Sustainable Study of Self-Healing Concrete in Hot Desert Climate

Abstract

The hot and dry desert climate is characterized by high temperature and high humidity. This affects the strength of concrete negatively by the difficulty of providing proper curing and by generating early micro-cracks due to the high temperature. These two issues have been addressed in this study by adding calcite precipitating bacteria to deal with the micro-cracks and by adding Ultra-High Absorbent Polymer (UHAP) to provide the concrete with the needed internal curing. Durability of concrete is what categorizes it as an effective construction material. Durability of the concrete is vastly affected by micro-cracks and macro cracks. Concrete is very strong in handling compressive stresses but on the other hand, it is quite weak when it comes to tensile stresses. While cracks caused by the increase in tensile stresses may cause structural failure, micro-cracks should also be taken into consideration. They cause higher permeability and durability concerns, leading to corrosion of reinforced steel bars. In addition, micro-cracks propagate to become macro cracks that induce failure in structural members. In a humid desert environment such as the UAE environment, micro-cracks are very influential in structures as they provide channels for moisture leading to significant damage. New environmentally friendly methods must be implemented in order to reduce micro-cracks in early stages before they expand and before they require maintenance. Thus, in this study, the effect of adding self-healing agents in the concrete mix is investigated. The two measures considered in this study projected positive impact on the concrete compressive strength in the hot and dry desert climate.