Use of Rice husk ash as binding material in concrete for building construction in Uganda.

Abstract

Concretes is the most widely used construction material in civil engineering industry because of its high structural strength, stability and malleability. The concrete industry is constantly looking for supplementary cementitious material with the objective of reducing the solid waste disposal problem. Rice husk ash (RHA), and quarry sand (QS) are among the solid wastes generated by industry. Thus the utilization of pozzolanic material of RHA as supplementary binding material can reduce consumption and dependency on cement. Rice husk ash are used as supplementary cementing materials to improve the properties of cement concrete. The present study is done to develop quality concrete by partially replacement cement with Rice Husk Ash. The aim of study is to compare the strength characterises of concrete which as achieved by concrete mixtures. The work done in this study shows the effects on the behaviour of concrete produced from cement with combination of RHA at different proportions on the mechanical properties of concrete such as compressive strength. The replacement of cement were done at four levels is 0%, 15%, 30 and 40% with Rice husk ash and the test on fresh concrete such as Slump test was done for workability of RHA concrete percentages of 0%,15% ,30% and 40% samples which increased when the amount of RHA from 0%,15%,and 30% in the sample were increasing. RHA have finer particles which have higher surface area compared to cement particle. RHA particles filled into the spaces between the cement grains resulted in stabilizing and increase the cohesiveness of the concrete but adversely affecting the workability. The tests on hardened concrete were destructive in nature which includes compressive test on cube for size (150 x 150 x 150 mm) at 7, 14 and 28 days. The result so obtained showed that it is possible to achieve saving in cement if replacement is done. The study proves to be beneficial in building construction of Uganda for light concrete construction, also will use wastage released from rice mills in order to reduce economy as this materials is easily available. The waste material from industries is in bulk amount, as lesser amount of these used as supplementary cementing materials.

Keyword: Rice Rush Ash, Aggregates, cement.