Gap-Graded Versus Continuously-Graded Shrinkage-Compensating Concrete

摘要

The work presents a comparative study of expansion-shrinkage characteristics of gap-graded and continuously-graded shrinkage-compensating Type-K concretes. Type-K shrinkage-compensating cement content has been adopted as the main variable parameter. The influence of this parameter on the expansion-shrinkage characteristics is studied for 50 specimens of gap-graded and continuously-graded concretes. Specimens consisted of two types: (a) with lateral reinforcement (1.16 percent), and (b) without any reinforcement. Within the range and premises of the present investigation, it was concluded that unrestrained continuously-graded shrinkage-compensating concrete requires 37.7 percent more Type-K cement, while, with lateral restraint, it requires 39.2 percent more Type-K cement, than the equivalent gap-graded shrinkage-compensating concrete having same compressive strength and workability. Thus the investigation has shown that a significant economy can be achieved for shrinkage-compensating concretes by adopting gap grading instead of the conventional continuous grading of aggregates. (Author)