Statistical Investigation of the Effects of w/c, Cement Dosage and Fibers on Bond Strength and Carbonation Coefficient of Hybrid Fiber Concretes

Abstract

Fiber reinforced concretes are preferred due to high tensile strength in structural elements. Alongside to tensile strength, supplying good adherence with concrete and its durability against time are also expected properties. A four-factor experimental test program was created in this study to investigate the effect of fiber type and quantity on the strength and durability performance of hybrid fiber concretes (FRC). In addition to steel fiber ratio (STF) and glass fiber ratio (GF), basic criteria of concrete such as water/cement ratio and cement dosage were chosen as independent variables. Flexural and compressive strength, bond strength, stripping time of steel reinforcement and 180, 270 and 360-day carbonation depths of FRC were investigated experimentally. The Carbonation coefficients of each FRC were calculated and a correlation was obtained for a general "Ke" carbonation coefficient by Multi Linear Regression. Average of K was 0.219 mm & RADIC;days. Stripping time of steel reinforcement from FRC was two times longer in samples containing only STF than samples containing only GF. With the dual combination of STF and GF, this time has been increased approximately 4 times.