Evaluation of CDOT specifications for class H and HT crack resistant concrete.

Details

• Creators:
  Durham, Stephan A. ; Cavaliero, Robert W.
• Corporate Creators:
  University of Colorado at Denver. Department of Civil Engineering
• Corporate Contributors:
  United States. Federal Highway Administration
• Subject/TRT Terms:
  • Concrete pavements
  • Pavement maintenance
  • Cracking of concrete pavements
  • Pavement cracking
  • Cracking
  • Testing Pavements, Concrete--Colorado--Testing
  • Bridges--Colorado--Floors--Testing
• Publication/ Report Number:
  CDOT-2010-5
• Resource Type:
  Tech Report
• Geographical Coverage:
  Colorado
• Edition:
  Final.
• Corporate Publisher:
  Colorado. DTD Applied Research and Innovation Branch
• Abstract:
  This study examined the performance of concrete mixtures designed to increase cracking resistance for Colorado bridge decks. The ; current CDOT Class H and HT concrete mixtures and nine other mixtures were investigated to aid in the development of a more crack ; resistant concrete specification. A total of eleven concrete mixtures were designed, batched, and tested for their fresh and hardened ; concrete performance. Specifically, the designs differed by type of cement, w/cm, cement content, supplementary cementitious materials ; (SCMs), use of chemical admixtures, and aggregate type. Compressive strength, permeability, freeze-thaw resistance, and restrained ; shrinkage cracking were evaluated and documented in this report. Lower w/cm resulted in high early compressive strengths and rates of ; strength and strain development. Increasing the w/cm to 0.44 and Class F fly ash replacement levels up to 30% was beneficial in ; controlling strength gain. A low cement content mixture with increased w/cm and fly ash replacement proved to be beneficial. When ; SCMs were not utilized, a low cement content of 6.0 bags was beneficial. When SCMs were used, increased cement content helped to ; maintain the same properties. Type G, coarse-ground cement was beneficial to strain and strength at the higher w/cm of 0.42 and low ; cementitious materials content. At a lower w/cm of 0.38, the mixture behaved similarly to the control mixture fabricated using Type II ; cement, developing strain and strength at an average rate. ; A high dosage rate of a shrinkage reducing admixture was extremely beneficial in controlling both the development rate and ultimate ; strain of the mixture, while maintaining adequate development of ultimate strength at all ages. An average dosage rate of a set retarder ; only retarded the initial strength development slightly. After 1 day of age, the development of strength and strain was substantially ; increased. Although the concrete containing the set retarder reached higher compressive strengths more quickly than anticipated, the ; concrete did not crack in the AASHTO PP34 test and was moderately durable.
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• Format:
  PDF
• Download URL:
  https://rosap.ntl.bts.gov/view/dot/18117/dot_18117_DS1.pdf
• File Type:
  [PDF - 3.06 MB]
• Collection(s):
  US Transportation Collection
• Main Document Checksum:
  urn:sha-512:00854340d65c4d78d8017205177351fcb80cfc89bcdfb510dab9db951150eefff19ce05700486bab5b32684af83d3b946a84c450236c74421e133f69ec37ed8c