Durability of low-carbon geopolymer mortar: Different responses to cryogenic attack caused by water content and freeze-thaw mediums. (May 2023)

• Record Type: Journal Article
• Authors: Zhang, Hongen; Sarker, Prabir Kumar; Xiao, Li; Ai, Jinhua; He, Bei; Ren, Qiang; Zhu, Xinping; Zhang, Yi
• Is Part Of: Cement & concrete composites. Volume 139(2023)
• Publication Date: 2023-05
• Subjects: Geopolymer -- Cryogenic attack -- Water content -- Pore structure -- Microstructure -- Phase transition; Composite-reinforced concrete -- Periodicals; Concrete -- Periodicals; Composite materials -- Periodicals; Composites de ciment -- Périodiques; Béton -- Périodiques; Composites -- Périodiques; Béton léger -- Périodiques; Cement composites; Composite materials; Composite-reinforced concrete; Concrete; Lightweight concrete; Periodicals; Electronic journals; 620.135
• DOI: 10.1016/j.cemconcomp.2023.105065
• Languages: English
• ISSNs: 0958-9465

Abstract

Abstract: Durability is an important attribute that needs to be focused on during the life span of low-carbon geopolymer mortar (LCGM). The influence of water content (0.00%, 4.91%, and 6.46%) and freeze-thaw medium (air or water) on the performance of LCGM subjected to cryogenic attack up to −170 °C is evaluated by mass change, compressive strength, and microstructure. The results reveal that only water-saturated LCGMs subjected to air freeze-thaw medium experienced a mass loss of 0.66% and the other specimens exhibited different degrees of mass increase by up to 0.27%. Oven-dried and air-dried LCGMs in air freeze-thaw medium experienced a slight increase of compressive strength by about 4.0%. However, water-saturated LCGMs in the same condition experienced a compressive strength decrease of about 9.7%. Additionally, LCGMs exhibited an obvious compressive strength decrease of up to 24.3% in water freeze-thaw medium. The change of microstructure is responsible for the increase or decrease of compressive strength. The water transport and water-ice-water phase transition are the intrinsic motivation for LCGMs to exhibit different responses to cryogenic attack. The exposure of LCGMs to water freeze-thaw medium cryogenic attack exhibited the most severe performance deterioration, which is associated with the couple effect of internal frost-heave stress induced by phase transition and external frost-heave stress induced by ice contraction.