Repeated Autogenous Healing in Strain-Hardening Cementitious Composites by Using Superabsorbent Polymers

Abstract

Autogenous healing is an already-present feature in strain-hardening cementitious materials, but it is an inferior mechanism because it can only heal small cracks in the presence of water. A cementitious material with synthetic microfibers and superabsorbent polymers (SAPs) could provide a solution. In this study, the ability of repeatable promoted autogenous healing in fiber-reinforced, strain-hardening cementitious materials with and without SAPs is investigated by comparing their mechanical properties after they are subjected to two cycles of loading under a four-point-bending test. The results indicate that SAP particles promote self-healing. The main mechanisms of the autogenous healing are the hydration of unhydrated cementitious materials in cracks and the precipitation of calcium carbonate on the crack faces. The healed specimens are able to regain some of their mechanical properties (up to 75%). Even second reloading of those healed samples leads to partial additional regain in mechanical properties (up to 66%).

From straw in bricks to modern use of microfibers in cementitious composites for improved autogenous healing – A review

“…A new topic is the investigation of the combined effect of microfibers and superabsorbent polymers (SAPs) [162][163][164][165]. As those polymers swell in contact with water after crack formation, the crack is self-sealed [166][167][168][169][170].…”

Repetitividad de la capacidad autorreparante de hormigones reforzados con fibras con aditivo cristalino

“…Posteriormente, será necesario comprobar si el mecanismo de autorreparación se mantiene a lo largo del tiempo tras varios ciclos de carga-descarga (repetitividad de la autorreparación). A día de hoy todavía hay muy pocos trabajos que traten la repetitividad [7,11].…”

Effects of autogenous healing on the recovery of mechanical performance of High Performance Fibre Reinforced Cementitious Composites (HPFRCCs): Part 1

“…Li and Li [14] and Yang et al [15] also found that even in aggressive conditions, such as high-chloride atmosphere or water, the autogenous healing capacity of ECCs is maintained, at level obviously depending on the crack width and aggressiveness of the environment. Snoeck et al [16] and Snoeck and de Belie [17] also quite recently studied combined synergistic effects of fibres and Super Absorbent Polymers (SAPs) in ECCs whereas Ferrara [18] combined fibres and crystalline admixtures to enhance the selfhealing performance of HPFRCCs.…”