Modeling the effect of silica fume on the compressive, tensile strengths and durability of NSC and HSC in various strength ranges

Abstract

The objective of this study is to identify and quantify the effect of silica fume content (SF), water–cement-ratio (w/c) and curing time (t) on the compressive and tensile strengths of concrete at different strength ranges varied from 4 to 100 MPa. In this study, over 1000 data were used to characterize the compressive and tensile strengths behavior. The range of w/c for modified concrete with different percentage of silica fume up to 40% (by dry weight of cement) was in the range of 0.17–0.80%, compressive and tensile strengths were in the range of 4–100 MPa, and 1–7 MPa, respectively. Vipulanandan model correlated the relationship between mechanical properties of concrete modified with SF with a varied range of w/c and curing time and the result were compared with the Hoek–Brown correlation model used in the literature. Based on the coefficient of determination (R2) and root mean square error (RMSE) the compressive strength (σc), tensile strength (σt) of concrete as a function of w/c, percentage of silica fume and curing time using nonlinear (NLM) relationship quantified very well. Based on the NLM parameters, the effect of SF was less than w/c and curing time on the compressive strength of modified concrete with SF in different strength range. According to the coefficient of determination (R2) and root mean square error (RMSE), the Vipulanandan correlation model and Hoek–Brown model both are very close in predicting the mechanical behavior of concrete modified with SF for normal and high strengths concrete (NSC and HSC).