Experimental investigations on mechanical properties of lightweight pervious concrete using pumice and microstructure aspects

Abstract

This study introduces a novel construction material, pumice-based Lightweight Pervious Concrete (LPC), which combines the benefits of lightweight aggregates, high porosity, and sustainability. Pumice, a naturally occurring volcanic rock, offers low density, high porosity, and pozzolanic properties that enhance the performance of pervious concrete. The study explores the mechanical, hydraulic, and durability characteristics of LPC by analyzing its density, void ratio, permeability, and microstructure. Various mix designs for pervious concrete were tested, categorizing them into two groups: conventional coarse aggregate and pumice. Wet density values for lightweight mixes (LW) ranged from 1440–1480 kg/m³, with dry densities from 1410–1465 kg/m³, significantly lower than Conventional Concrete (CC) mixes, which had wet densities of 2110–2190 kg/m³ and dry densities of 2090–2170 kg/m³. The void content in LW mixes was 22.2–23.87%, higher than the 19.21–19.87% of CC mixes, promoting permeability and groundwater recharge. Permeability tests demonstrated superior infiltration rates in LW mixes, with values up to 20.12 × 103 mm/hr, highlighting their efficacy in stormwater management. Despite lower compressive strength (2.47– 5.99 MPa), LPC exhibited satisfactory performance in lightweight applications. Microstructural analysis revealed pumice’s rough, porous texture, enhancing the C-S-H gel bond while contributing to higher porosity.