Permeation characteristics of self compacting concrete made with partially substitution of natural aggregates with rounded lightweight aggregates

This study presents transport properties of self-compacting concretes (SCCs) in which natural aggregates had been partially replaced with lightweight fine (LWFA) and coarse aggregate (LWCA). Lightweight aggregates were manufactured through the cold bonding pelletization of 90% fly ash and 10% portland cement in a tilted pan at room temperature. A total of 17 SCCs with a water/binder ratio of 0.32 were produced at a fixed slump flow of 720 ± 20 mm by adjusting the amount of High-Range-Water-Reducing-Admixture (HRWRA) used. The transport properties were investigated via water sorptivity, water permeability, rapid chloride ion permeability, and gas permeability. Mechanical properties of SCCs were determined in terms of compressive strength, splitting tensile strength, and structural efficiency. It was found that with increasing volume of LWFA and/or LWCA, the hardened properties reduced regardless of testing age. Moreover, in spite of lower compressive strength, SCCs with LWFA had better performance in the case of durability related properties compared to the SCCs with LWCA.