Optimizing cementious content in concrete mixtures for required performance.

Details

• Creators:
  Taylor, Peter ; Bektas, Fatih ; Yurdakul, Ezgi ; Ceylan, Halil
• Corporate Creators:
  Iowa State University. National Concrete Pavement Technology Center
• Corporate Contributors:
  United States. Federal Highway Administration
• Subject/TRT Terms:
  Admixtures Cement Concrete Water Cement Ratio
• Resource Type:
  Tech Report
• Geographical Coverage:
  Iowa
• Corporate Publisher:
  United States. Federal Highway Administration
• Abstract:
  "This research investigated the effects of changing the cementitious content required at a given water-to-cement ratio (w/c) on workability, strength, and durability of a concrete mixture.
  
  An experimental program was conducted in which 64 concrete mixtures with w/c ranging between 0.35 and 0.50, cementitious content ranging from 400 to 700 per cubic yard (pcy), and containing four different supplementary cementitious material (SCM) combinations were tested. The fine-aggregate to total-aggregate ratio was fixed at 0.42 and the void content of combined aggregates was held constant for all the mixtures. Fresh (i.e., slump, unit weight, air content, and setting time) and hardened properties (i.e., compressive strength, chloride penetrability, and air permeability) were determined.
  
  The hypothesis behind this study is that when other parameters are kept constant, concrete properties such as strength, chloride penetration, and air permeability will not be improved significantly by increasing the cement after a minimum cement content is used.
  
  The study found that about 1.5 times more paste is required than voids between the aggregates to obtain a minimum workability. Below this value, water-reducing admixtures are of no benefit. Increasing paste thereafter increased workability. In addition, for a given w/c, increasing cementitious content does not significantly improve compressive strength once the critical minimum has been provided. The critical value is about twice the voids content of the aggregate system. Finally, for a given w/c, increasing paste content increases chloride penetrability and air permeability."
  
  
• Format:
  PDF
• Funding:
  DTFH61-06-H-00011 Work Plan 20
• Collection(s):
  US Transportation Collection
• Main Document Checksum:
  urn:sha-512:c734d5130b94ca1dbdfc4ffe22497cf2fd2900d2a244898fa8e2f05020851de0a33ae3422c9e7315866b227cfa47d8b856bf853dfcb5a9f9b2de3a11f9dce861
• Download URL:
  https://rosap.ntl.bts.gov/view/dot/23896/dot_23896_DS1.pdf
• File Type:
  [PDF - 1.82 MB ]