Experimental study on carbonation of steel fiber reinforced concrete

Abstract

With the steel fiber reinforced concrete (SFRC) used more and more widely in some large-span structures, large tunnel linings, dam structures, military engineering, and some other major projects, its durability arouses more and more concerns. In this paper carbonation test of SFRC was conducted. The rule for the mixing amount of steel fiber (0, 0.5, 1.0, 1.5, and 2.0%) to affect the carbonation depth of concrete and the strength developing rule of SFRC after carbonation test were researched. To analyze the property change rules from micro perspective of SFRC after carbonation, the pore structure of SFRC after carbonation was tested. The results show that appropriate amount of steel fiber can retard the speed of concrete carbonation; the concrete carbonation speed is the slowest when the fiber content is 1.5%, and the carbonation speed is accelerated when the fiber content is increased to 2%. Carbonation can change the pore structure of SFRC, total porosity, total pore volume, and total pore areas reduced and makes the pore structure of concrete going more reasonable. Carbonation can improve the splitting tensile strength of SFRC to certain extent. © 2014 4th International Conference on the Durability of Concrete Structures.