Experimental Study On Some Hardened Properties Of Air Entrained Recycled Aggregate Concrete

Abstract The use of recycled aggregate as a replacement for natural aggregates has been known for a number of years. The future benefits of using recycled aggregate cannot be overemphasized. This study was an attempt to evaluate some hardened properties if Air Entrained Recycled Aggregate Concrete. In order to minimize the number of samples required per experiment Taguchi orthogonal optimization technique was adopted for this investigation. In this technique only a few combination values of control factors required were chosen. The theory behind this technique which needs to consider both the process of designing the experiment and the way of statistically analyzing the experimental data of response is based on the usage of the orthogonal arrays the analysis of variance ANOVA and the significance test with F statistics. Also signal S to noise N ratio SN were also applied in the analysis. The objective of SN analysis is to determine the most optimum set of the operating conditions from variations of the influencing factors within the results. The influence of the order of materials used in concrete production made with recycled aggregates with respect to compressive and flexural strengths were analyzed and discussed. The results indicate that the higher the air contents the lower the compressive and tensile strengths respectively.