Assessment of equivalent substrate stiffness and mechanical properties of sustainable alkali-activated concrete containing recycled concrete aggregate

The effects of using recycled concrete aggregate (RCA) as coarse on the equivalent substrate stiffness and mechanical properties sustainable alkali-activated were investigated in this paper. High-calcium fly ash (HFA) commercial silica fume (SF) used precursors for producing high-calcium (AAHFAC). Sodium hydroxide (SH) sodium silicate (SS) solutions alkaline activator with constant SS/SH ratio 1.0 liquid-binder (L/B) 0.50. natural (NCA) study was crushed limestone replaced RCA at rates 0%, 20%, 40%, 60%, 80%, 100% by volume. setting time, compressive strength, elastic modulus, Poisson’s ratio, bond strength obtained pull-out tests AAHFAC Portland cement (NC) investigated. Experimental results showed that use to replace NCA resulted reducing time concrete. Also, without SF shorter than NC mixes all replacement level. had a positive effect binder; however, they declined mixes. Therefore, binder is an excellent alternative since it allows substitution resource components while somehow low CO2 emissions.