In-situ assessment of the water-penetration resistance of polymer modified cement mortars by μ-XCT, SEM and EDS. (November 2020)

• Record Type: Journal Article
• Authors: Peng, Yu; Zhao, Guorong; Qi, Yuxuan; Zeng, Qiang
• Is Part Of: Cement & concrete composites. Volume 114(2020)
• Publication Date: 2020-11
• Subjects: Anti-penetration -- Polymers -- X-ray computed tomography -- Microstructure; 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.2020.103821
• Languages: English
• ISSNs: 0958-9465

Abstract

Abstract: Anti-water-penetration techniques are important to raise the durability of cement-based materials (CBMs). Here the water penetration resistances of cement mortars with ethylene-vinyl acetate copolymer (EVA) and styrene butadiene rubber (SBR) were in-situ and non-destructively probed by micro-focus X-ray computed tomography (μ-XCT). Caesium Chloride (CsCl) was mixed in water to enhance the contrast gradients of μ-XCT images. SEM and EDS tests were provided to assess the mortar microstructure changes induced by water penetration. Results show that the CsCl enhancement helps trace the water penetration fronts, while exerting minor influences on the water penetration kinetics. The polymers can greatly raise the resistance against the water penetration into the cement mortars. The pore blocking induced by the formation of polymer films on the surfaces of cement grains and aggregates may account for the enhanced water-penetration resistance. The findings of this work provide a new method to track the water penetration in CBMs by μ-XCT and deepen the knowledge in the anti-water mechanisms of polymer-modified cement materials. Highlights: X-ray attenuation enhancement was used to visually and in-situ probe the water ponding in porous mortars. Anti-permeations of EVA and SBR mortars were quantified. Polymers enhance anti-penetration by blocking the ITZs and open pores.