Dimensional Compliance and Compressive Strength of Sandcrete Hollow Blocks Produced in Minna Metropolis

Abstract

The study was carried out to investigate the level of dimensional compliance of commercially produced sandcrete blocks in Minna metropolis and also determine the compressive strength of collected block samples. One hundred and sixty (160), nine (9) inch hollow sandcrete block samples were collected from ten sandcrete block producing companies. Fine aggregate samples were collected from the hollow sandcrete block companies along with the hollow sandcrete blocks. Sieve analysis was carried out on the soil samples. Density, water absorption and dimension of the collected Sandcrete block samples were determined. Compressive strength at 7 and 14 days curing age was also determined. Results indicate that the fine aggregates used were not suitable for block making as the coefficient of uniformity of soil samples range from 0.71 – 1.89 while the coefficient of curvature lie within 2.57 to 4.80 which do not conform to standard. None of the Sandcrete block production company met the required standard dimension as specified by Nigeria Industrial standard (NIS). Test results also revealed that the water abortion capacity of all collected block samples were below 12% maximum recommended by NIS except for block industry M which recorded 12.08%. The density was between 1.59 g/cm3 – 5.05 g/cm3, greater than 1.5g/cm3 specified by NIS. The average compressive strength was between 0.21N/mm2 - 1.11N/mm2 at 14 days curing age which was less than 3.45 N/mm2 specified by NIS. It was recommended that block producing industries should be enforced by the standard organization of Nigeria to follow the recommended standard dimensions by carrying out routine check.