COMPARING THE SPECIFIC GRAVITY AND WATER ABSORPTION RATE OF MECHANICALLY AND LOCALLY CRUSHED AGGREGATES

Abstract

The need for assessing construction materials is becoming a priority within the construction industry. This trend is necessitated by the high diminishing rate of construction materials, pressing demand on existing quarries, rising cost of aggregates and failures of civil structure all over the country. This research is aimed at assessing the suitability of hand crushed aggregates for use in construction as compared to the old tradition of mechanically crushed aggregates. A one-sample t-Test was carried out to test for the significant difference in the means in comparison to the standard guidelines. From findings of the t-Test conducted to test the hypothesis, there was a significant difference in the specific gravity of hand crushed (HC) aggregates (p = 0.001) for sample sites X, Y and Z. Furthermore, there was also a significant difference in the water absorption of mechanically crushed (MC) and hand crushed (HC) aggregates for sample site Z (p = 0.001 and p= 0.025). However, there was no significant difference in the specific gravity of MC for sample sites X, Y and Z with p values of 0.107, 0.539 and 0.188, respectively. Although some of the results shows conformity to the stipulated building standards of an average specific gravity 2.7 and average water absorption rate of 0.6%, it is still imperative to reassess their suitability before use in constructions. These aggregates cost less and widely used within the study area, hence becomes imperative to evaluate their suitability before use in any construction project.