Self-consolidating characteristics of concrete composites including rounded fine and coarse fly ash lightweight aggregates

The objective of this paper is to characterize fresh properties of self compacting concretes produced with lightweight fine and coarse aggregates (LWFA and LWCA). Lightweight aggregates were produced by cold bonding pelletization of 90% fly ash and 10% Portland cement by weight in a tilted revolving pan at ambient temperature. Thereafter, a total of seventeen self compacting lightweight aggregate concretes (SCLCs) were designed with a water-to-binder (w/b) ratio of 0.32. The workability of SCLCs was quantitatively evaluated by slump flow time and diameter, V-funnel flow time, and L-box height ratio. Moreover, compressive strength of hardened SCLCs was measured at 28 and 90 days. It was found that all of the SCLCs have good deformability, passing ability, and resistance to segregation. Increasing replacement level for LWFA and/or LWCA simultaneously decreased density and increased the flowability. However, it was observed that LWCA was more useful than LWFA to obtain the same workability of SCLCs. The compressive strength of SCLC with full replacement by LWFA and LWCA was found to be 43 MPa at 28 days.