Investigation of self-healing ability of hydroxyapatite blended cement paste modified with graphene oxide and silver nanoparticles

Abstract

Cracks that occur over time are difficult to detect and repair, and they threaten the safety and durability of buildings and limit sustainable building design. This study investigates the feasibility of using hydroxyapatite (HAp) with graphene oxide and silver nanoparticles to self-heal narrow cracks that are difficult to detect. Ultrasonic pulse velocity, compressive strength, portlandite content, the percentage of water absorption and porosity recovery was observed with increases of 77.5%, 259.6%, 406.28%, 35.1% and 22.0% respectively for the 0.1 wt% of HAp content. Healing efficiency of micro-crack width on surface of cement pastes was reached 62.52%, by incorporating with HAp and silver nanoparticles. The healing property was found to be associated with the hydrogen bonds, electrostatic interactions with negatively charged PO4-3 and OH– ions groups and development of portlandite formed by the reaction between Ca2+ and OH– ions.