Self-healing potential of supplementary cementitious materials in cement mortars: Sorptivity and pore structure. (May 2021)

• Record Type: Journal Article
• Authors: Maddalena, Riccardo; Taha, Hussameldin; Gardner, Diane
• Is Part Of: Developments in the built environment. Volume 6(2021)
• Publication Date: 2021-05
• Subjects: Autogenous healing -- Mortar -- Sorptivity -- Cement replacement; Civil engineering -- Periodicals; Sustainable construction -- Periodicals; 624.05
• DOI: 10.1016/j.dibe.2021.100044
• Languages: English
• ISSNs: 2666-1659

Abstract

Abstract: This paper presents the autogenic self-healing potential of Portland cement (PC) blends made with conventional supplementary cementitious materials (SCMs), to improve the water-tightness by reducing the overall pore size. Mortar samples were prepared by mixing PC, sand and water, and partially replacing PC by either silica fume (SF), pulverised fuel ash (PFA), or ground granulated blast-furnace slag (GGBS). Damaged samples were subjected to a water bath to heal microcracks and recover the water-tightness, by further hydration of the starting minerals. Water absorption and density measurements in undamaged, damaged and healed conditions were used to determine the autogenous healing potential of SCMs mixes, showing a post-healing absorption recovery of up to 68% compared to the mix with PC only. Thermal analysis, XRD and MIP measurements confirmed the capability of SCMs to promote the formation of hydrated phases, and reduce the overall pore size by more than 88% compared to PC mixes. Highlights: The self-healing potential of silica fume, fly ash and GGBS cement mixes is investigated. Use of supplementary cementitious materials improves cement water transport properties. Sorptivity and thermal analyses are used to assess the healing process. After healing the additional hydrated products increased the pore surface area.