Study on the sulfate resistance of containment concrete with pipe and hole

Abstract

A containment concrete structure often need to embed pipes or reserve holes for the purpose of use, the pipes and holes will influence the durability of the containment concrete. Thus, the sulfate dry-wet cycles test of concrete with different diameter pipes is carried out in this paper, and the mass loss rate, corrosion resistance coefficient of compressive strength, and relative dynamic elastic modulus are used as the evaluation indexes for the sulfate resistance of concrete. The experiment results show that with an increase of pipe diameter or sulfate dry-wet cycles, the mass loss rate of concrete increases, while the relative dynamic elastic modulus and corrosion resistance coefficient of compressive strength of concrete decrease. These three indexes all indicate the pipe reduces the sulfate resistance of concrete, and the larger the diameter of pipe is, the more the sulfate resistance of concrete is reduced. It is mainly due to a weak interfacial transition zone (ITZ) is formed between the pipe and the cement-stone matrix, the sulfate more easily penetrate into the containment concrete through the ITZ. Finally, a model of the corrosion resistance coefficient of compressive strength of concrete with pipe under the sulfate dry-wet cycles is constructed by a combination of experimental and theoretical analysis. The simulation results by the model fit the experiment data very well, and it provides a method for studying the influence of embedded parts on the durability of concrete.