Assessment of mechanical properties of fibrous mortar and interlocking soil stabilised block (ISSB) for low-cost masonry housing

Walls of Interlocking Stabilised Soil Blocks (ISSBs) have been considered in low-cost houses around the world especially in developing countries. These were reported to be very weak in resisting the lateral load (e.g. wind or earthquake) without special considerations. In this paper, mechanical properties (compressive strength, elastic modulus, pre/post crack energy absorbed and toughness index) of ISSBs with three configurations and seven combinations of plain and fibrous mortar cubes are experimentally evaluated. Sisal fibre and rice straw (2% and 5%, by cement mass) were considered for fibrous mortar. Empirical equations were developed to predict elastic modulus. It was found that ISSBs had reasonable strength to be considered for masonry. The failure load and toughness index of 2% sisal fibre samples was improved by 10% and 16%, respectively, whereas 2.21 times enhancement was found in elastic modulus. Thus, 2% sisal fibre in plaster (i.e. reinforced coating) would likely improve the lateral resistance of interlocked masonry walling.