Track: Construction Management

Abstract

Quality assurance measurement of a Sandcrete hollow block of Ado –Ekiti environs was evaluated. The township was zoned into five Zones; where four block industries were randomly selected per zone. A total of two hundred blocks were sampled from twenty block producing industries within the five zones. The study began with the digitization of the Ekiti state map, tests such as Bulk density, Absorption test, Compressive strength, Abrasion test and Impact test were carried out on the sampled blocks. Compressive strength results from the sampled blocks varied between 1.03   and 0.63N/mm², 0.60 and 0.30N/mm², 0.50 and 0.28N/mm², 1.16 and 0.73N/mm², 1.63 and 1.45 N/mm for Zones 1-5 and sample 1-4 respectively. Water absorption test result varied between 13.2% and 15.4%, and 13 and 16.5, 14% and 15.8%, 13.6% and 16.4 ,09 and 13.5% for zone 1-5 and sample 1-4, respectively. The results showed that as the strength increases, the absorption values also decrease. The analysis showed that the abrasion results varied between 40 and 65%, 40 and 75%, 48 and 95%, 40 and 88%, 30 and 46% for zone 1-5 and sample 1-4 respectively. Impact test also varied between 50 and 85%, 45 and 94%, 55 and 96%, 47 and 93% ,35 and 46 for zone 1-5 and sample 1-4 respectively. The results indicated that, from all the zones evaluated, only zone 5 which comprises of sample 1, 2, 3 are within the range specified, while zones 1, 2, 3 and 4 were not found within stipulated range of 1: 8.  It can be inferred that the blocks are not fit to be used for construction purposes. The use of sub-standard mix design should be discouraged among the block manufacturer within the study area.

Keywords: Abrasion, Compressive strength, Density, Sandcrete, Quality assurance, Zon