Performance of hydraulic lime by using carbide slag. (1st July 2022)

• Record Type: Journal Article
• Authors: Luo, Kai; Cheng, Xiongying; Li, Jun; Lu, Zhongyuan; Deng, Xin; Hou, Li; Jiang, Jun
• Is Part Of: Journal of building engineering. Volume 51(2022)
• Publication Date: 2022-07-01
• Subjects: Hydraulic lime -- Carbide slag -- Performances -- Pore structure; Building -- Periodicals; 690.05
• DOI: 10.1016/j.jobe.2022.104208
• Languages: English
• ISSNs: 2352-7102

Abstract

Abstract: The preparation of lime-based materials through calcining limestone or siliceous/clay limestone (including air lime and hydraulic lime) directly/indirectly emits large amounts of CO2 due to limestone decomposition and energy consumption. In this study, a sinter-free hydraulic lime (HL) was proposed by mixing carbide slag (CS) and white Portland cement (WPC), which can effectively utilize solid wastes and in future that may prove to be effective for CO2 mitigation. Results showed the flexural strength of HL mortars decreased from 6.3 MPa to 0.5 MPa, compressive strength decreased from 42.0 MPa to 2.2 MPa, air permeability increased from 0.440 to 2.468 Ln (pressure)/min and water permeability increased from 6.576 × 10 −7 to 47.362 × 10 −7 m 3 /min 0.5 with the increase of CS from 20% to 40%, 60% and 80% in HL. However, the mechanical properties still meet the standard requirements when the CS content is 80%. Carbonation treatment can refine pore size and improve mechanical properties of HL mortar. CS is expected to become the main raw material for HL preparation. Highlights: Carbide slag (CS) was appropriate for the preparation of hydraulic lime (HL). The addition of CS can adjust the pore structure of HL. The addition of CS will increase the reserves of HL to CO2 . CS is conducive to improving the air permeability and water permeability of HL.