Experimental study on strength and durability of lightweight aggregate concrete containing silica fume

Abstract

In this study, the mechanical property and durability performance of high strength lightweight aggregate concrete (LWAC) with silica fume for 91days were presented. LWACs were designed to have the design compressive strength of 60MPa at 28days and the oven-dry density below 1900kg/m3. Nine mixtures with three aggregate types and silica fume replacement ratio of 0%, 3.5% and 7.0% by cement weight were prepared. The splitting tensile strength, the compressive strength and the modulus of elasticity tests were conducted at 7days, 28days, 56days and 91days. The chloride penetration resistance tests were done at 28days, 56days and 91days. The chloride diffusion coefficient based on the measurement of chloride penetration depth was also measured at 7days, 14days, 28days, 56days and 91days. The rapid freeze-thaw cycling tests were conducted and the relative dynamic modulus was evaluated up to 300 cycles. The results indicate that the durability against chemical deterioration for LWAC incorporated to silica fume depends on the compositions of hardened cement pastes in concretes, while the durability against physical attack depends on the types of aggregates.