Control of cracking and leakage due to shrinkage and temperature effects in structures using ECC and GFRP materials

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Restrained temperature and shrinkage strains are one of the major reasons for cracking in reinforced concrete structures. Such effect can cause serviceability problems which is of particular significance in the structural design of lifeline facilities such as liquid continuing structures and nuclear power plants. The prediction and control of crack widths in reinforced concrete structures made of normal concrete has been the subject of research for many years. However, there is still a lack of consensus on the design of reinforcement in base-restrained walls for crack control. The need for such study is even more for structures made of advanced materials such as ECC and GFRP. This study aims to investigate this matter through several experimental and analytical case studies. Three large-scale reinforced wall specimens with different materials and mix compositions will be casted, properly cured, and tested to determine how different types of material can affect the cracking pattern, the crack opening, and the strain profile produced by shrinkage and thermal effects. There are two main issues to be addressed through this study: 1) the width and pattern of temperature and shrinkage cracking in ECC and FRP-reinforced walls as compared to the customary normal concrete walls typically used in today's practice, 2) cracking due to thermal effects derived from two main factors - seasonal temperature variations and early-age thermal contraction. The goal is to contribute to the improvement of concrete technology and to provide engineers with practical design guidelines. The main objective is to study the potential improvements in cracking behavior of base-restrained walls using newly developed materials such as ECC and GFRP to withstand extreme weather conditions, similar to those encountered in Canada. In this relation, it is proposed that the time-dependent effects due to shrinkage and temperature change be induced in specimens made of different materials and the development of cracking in them be monitored and examined over time.