Study on the Causes that Effect of Carbonation on the Elastic Modulus of Different Cured Concrete and Mortar Containing High Ggbs Content

Concrete using Ground granulated blast-furnace Slag (GGBS) has been widely used for a long time because it is expected to improve long-term compressive strength, high durability, and reduce environmental impact. However, previous studies have shown that GGBS is sensitive to the surrounding environment and easily carbonated, and it is necessary to know its compressive strength and elastic modulus in such an environment. In this study, concrete and mortar with different replacement ratios of GGBS were prepared to compare the compressive strength and elastic modulus of concrete and mortar. The specimens were cured under various environmental conditions, such as in tap water, in air and accelerated carbonation curing. The compressive strength and elastic modulus tests were conducted. As a result, a decrease in the elastic modulus was observed for specimens with a higher replacement ratio of GGBS on carbonated curing. This is thought to be caused by differences in the physical properties of the aggregate and cement paste, shrinkage of the matrix, or microscopic cracking due to hydration, and an investigation is underway to determine the cause.