter loading time.  The dependence of asphalt binder behavior on temperature and load duration means that these two factors can be used interchangeably.  That is, a slow loading rate can be simulated by high temperatures and fast loading rate can be simulated by low temperatures.

(B) Asphalt binder is a viscoelastic material because it simultaneously displays both viscous and
elastic characteristics. At high temperatures (e.g., > 100°C), asphalt binder acts almost entirely as a viscous fluid, displaying the consistency of a lubricant such as motor oil.  At very low temperatures (e.g., <0°C), asphalt binder behaves mostly like an elastic solid, rebounding to its original shape when loaded and unloaded.  At the intermediate temperatures found in most pavement systems, asphalt binder has characteristics of both a viscous fluid and an elastic solid.

(C) Because asphalt is organic, it reacts with oxygen from the environment. Oxidation changes the structure and composition of the asphalt molecules.  Oxidation causes the asphalt to become more brittle, leading to the term oxidative, or age, hardening.  Oxidation occurs more rapidly at higher temperatures.  A considerable amount of hardening occurs during HMA production, when the asphalt binder is heated to facilitate mixing and compaction.  That is also why oxidation is more of a concern when the asphalt binder is used in a hot, desert climate.

The characteristics of asphalt binder under varying temperatures, rates of loading, and stages of aging determine its ability to perform as a binder in the pavement system.  The tests and specifications used to measure and control these characteristics in the Superpave system are discussed in Performance Graded Asphalt Binder Specification and Testing, Superpave Series No. 1 (SP-1), The Asphalt Institute.

2.4.6. Testing Properties of Asphalts

 A key feature in the Superpave system is that physical properties are measured on binders that have been laboratory aged to simulate their aged condition in a real pavement.  Some binder physical property measurements are performed on unaged binder.  Physical properties are also measured on binders that have been aged in the rolling thin film oven (RTFO) to simulate oxidative hardening that occurs during hot mixing and placing.  A pressure aging vessel (PAV) is used to laboratory age binder to simulate the severe aging that occurs after the binder has served many years in a pavement.

 Binder physical properties are measured using four devices:

dynamic shear rheometer  - controls stiffness at high temperatures
rotational viscometer  - assures binder can be pumped at 135° C
bending beam rheometer  - controls stiffness at low temperatures, and
direct tension tester  - controls resistance to low temperature cracking
 Various tests are used for determining and measuring the properties of an asphalt binder.  The ASTM and AASHTO references that describe in detail the equipment and procedures required to conduct these tests are available from a number of sources.  These tests are normally conducted by the asphalt supplier or the Materials and Tests Laboratory in Raleigh.  The specifications require that the Contractor furnish a certified delivery ticket for all asphalt materials to be used on a project (See Article 1020-1 of the Standard Specifications - Must have Adobe Acrobat Reader to open).
2.4.7 Specific Gravity of Asphalt Binder

Specific gravity is the ratio of the weight of any volume of a material to the weight of an equal volume of water, both at a specified temperature.  As an example, an aggregate with a specific gravity of 2.653 weighs 2.653 times as much as water.  Asphalt binder has a specific gravity of approximately 1.030 at 60° F (15.6° C).

The specific gravity of an asphalt binder is not normally indicated in the job specifications.  Nonetheless, knowing the specific gravity of the asphalt binder being used is important for two reasons. Asphalt binder expands when heated and contracts when cooled.  This means that the volume of a given amount of asphalt binder will be greater at higher temperatures than at lower ones.  Specific gravity measurements provide a means for making temperature-volume corrections, which are discussed later.

Specific gravity is usually determined by the pycnometer method (AASHTO T 228).  Because specific gravity varies with the expansion and contraction of asphalt binder at different temperatures, results are normally expressed in terms of Sp. Gr. (Specific Gravity) at a given temperature for both the material and the water used in the test.  (Example: Sp. Gr. 1.023 at 60°/60°F (15.6°/15.6° C) means that the specific gravity of the asphalt binder tested is 1.023 when both the asphalt binder and the water are at 60°F (15.6° C).

