City-wide Quality Assessment of Sandcrete Masonry Blocks Produced in Lagos, Ibadan and Abeokuta Metropolitan-cities in South-western Nigeria

Abstract

In this research work, a total of nine thousand (9,000) numbers of Sandcrete masonry blocks and another total of nine thousand (9,000) numbers of Sandcrete masonry blocks were collected as Test-samples from three hundred (300) Sandcrete block-making factories, which are randomly sited in thirty (30) rapidly developing towns/localities located within three (3) highly-populated and state-capital metropolitan-cities—i.e. ‘Lagos’, ‘Ibadan’ and ‘Abeokuta’ in South-Western Nigeria. Thus, from the cumulative total number of eighteen thousand (18,000) Sandcrete block test-samples, each of the thirty (30) numbers of ‘block test-samples’ and each of the thirty (30) numbers of ‘block test-samples’ which were collected from each of the ten (10) Block-making factories per town/locality was subjected to two (2) critical quality-evaluation tests—i.e. Compressive-strength test [using a compression-testing machine] and Water absorption coefficient test [in accordance with standard established procedures and then, the mean values were computed and adopted as the representative/characteristic data for each Block-making factory. Consequently, the obtained results/data were then comparatively analyzed using the Standards Organization of Nigeria ‘SON’standard specified (recommended) values to empirically evaluate the Block-making/production quality of each of town/locality per city and of each city. Amongst other things, the comparative analysis of the obtained results/data showed that: while all of the tested Sandcrete masonry blocks produced in Lagos city and Ibadan city are classified as substandard—having failed to meet (fulfill) the standard requirements; just of the Sandcrete masonry blocks, and as much as of the Sandcrete masonry blocks produced in Abeokuta city are classified as standard—having successfully met (satisfied) the Standard requirements—thus, making them the most ideal for construction purposes.