Effect of limestone powder on fracture and flexural behaviour of PVA fibre-reinforced sulfoaluminate cement. Issue 24 (12th December 2020)

• Record Type: Journal Article
• Authors: Li, Yuelin; Deng, Dehua; Sierens, Zeger; Zhao, Xuefang; Li, Jiabin
• Is Part Of: Magazine of concrete research. Volume 72:Issue 24(2020)
• Page Start: 1243
• Page End: 1259
• Publication Date: 2020-12-12
• Subjects: bond -- composite materials -- toughness; Concrete -- Periodicals; Concrete construction -- Periodicals; Concrete -- Testing -- Periodicals; 624.1834
• DOI: 10.1680/jmacr.18.00332
• Languages: English
• ISSNs: 0024-9831

Abstract

Abstract : In this paper, the effect of the partial substitution of cements with limestone powders (LSPs) with different replacement levels and fineness on the fracture and flexural properties of non-oil-coated polyvinyl alcohol (PVA) fibre-reinforced sulfoaluminate cement (SAC) was experimentally investigated. The properties of the matrix, including the pore structure and fracture behaviour, were evaluated by means of mercury intrusion porosimetry and the double-K fracture model, respectively. The fibre–matrix bonding properties were measured and characterised using pull-out tests on fibre bundles and scanning electron microscopy. The test results show that an LSP replacement level of 20% significantly increases the flexural strength of the PVA fibre-reinforced SAC, while no increase in the ductility is found. In comparison, a higher LSP replacement level – that is, 40% – is more efficient in improving the ductility of the composite in terms of the deformation capacity and pseudo strain-hardening effect; however, this replacement level results in a reduction in the flexural strength of the composite. By utilising a finer LSP with a replacement level of 40%, an improvement in both the flexural strength and ductility of the composite is achieved in comparison to that of the reference samples.