Hardened concrete properties

Abstract

Concrete made with coarse recycled concrete aggregate and supplementary cementitious materials must display technical properties similar to or in an acceptable range of deviation as compared to the existing conventional concrete. This enables reliable adoption of coarse RCA and SCMs as an alternative concrete constituents in practice. In the previous chapter, we have discussed the effect of SCMs on fresh properties of recycled aggregate concrete. This chapter discusses the hardened concrete properties of concrete comprising of coarse RCA and challenges associated with it. Then the synergistic effects of SCMs and coarse RCA in concrete are explored. The mechanical properties focused here include compressive strength, tensile strength, and modulus of elasticity. The roles of SCMs discussed in this chapter are limited to the widely available fly ash, slag, and silica fume. Introduction of SCMs also has an influence on hardened concrete properties, and the degree depends on percentage of replacement, physical properties like fineness, chemical and mineralogical composition, chemical reactivity, and curing age and conditions. In this chapter, let us discuss first, the mechanical properties of concrete comprising of coarse RCA and then the effect of SCMs on coarse RCA-based concrete, specifically focusing on the influence of fly ash on 100% coarse RCA-based concrete.