Characterization of Superplasticized Microsilica Concrete

Authors: Akiije I

DOI Info: N/A

ABSTRACT

Deplorable highway conditions due to poor concrete proportioning has led to the search for possible acceptable mixes for construction. Two groups of mixes, each one consisting of a normal concrete (NC) and three different types of superplasticized microsilica concretes (SMC) were investigated. The SMC process involved six concrete mixtures having partial replacement of cement with microsilica and addition of equal amount water of superplasticizer independently to the mixing water. SMC had superplasticizer content of 2% while microsilica varied from 1% to 3% of cement amount. The two groups of concretes were of aggregates-cement ratio of 3:1 as Group A and 4:1 as Group B. NC of Group A had water cement ratio of 0.45 while SMC had water cementitious material ratio of 0.325. NC Group B had water cement ratio of 0.5 while SMC had water cementitious material ratio of 0.35. I-pavers, Z-pavers, rectangular pavers and 150 mm cubes were used as experimental specimens. Hardened concretes specimens produced were examined for compressive strength at moist curing scheduled for 7, 28, 56 and 90 days. The results showed that the higher the partial replacement of cement with microsilica the higher the slump value for Group A experiment whereas Group B gave reverse of same. Z-paver had the highest compressive strength of the three types of paving blocks but lower than that of 150 mm cube. However, the cube compressive strength could not satisfactorily be the representation of pavers for flexible pavements design.

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