A NEW APPROACH TO CONCRETE MIX DESIGN USING COMPUTER TECHNIQUES

Abstract

Concrete is an essential part of most civil engineering works. Mix design of concrete is usually specified in terms of prescription or performance. The purpose of this work is to develop a model that is capable of reproducing any expected concrete strength within a specified range of cement content. In addition such a model can be used to generate data on mix proportions and their corresponding compressive strength, thereby furnishing useful information for general purpose, safe-ready-to-use mix design. Such data were generated and checked against values obtainable from standard mix design practice and found to agree very well within the limits of experimental error. A test of the statistical significance of the developed model using F-statistic shows that the regression as a whole is highly significant. The work culminated in the development of a concrete mix design chart which presents mix proportions for various grades of concrete ranging from compressive strength values of 10N/mm² to 50N/mm². This chart is expected to be of immense help to site supervisors involved in concrete production since the use of the chart as a guide to batching the ingredients of concrete, will eliminate the need for tedious mix design procedures and at the same time ensure that correct quantities of the required materials are used for concrete production.