OPTIMIZATION OF CEMENT CONTENT IN CONCRETE USING ADDITIVES

Abstract

The objective of the present work was to systematically investigate the issue of minimum cement content requirements as reduction of CO2 released during the production of cement is major issues of construction industry. In this work behavior of concrete grades was studied by varying different parameters such as water to binder ratio (W/B), superplasticizers content (SP),-cement content, fine aggregate content and mineral admixtures-content (fly ash (FA), ground granulated blast slag (GGBS), and silica fume (SF)) while aiming to reduce the cement.content in concrete. An experimental program was designed to determine the optimum mix proportions of concrete with minimum cement content. For this purpose, design of experiments based - on Taguchi method was formulated for M20 and M40 grade of concrete. A standard L16 (45) orthogonal Array (OA) was selected for the experimental programme with five parameters at four levels,. giving rise to a total of 16 trial mixes. Therefore, sixteen trial mixes were.chosen for casting and testing in each case, i.e. for each concrete grade and pozzolana type. - . . Results were analyzed manually as well as by Taguchi- method in terms of Signal. to, Noise ratio:.. (SIN). Influences of the parameters on concrete-mixes obtained.in. both cases are comparable to.. each other. The study showed that both mineral- and chemical:'admixtures can- effectively. be used.: to reduce the cement content in concrete. For the materials and range. of parameters used in the investigation, the present study has established -optimum mixes both in terms of target strength-and required workability using minimum cement content. The test results indicated that the most influencing parameter for concrete mixes is mineral admixtures content whereas, fine aggregate is the least influencing parameter. The study showed that-Taguchi method can be used efficiently and economically for designing. the experiments and determining -interaction of the parameters. v. 111