Self-compacting concrete of medium characteristic strength

The wide use of self-compacting concrete (SCC) in the precast industry versus its moderate use in the ready-mixed concrete industry, has led to the development of products within the upper-middle performance range, leaving gaps unfilled in some applications where low or medium strength is required. The aim of this paper is to demonstrate, theoretically and practically, the feasibility of developing SCC in the range of medium strength. In this study, cement kiln dust (CKD) was used as a local filler, and six mixtures with different percentages of cement replacement by CKD were investigated. Properties at fresh and hardened state were studied. The use of high percentages of CKD and different combinations of water/fines ratio allows economizing on the use of the admixture and the amount of cement required, obtaining SCC of medium strength and lower production costs.

► SCC of medium characteristic strengths result technically and economically competitive in ready-mixed concrete industry. ► A conceptual approach was developed to obtain SCC of medium strength, following the path of physical process. ► The theoretical proposal was validated with an experimental program, in which local materials were used. ► High percentages of cement kiln dust and higher water/fines ratio allows economizing on superplasticizer and cement amounts. ► SCC tested show good and very good quality of concrete coating and low and moderate chloride ions penetration.