Improving Compressive strength of Lightweight Aggregate Concrete

Abstract

This work aims to improve the strength of Lightweight Aggregate Concrete (LWAC) developed in Egypt using available local materials. The Crushed Sand Brick (CSB) was used with (50, 60, and 70 percent) replacement ratios of crushed dolomite by volume in two options, once without surface coating another time after coating its surface with cement mortar before mixing. It is recommended to use uncoated CSB with a replacement ratio of 60 percent which provided optimum compressive strength/density ratio. Expanded Polystyrene (EP) was cut manually and used with of 60 % replacement ratio of crushed dolomite by volume by study the effect of type of Lightweight Aggregate (LWA) on properties and strength of LWAC, finally Expanded Polystyrene Granules (EPG) with particle size less than 4.75 mm was used as 60% replacement of sand by volume. Cement content was increased from 350 Kg/m3 to 450 Kg/m3, Silica Fume (SF) was added with different doses (10, 20, and 30) % of cement by weight, and High Range Water Reducer (HRWR) was used with different doses (2, 3, and 4) % of binder materials by weight to improve compressive strength and properties of LWAC. The type of LWA was found to be the most effective factor on the strength of LWAC.