CDOT  WMA  Project  and  Specifica7ons  Summary

2011  Rocky  Mountain  Asphalt  Conference  and  Equipment  Show

CDOT  2007  WMA  Project  Summary

• Project  Loca9on:I-‐70,  70  miles  west  of  DenverMountain  terrain  –  elev.  8,800’  to  11,100’

CDOT  WMA  Project  Summary• Traffic30,000  AADT,  10%  trucks,  4.85M  ESALS  (10-‐yr.)  

• Extreme  winter  condi9ons  (truck  chain  area)

Winter  2007/8  Stats:

-‐  Snowed  65  of  76  days      between  12/1  &  2/14

-‐    128  chain-‐days        total  for  2007/8

Advera-‐WMA

Sasobit

Evotherm  injected  into  AC  feed  line  here

Evotherm

Three-‐Year  Evalua9on  and  ReportNCAT Report 10-05

Three-Year Evaluation of the Colorado Department of Transportation’s Warm-Mix Asphalt Experimental Feature on I-70 in Silverthorne, Colorado

Final Report

By

Tim AschenbrenerBill SchiebelRandy West

Sponsored by: Colorado Department of Transportation

CONCLUSIONS:

“…  A`er  three  years  of  field  evalua9ons  in  a  loca9on  with  a  harsh  winter  climate,  the  performance  of  the  WMA  test  sec9ons  was  comparable  to  the  HMA  control  sec9ons  in  regards  to  rudng,  cracking,  and  raveling.    The  field  performance  was  excellent.“

CDOT/CAPA  Task  Force

• Process  for  WMA  Approval  and  Use

• Specs  allow  either  HMA  or  Approved  WMA

• Colorado  Procedure  59Standard  Prac*ce  forContractor  Non-‐Standard  Asphalt  Mix  Approval

-‐  requirements  for  submigal,  review  and  pos9ng  of      approved  non-‐standard  mixtures      (including  WMA  technologies  and  contractors)

Colorado  Procedure  59

REFERENCED  DOCUMENTS  CDOT  Procedural  Direc*ve  1401.1     Product  Evalua7on  and  Experimental  Features  Colorado  Procedures  52     Contractor  Asphalt  Mix  Design  Approval  Procedures  AASHTO  Procedure  R35  Appendix     Special  Mixture  Design  Considera*ons  and  Methods  for  

Warm  Mix  Asphalt  (WMA)

Colorado  Procedure  59  

WMA  approval  required  for  WMA  Technology  and  Contractor

WMA  mixes  must  conform  to  CDOT  Superpave  Specifica9ons

WMA  Mix  Design  Criteria

  Aggregate  absorp9on  1.3%  or  less  -‐  can  use  HMA  mix  design  without  addi9ves  

  Aggregate  absorp9on  greater  than  1.3%  -‐  AASHTO  R35  WMA  Mix  Design  

WMA  mix  and  binder  project  acceptance  per  exis9ng  CDOT  HMA  procedures

Colorado  Procedure  59SUBMITTAL  REQUIREMENTS  -‐  Electronic  Submigals  Required

WMA  Technology  

Summary  of  the  technology   Process  controls

Addi9ve  types  and  quan99es   Addi9ve  influence  on  mix

Equipment  &  plant  requirements " Benefits MSDS  for  addi9ves       Product  history  

Project  History  with  data       Research  data

Approvals  from  other  agencies   Design  Considera9ons

Produc9on  Considera9ons  (volumetrics)

Technology  Supplier  Contacts

Colorado  Procedure  59SUBMITTAL  REQUIREMENTS  con9nued

WMA  Contractor  

Contractor  WMA  Experience,  if  any      

Contacts  for  past  project  owners

Contractor  Contacts

Design  Considera9ons Produc9on  Considera9ons

  ~  plant  configura9on  and  control  

    ~  an9cipated  field  volumetric  impacts  for  ini9al  approval  

    ~  contractor-‐recommended  field  volumetric  adjustment  

         from  lab  results  for  specific  mixes  during  construc9on

Colorado  Procedure  59

• Review  and  approval    ideally  outside  the  construc9on  season  

• Approved  WMA  technologies  and  contractors  posted  to  CDOT  Website  

• Only  approved  technologies  and  contractors  allowed  to  supply  WMA  

• WMA  use  is  the  contractor’s  op9on  –  paid  for  under  current  HMA  bid  items

Colorado  Procedure  59

• Copies  of  CP-‐59  Available

Bill  Schiebel,  CDOT  Region  1  Materials  Engineer4670  North  Holly  Street,  Unit  BDenver,  CO  80216Phone:    303-‐398-‐6801email:    bill.schiebel@dot.state.co.us

• Ques9ons  

mailto:bill.schiebel@dot.state.co.usmailto:bill.schiebel@dot.state.co.us