Use of lightweight aggregates in pervious concrete

In this study, the use of lightweight aggregate (LWA) for making lightweight pervious concrete (LWPC) was presented. Diatomite (DA) and pumice (PA) were used as natural LWAs in pervious concretes. Three cement paste contents of 15%, 20%, and 25% by volume were used. The results were compared to those of LWPC containing recycled LWA from autoclaved aerated concrete (RA). The results indicated that the use of DA, PA, and RA as coarse aggregates in pervious concrete could reduce the density and thermal conductivity about 3–4 times compared with pervious concrete containing natural aggregate. The densities were 558–775 kg/m3 which were lower than 800 kg/m3 and suited for use as insulating concrete. The 28-day compressive strengths of LWPCs ranged from 2.47 to 5.99 MPa. The increase in cement paste content improved the mechanical properties of LWPCs. LWPC containing DA showed higher mechanical properties and a lower thermal conductivity than those of RA and PA. However PA exhibited higher water permeability.