Experimental and statistical studies of using the non-conventional water and zeolite to produce concrete

Abstract

In the present study, the effect of simultaneous use of different non-conventional water types and zeolite percentages on the compressive strength of concrete was investigated. The experiment was conducted in two cement contents for long-term curing ages up to 365 days. Finally, data of 1176 cubic samples were statistically analyzed. Also, the relationship between water type, zeolite percentage, cement content, and curing age as independent variables and compressive strength of concrete as the dependent variable was extracted by the single and multiple linear regressions. Dummy coding was used in the regression procedure. Results showed that despite the significant decreasing effect of zeolite on the compressive strength of concrete in low cement content, a negative effect on this property was not seen up to zeolite usage 20% in high cement content. Also, while in low cement content, the use of all types of non-conventional water led to an increase in the compressive strength of concrete, in the high cement content, this property was reduced within the permissible limit of 10% by all types of non-conventional mixing water. Three-way interaction of zeolite percentage, water type and cement content on compressive strength of concrete revealed that negative effect of the simultaneous use of zeolite and non-conventional water compared to the condition of tap water and without zeolite usage mostly was less in the cement content 350 Kg.m−3 than 250 Kg.m−3. Finally, it was concluded that permissible limits of mixing water impurities of which are presented in the different standards possibly have not adequately credited for all conditions.