2.4.8 Asphalt Additives

(A) Silicone:  Silicone is used in asphalt because of its foam suppressing capabilities and also because it helps prevent the tearing and pulling of an asphalt mix behind the paving machine.  Section 620-2 of the Standard Specifications requires that silicone is to be added to asphalt binder used in all surface course mixtures, including open-graded asphalt friction courses.  The silicone is added at the rate of 1 ounce per 2000-2500 gallons (4 ml per    1000-1250 liters) of asphalt binder and may be added either at the asphalt plant or at the supplier's terminal when so noted on the delivery ticket. The silicone should be adequately circulated throughout the asphalt binder storage tank prior to use. The brand used must have been previously approved by the Department.  A listing of approved sources of silicone may be obtained through the M&T Lab in Raleigh, N.C.

(B) Anti-Strip Additive: Heat stable liquid chemical or hydrated lime anti-strip additives are required to be incorporated into asphalt mixes in an effort to prevent the separation of the asphalt from the aggregate particles (stripping).  Chemical anti-strip additives are blended with the asphalt binder prior to introduction of the binder into the mix. Hydrated lime is blended with the aggregate prior to the aggregate entering the drier.

All mixes including recycled mixes require either chemical or  lime anti-strip additive or a combination of both.  The technician should always refer to the JMF to determine the type, rate required and the brand specified.  The Contractor may use a different brand or grade, provided the proper TSR testing has been performed with satisfactory results prior to its use.  If a different rate is required, a new JMF must be obtained by the Contractor.

2.4.9 Asphalt Binder Storage

The asphalt binder storage capacity at the plant must be sufficient to allow uniform plant operation.  Where more than one grade of asphalt binder is required for a project, at least one tank will be needed for each grade or the tank must be completely emptied before a different grade is added.  Different grades must not be mixed.

Asphalt contents of storage tanks must be capable of being measured so that the amount of materials remaining in the tank can be determined at any time.  This is necessary in order to determine the amount of an additive to be added, when required.  They also must be heated to keep the asphalt fluid enough to move through the delivery and return lines; however, the maximum storage temperature should not exceed the supplier’s recommendation.  Heating is done either electrically or by circulating steam or hot oil through coils in the tank.  Regardless of the heating method used, an open flame must never come in direct contact with the tank or contents.  Where circulating hot oil is used, the oil level in the reservoir of the heating unit should be checked frequently.  A drop in the level could indicate leakage of the hot oil into the tank, leakage which results in contamination of the asphalt.  All transfer lines, pumps and weigh buckets also must have heating coils or jackets so that the asphalt will remain fluid enough to pump.  One or more thermometers must be placed in the asphalt feed line to ensure control of the asphalt temperature, as it is being introduced into the mixer or drum.  The asphalt tanks must be equipped with a circulation system capable of uniformly dispersing and mixing additives throughout the total quantity of asphalt binder in the tank.

Adequate pumps must be furnished so that asphalt binder can be unloaded from tankers and still continue to operate the plant.  A sampling valve or a spigot must be installed in the circulating system or tank to allow sampling of the asphalt.  When sampling from the circulating system, exercise extreme care, as pressure in the lines may cause the hot asphalt to splatter.

Safety:   Asphalt foaming can be a safety hazard, and specifications usually require that asphalt not foam at temperatures up to 350°F (175°C).   In addition, asphalt binder, if heated to a high enough temperature, will flash in the presence of a spark or open flame.  The temperature at which this occurs is well above the temperatures normally used in paving operations. However, to be sure there is an adequate margin of safety, the flash point of the asphalt should be known. The Minimum Flash Point temperature specified for all performance graded asphalts is 446°F (230°C).

2.4.10 Delivery and Acceptance of Asphalt Materials

Obtain Performance graded asphalt binder (PGAB) only from sources participating in the Department’s Quality Control/Quality Assurance (QC/QA) program.  The PGAB QC/QA program is designed to give Producers or Suppliers more responsibility for controlling the quality of material they produce and to utilize the QC information they provide in the acceptance process by the Department.  It requires Producers or suppliers to perform QC sampling, testing, and recordkeeping on materials they ship for use by the Department.  Also, it requires the Department to perform QA sampling, testing, and recordkeeping to confirm the performance of the Producer’s quality control plan set forth in the QC/QA program.

NCDOT specifications (Article 1020-1) require that asphalt materials used in asphalt pavement construction be tested and certified as meeting all applicable specification requirements (AASHTO M 320).  This certification for acceptance purposes is furnished with each delivered load of material, subject to certain conditions outlined in the specifications.

