Proportional Examination of Pf Mechanical Composition of Concrete Produced with Washed and Unwashed Gravel

Abstract

Concrete is a very important material in the Nigerian construction industry as over 90% of her storey buildings are made from reinforced concrete. Local gravel is being increasingly used as coarse aggregate in place of the more expensive crushed granite in the production of concrete in parts of the country where it is found. Hence, this study aims at comparing the mechanical properties of concrete produced with washed and unwashed gravel to identify the most suitable aggregate for concrete. The use of two types of course aggregates for different works is examined in this study. Typical strength concrete is being made from various aggregates and their impact on various characteristics to the subsequent concrete. Compressive strength is the most vital property of concrete. In this paper, two forms of coarse aggregates washed gravel and unwashed gravel were utilized. Sharp sand is the fine aggregate. Initial laboratory examination was carried out to establish the appropriateness of utilizing the aggregates for construction purpose. Particle size distribution (sieve analysis) and slump test were investigated. Mix ratio (1:2:4 & 1:1.5:3) was used for this work and mix structures were analyzed by absolute weight technique. A total of 25 cubes (150×150×150mm) were cast to permit the compressive strength to be observed at 7, 14 and 21 days. Test results revealed that concrete produced from unwashed gravel has better workability than washed gravel. Higher compressive strength at all periods was observed with concrete produced from washed gravel aggregate. Compressive strength patterns were suggested as a result of age at curing.