Characterizing the Batching Properties of Sandcrete Blocks: Case Study of Evboneka Fine Aggregates

A major factor responsible for building failures is the use of substandard materials for construction. In this regard, investigations into the quality of construction materials are highly imperative. This article examined the relationship between the number of masonry block units cast from a bag of cement and the compressive strength from samples 125mm thick at various curing age, ranging from 7 to 28 days at a fixed water-cement ratio of 0.55, mix ratios ranging from 1:6 to 1:18 at incremental steps of 2, using fine aggregates from Evboneka in Ovia North East Local Government Area of Edo State, Nigeria. Eighty four samples of 450mm by 225mm by 125mm dimensions were cast with Ordinary Portland Cement of Grade 42.5 tested to failure for each curing period. From the results obtained, it was discovered that at 28 days, the strength ranged from 0.122N/mm2 to 1.240N/mm2 corresponding to mix ratios 1:18 and 1:6 at 41.70 and 15.36 number of blocks per bag of cement respectively. All results got for all curing periods showed that Evboneka-sourced fine aggregates are unsuitable for both load and non-load bearing structural applications with respect to NIS 87: 2000 (minimum of 3.45N/mm2 and 2.5N/mm2 for load and non-load bearing respectively) and National Building Code of Nigeria, 2006 (minimum of 1.75N/mm2 for load-bearing) which imply that fine aggregates sourced from Evboneka should be batched using mixes richer in cement, below ratio 1:6 or 15.36 block units per cement bag.