Title: Shrinkage and Cracking of High-Strength Concrete and Flowing Concrete at Early Ages
Author(s): K. Yokoyama, S. Hiraishi, Y. Kasai, and K. Kishitani
Publication: Symposium Paper
Appears on pages(s): 243-258
Keywords: admixtures; air-entraining agents; cracking (fracturing); crack propagation; flowability; high-strength concretes; shrinkage; water-reducing agents; General
Paper addresses shrinkage and cracking at early ages of highly flowable flowing concrete with a special admixture (unit amount of water of 185 kg/m 3) and of normal high-strength, viscous concrete with high-range AE water-reducing agents (unit amount of water of 170 kg/m 3) under constant air flow. Results are as follows: 1) shrinkage at early ages of flowing concrete and normal high-strength concrete increased with a decrease in water-cement ratio. Shrinkage of normal high-strength concrete varied according to the admixture composition; 2) cracking of both flowing concrete and normal high-strength concrete within a restricting steel frame initiated at an earlier age and became significant with decreasing water-cement ratio. Time and amount of crack initiation of normal high-strength concrete varied according to admixture composition.