Variables Affecting the Efficiency of Shape Memory Polymer Healing in Concrete

Abstract

Concrete is the most used material in the construction industry worldwide. Although its durability is high compared to other building materials, it is not entirely immune to damage and the periodic maintenance of concrete structures is unavoidable to ensure they remain usable and in good condition. To improve the durability of concrete and solve problems including costs incurred in concrete construction and maintenance, as well as with global pollution due to cement production - a crucial component in concrete production - researchers are working to develop self-healing concrete and other smart materials. This research sought to investigate the factors influencing the efficiency of shape memory polymers in healing concrete. The use of shape memory polymers in self-healing concrete has been investigated at laboratory level in the past. This study is intended to provide useful data concerning the industrialisation of shape memory polymers in healing concrete. Factors studied that are considered to affect the efficiency of shape memory polymers at industrial levels include the size of concrete elements, the temperature of activation, and the quantity of SMPs. Three investigations were carried out in this research, concluding that, as the size of specimens increases, SMP self-healing efficiency decreases. The optimum temperature was 120° C for SMP activation while a further increase in temperature may cause other cracks and results in a drop in the efficiency. Stress produced by SMP tendons was less than calculated stress in the analytical analysis due to manufacturing errors and different pretension quantities of each specimen. Further manufacturing and investigation tool development is required to enhance the capability of SMP healing in concrete.