Effect of Cavity Volume on the Properties of Sandcrete Blocks

Abstract

Although sandcrete blocks are the most used walling material in Nigeria, their structural and physical performance is greatly impacted by differences in block shape, especially cavity volume and web thickness. This study investigates the effect of internal cavity volume on the properties of two-cell hollow sandcrete blocks. A cement–sand mix ratio of 1:6 and a water–cement ratio of 0.7 were used to create 450 × 225 × 225 mm hollow Sandcrete blocks with three cavity volume configurations: 187.5 × 175 mm× 450mm, 173 × 190 mm× 450mm, and 180 × 210 mm× 450mm, which corresponded to typical web thicknesses of 25 mm, 35 mm, and 15 mm, respectively. These blocks were then cured by the water spraying method for a maximum of 28 days. Key properties like compressive strength, density, and water absorption of the produced samples were investigated at different curing ages of 3–28 days. The results of the investigations show that, while water absorption decreases in proportion to rising web thickness and decreasing cavity volume, compressive strength and density increase. It was also discovered that sandcrete blocks with 35 mm web thickness and cavity volume of 173 mm×190 mmc × 450mm gave the best performance for both physical and structural properties. While sandcrete blocks with a 25 mm web thickness showed medium performance and the ones with a 15 mm web thickness gave the least performance. This study also recommended sandcrete blocks with a 15 mm web thickness for non-load-bearing applications due to their significant water absorption and poor strength. And sandcrete blocks with a 35 mm web thickness for heavy-duty applications due to superior density and strength. These findings offer regulatory bodies and block manufacturers useful advice in improving the quality, dependability, and structural integrity of sandcrete blocks in Nigeria.