Saravut Jaritngam

A Study on Mixing Proportion of Roller-Compacted Concrete Pavement Made of EAF Slag Aggregate and Fly Ash by Using Taguchi Method

The aim of this study is to investigate the effect of factors in mixing proportion on the dry density of Roller-compacted concrete pavement made of EAF slag aggregate and fly ash by using Taguchi method. In this study, EAF slag with size in range of 4.75 – 19 mm was used as a substitute for natural coarse aggregate with three percentages (i.e. 0%, 50% and 100%). Cement was partially replaced by fly ash at three content levels (i.e. 0%, 20% and 40%). Four factors are considered to study including the percentage of EAF slag aggregate, the percentage of binder (cement + fly ash), the fly ash ratio, and the moisture content. And, three levels of four factors were proposed to study the influence of them on the dry density of RCCP. Thus, nine mixtures conforming the orthogonal array L9 of Taguchi method were prepared to determine the dry density of RCCP by Proctor test. The results were assessed by the analysis of variance (ANOVA). The results of this research indicated that increasing of the percentage of EAF slag as aggregate replacement led to rise the dry density, whereas increasing of the fly ash ratio as cement substitution resulted in the decrease of dry density. The percentage of binder is range of 10-14% and moisture content in range of 6-8% affected slightly on the dry density. When the moisture content exceeded 8% leading to the reduction of the dry density.