This Article of the specifications also requires that all asphalt transport tankers, rail, and truck tankers must have a sampling valve in accordance with Asphalt Institute Publication MS-18, Sampling Asphalt Products for Specification Compliance and AASHTO T 40 or a comparable device acceptable to the Engineer.  A picture of a typical sampling device is shown in the Figure below. (Pg. 2-10 Printed version of  2004 HMA/QMS Manual)

The sample must be taken from the sampling device on the transport tanker. Sample containers must  be new and are available from the M & T Laboratory.  Glass containers should not be used.  The sample container should not be washed, rinsed out, or wiped off with oily cloths.  The top of the container must fit securely.  In obtaining a sample from the sampling valve, approximately 1 gallon (4 liters) of the asphalt material should be drawn from the valve and discarded for sampling purposes.  The container should then be filled from the valve and the lid securely fastened to the container.  Samples shall not be transferred from one container to another.  The sample should then be forwarded to the Materials and Tests Unit with the appropriate sample identification cards.

This Article also outlines the information that is to be shown on load delivery tickets for all asphalt  materials.  Also included is an example statement of certification forms which must be included on the delivery ticket.  The Contractor must furnish a ticket from the supplier which includes a statement of certification of the grade and amount of asphalt material, including a statement relative to the brand, grade, and quanity or rate of anti-strip additive added to the material. In addition, a separate statement of certification that the tanker was clean and free of contaminating material is required from the transporter on the ticket.  Each certification shall be signed by an authorized representative of the supplier or transporter.  These certifications may be either stamped, written, or printed on the delivery ticket, or may be attached to the delivery ticket.  Failure to include or sign the certifications by either the supplier or transporter will be cause to withhold use of the material until a sample can be taken and tested, except where an alternative testing and invoicing procedure has been preapproved by the Engineer.

It will not be necessary to fill out Materials Received Reports (MRRs) for liquid asphalt (asphalt binder, emulsions).  All liquid asphalt materials will be accepted by certification in accordance with Section 1020-1 of the Standard Specifications and the following procedures.

When a shipment of asphalt binder is received at an asphalt plant, the Contractor’s plant personnel will send a copy of the bill of lading to the QA Supervisor.  The QA Supervisor will attach the bill of lading to the appropriate QC-1 report from that plant and maintain same in a separate file for that plant.  When a shipment of emulsified or  asphalt is recieved at the asphalt plant or on a project, a copy of the bill of lading will be sent to the QA Supervisor who will attach it to the appropriate QC-1 report from that plant and maintain same in a separate file for that plant.

M&T Unit representatives will take verification samples from the asphalt terminals which will be logged in and tested at the M&T central facility with results entered into a Liquid Asphalt Database.

If a sample fails but the failure is considered by the Chemical Testing Engineer to be immaterial, the terminal will be notified of the test results and allowed to continue shipping, provided corrective action is taken.  Samples will continue to be taken at the normal frequency.

If a sample fails and the failure is considered by the Chemical Testing Engineer to be significant, the terminal will be notified of the results and they will be instructed to discontinue shipments and take corrective action.  M&T will resample and retest the material at the terminal.  Any materials from this batch in a Contractor’s storage tank will be evaluated for acceptability.

In the case of a significant material failure, the Chemical Testing Engineer will send a failure notification form to all QA Supervisors.  The QA Supervisors will review the bills of lading in their files to determine if they have recieved any material from that batch.  If so, they will notify the appropriate Resident Engineers.   They will then review the appropriate QC records for any possible related test deviations.  The failure notification form will include an investigation section to be filled out by the QA Supervisor.  They should include information concerning test deviations and any actions they took concerning or involving the Resident Engineers on this form and attach it to the appropriate bill of lading and QC-1 report in their file and send a copy to the Chemical Testing Engineer.

Resident Engineers will not be receiving direct notification of failures from the Chemical Testing Engineer because there is no way he can determine who should receive the notifications.  By sending these notifications to the QA Supervisors, a relatively small number of forms can be sent out and the appropriate Resident Engineers will be notified by the QA Supervisors.

All actions taken by the Chemical Testing Engineer, QA Supervisors and Resident Engineers will be noted in the database summary.