Use of cement sand admixtures to produce high strength soil bricks for low cost housing projects

Abstract

Housing is universally accepted as a basic human need. Demand and cost of construction materials have drastically increased with the growth of population in Sri Lanka. In order to address this issue, attention has been focused on low-cost housing materials in this study. Accordingly, this research is focused on use of cement-sand admixtures to produce high strength soil bricks. Lateritic soil and ordinary Portland cement were used for this study. Soil bricks were produced by increasing the cement compositions upto 5%, 10%, 15%, 20% of the total volume, and compacted to 33.33% and 44.44%, while applying 5kN force, and allowed for curing for 28 days. Average compressive strength of 5% cement soil bricks under above compaction ratios were 1.3MPa and 1.9MPa which is less than the standard limits of 2.8MPa stated in SLS 1382:2009, and it was 3.0MPa and 3.6MPa for 10% cement. However, the mixtures w i t h 15% and 20% cement exceeded the required strength. The wet compressive strength of said brick was 2.6MPa and it was greater than the standard limits. The findings of this study confirmed that the decrease in particle size of the soil and the increase of compaction ratios increases the compressive strength of bricks. Therefore, a soil brick made with 10% cement, compressed to 33.33% is more appropriate for the low cost housing projects.