Durability of self-consolidating concrete containing natural waste perlite powders.

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/m 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/m. 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.