Concrete Production And Quality Control In Building Construction Industry Of Ethiopia

Concrete is a construction material produced from three main ingredientsrnnamely, cement, mineral aggregates and water. The production process goesrnthrough various phases. Batching, mixing, transporting, placing compacting,rnfinishing and curing are the main ones. In order to get quality concreternproduct, which satisfies both the strength and durability requirement, greatrncare has to be given for concreting work starting from ingredient selection. Therningredient selected has to fulfill the requirement stated on standards. Everyrnproduction process should follow the proper scientific procedures to get therndesired quality concrete products. For this, quality control plays a significantrnrole.rnQuality control is all the measures that are taken during material selection,rnconcrete production processes and on finished concrete products to ensure therncompliance of works with the specification.rnConcrete as a major building material, which is useful for the construction ofrnthe structural part, and as a non-factory product, which is susceptible tornvariation, proper control is utmost important in ensuring the desired qualityrnproduct. Therefore, concrete quality affects the overall quality of buildings to arnhigher extent. But in Ethiopia there hasn’t been any study made on this arearnyet.rnConsidering this, investigations focusing on concrete production and its qualityrnare undertaken in the year 2005 on forty three building construction projectsrnfound in various parts of Ethiopia namely, Addis Ababa, Nazreth Debrezeith,rnJimma, Awassa and BahirdarrnThe research is carried out by collecting sample compressive strength testrnresult data and information on qualities of concrete ingredients and methods ofrnconcrete production through questionnaire and site observation. The findingsrnxiirnof the investigation have shown that in most of the projects sufficient testsrnare not conducted both for the coarse and fine aggregate. This indicates that arnlot has to be done to improve concrete quality in the building constructionrnindustry. From the statistical analysis of test results, the computed standardrndeviation shows 51.23 % of the projects` quality control is not good fromrnwhich 19.51% fall in the “fair” classification range and 31.72% in thern“poor” range; and that of the coefficient of variation shows 53.67 % of thernprojects` quality control is not good from which 39.02% fall in the “fair”rnclassification range and 14.65 % in the “poor” range as per thernclassification of ACI 214. This is an indication that the test results among arnsignificant portion of the investigated projects have shown large variabilityrnimplying the quality control is unsatisfactory on those projects. It is alsornobserved that, more than half, 52.17% of the projects have got defective lots,rnwhich fail to satisfy the compliance requirement set on the Ethiopian buildingrncodes and standards.rnKey words:- Cement, mineral aggregates, water, bathing, mixing, transporting,rnplacing, compacting, finishing, curing, quality control, standard deviation andrncoefficient of variation.

Get Full Work

Report copyright infringement or plagiarism