RSM-based modeling and optimization of self-consolidating mortar to predict acceptable ranges of rheological properties

Abstract

Using a high or low amount of cementitious material, water-cement ratio (W/C), and superplasticizer (SP) cause instability and reduction in compressive strength of concrete according to their impact factor and interaction. However, making a concrete with the optimum amount of variables could improve its properties. So, optimization of concrete ingredient due to absence of proper mix design code is required. The remarkable features of response surface method (RSM) are modeling and optimization. This study was carried out with the aim of investigating rheological and hardened properties of self-consolidating mortar (SCM) using RSM with four factors (silica fume, slag, SP and W/C). Rheological criteria of EFNARC code were used to specify the optimum restriction. According to statistical analysis and validation of equations, it can be concluded that RSM is a confident and efficient method to evaluate the properties of SCM. In addition, according to model, the silica fume increased EFNARC code limitation ranges by improving the rheological properties, however, slag had an almost neutral role. In the best case, the addition of silica fume, reduced the segregation up to 5 times. Although silica fume increased the compressive strength up to 45%, slag totally decreased the compressive strength.