2016 Volume 27 Pages 13-23
Against a backdrop of depleted supplies and the declining quality of natural aggregate, concrete with crushed aggregate is widely used in the construction of important concrete structures. This report introduces research on quality improvements achieved using the SEC (Sand Enveloped with Cement) method, a two-stage mixing method, for the purpose of improving segregation qualities (including bleeding) and workability, which often present issues when using concrete with crushed aggregate. The research results confirmed reductions in bleeding, as well as dramatic improvements in properties closely associated with concrete durability, including compressive strength, drying shrinkage, and water and gas permeability. It was concluded that the SEC method helps achieve uniformity of the concrete within concrete structures and effectively improves quality.
