Perlite is a natural glassy volcanic rock used in construction applications requiring improved lightweight, thermal, and acoustic properties. During processing of raw perlite (i.e., cutting and fractioning to different sizes), large amounts of powders are collected and stored as waste materials. This paper evaluates the effect of waste perlite (WP) powders on durability and long-term transport properties of self-consolidating concrete (SCC). Different mixtures prepared with 580 kg/m³ powder using various combinations of WP, limestone filler (LF), metakaolin (MK), and silica fume (SF) are tested over 2-years period. Test results showed that WP confers particular benefits to the SCC compressive strength and its evolution over time, particularly when used in combination with MK and SF. Water permeability, carbonation, and chloride ion migration curtailed when WP concentration reached 220 and 260 kg/m³. In contrast, the resistance against freeze/thaw remarkably improved, given the pozzolanic reactions and porous nature of such powders that accommodated the disruptive expansive stresses resulting from frost attack.

The use of recycled concrete aggregate (RCA) in structural applications considerably increased. The main objective of this paper is to assess the effect of parent concrete (PC) quality on RCA properties including concrete durability and bond to steel reinforcement. Four RCA types are considered; three were sourced from 13, 42, and 62-MPa compressive strength (f’_c) normal-density PC, while the fourth type was derived from lightweight PC. Test results showed that the PC quality has direct influence on the transfer of stresses and ultimate bond strengths to embedded rebars. The incorporation of styrene-butadiene rubber (SBR) latexes was found efficient to mitigate the drop in concrete mechanical properties including f’_c, splitting tensile strength, electrical resistivity, and ultimate bond strength to embedded steel. The experimental data are compared to the design bond strengths specified in international codes such as ACI 318-17, European Code EC-2, and fib Model Code MC2010.