Recycling of plastic waste concrete to prepare an effective additive for early strength and late permeability improvement of cement paste. (12th September 2022)

• Record Type: Journal Article
• Authors: He, Xingyang; Li, Weilong; Su, Ying; Zheng, Zhengqi; Fu, Jianjian; Zeng, Jingyi; Tan, Hongbo; Wu, Yan; Yang, Jin
• Is Part Of: Construction & building materials. Volume 347(2022)
• Publication Date: 2022-09-12
• Subjects: Plastic waste concrete -- Early strength -- Permeability -- Microstructure -- Effective additive; Building materials -- Periodicals; 624.18
• DOI: 10.1016/j.conbuildmat.2022.128581
• Languages: English
• ISSNs: 0950-0618

Abstract

Highlights: A preparation process of high value-added specific additive was designed from plastic waste concrete. The 12 h compressive strength of cement was increased by 356 % after adding the PWC based additive. The addition of PWC additive can optimize the pore structure and improved the compactness of matrix. The resistance to chloride ion penetration at the later stage was also enhanced. Abstract: Plastic waste concrete is an alkaline solid–liquid mixed waste generated in the concrete production process. The recycling of plastic waste concrete in building materials can help reduce environmental pollution. In present work, wet-grinding process was utilized to set up a high-value added wet-grinding plastic waste concrete (WPWC) based specific additive with a D50 of 1.07 μm. The physical and chemical properties of WPWC based additive and its effects on the rheological property, hydration process, compressive strength, microstructure and permeability of Portland cement were investigated. The results showed that after adding WPWC additive, the compressive strength of 12 h was increased by 356 %, and more hydration products were produced. Different from common early-strength agents, the addition of WPWC additive can provide combined effects of nucleation induction and physical filling, which optimized the pore structure and improved the compactness of matrix. In addition, the resistance to chloride ion penetration at the later stage was also enhanced. This indicated that the incorporation of WPWC additive is an effective method to improve both the early strength and late permeability of cement.