Compressive behaviour and microstructures of concrete incorporating pretreated recycled powder/aggregates: The coupling effects of calcination and carbonization

Zhang，Baifa1; Feng，Yuan1; Xie，Jianhe1; Chen，Wei1; Xue，Zixin1; Zhao，Gexiao2; Li，Yun3; Li，Jianglin1; Yang，Jian4

2023-06-01

10.1016/j.jobe.2023.106158

Journal of Building Engineering   影响因子和分区

2352-7102

The incorporation of recycled powder (RP), recycled fine aggregate (RFA), and recycled coarse aggregate (RCA) can adversely affect the performance of cement-based materials. In this study, RP, RFA, and RCA (with or without pretreatment) are used to replace cement, natural fine aggregate (NFA), and natural coarse aggregate (NCA), respectively, to prepare recycled concrete (RC). With an increase in the replacement ratio of recycled materials, the mechanical properties of recycled cement paste (RCP), recycled mortar (RM), and RC are found to gradually decrease. Pretreatment (calcination and carbonization) of recycled materials favours the improvement of their physical and chemical properties, in which the coupling pretreatment of calcination and carbonization is found to lead to the best improvement in material properties. Among the RCs containing 50% RCA, the RCA carbonized for 24 h after calcination at 400 °C favours the best performance improvement for RC, with the compressive strength, elastic modulus, and compressive toughness increased by 35.8%, 19.3%, and 39.9%, respectively. The coupling effect of pretreatment results in the bonding between the matrix and RCA becoming closer, accompanied by an effective improvement in the ITZ. However, a too high calcination temperature (>600 °C) will negatively affect the performance of RC, whereas carbonization for a prolonged period of time barely alters the performance of RC. These results indicate that the coupling pretreatment of recycled materials favours the properties of the as-obtained RC, and calcination at 400 °C with carbonization at 6 h is the optimal pretreatment for recycled materials in terms of economic value and mechanical properties.

Microstructure Pretreatment Recycled coarse aggregate (RCA) Recycled concrete Stress‒strain curve

SCI ; EI

英语

其他

Science and Technology Planning Project of Guangdong Province[2022A0505050077] ; Guangdong Basic and Applied Basic Research Foundation[2019B151502004,2023A1515012180] ; National Natural Science Foundation of China[12072078]

Construction & Building Technology ; Engineering

Construction & Building Technology ; Engineering, Civil

WOS:001042194100001

ELSEVIER

20231013692130

Calcination ; Carbonization ; Cements ; Chemical bonds ; Compressive strength ; Concrete aggregates ; Recycling

Concrete:412 ; Cement:412.1 ; Industrial Wastes:452.3 ; Physical Chemistry:801.4 ; Chemical Reactions:802.2 ; Chemical Operations:802.3 ; Materials Science:951

2-s2.0-85149442555

Scopus

1.School of Civil and Transportation Engineering,Guangdong University of Technology,Guangzhou,Guangdong,510006,China
2.Guangdong Jiandong Construction Supervision Co,Ltd,Guangzhou,Guangdong,510599,China
3.Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou) / Shenzhen Key Laboratory of Natural Gas Hydrates,Academy for Advanced Interdisciplinary Studies,Southern University of Science and Technology,Shenzhen,518055,China
4.School of Civil Engineering,University of Birmingham,Birmingham,B15 2TT,United Kingdom

Zhang，Baifa,Feng，Yuan,Xie，Jianhe,et al. Compressive behaviour and microstructures of concrete incorporating pretreated recycled powder/aggregates: The coupling effects of calcination and carbonization[J]. Journal of Building Engineering,2023,68.

Zhang，Baifa.,Feng，Yuan.,Xie，Jianhe.,Chen，Wei.,Xue，Zixin.,...&Yang，Jian.(2023).Compressive behaviour and microstructures of concrete incorporating pretreated recycled powder/aggregates: The coupling effects of calcination and carbonization.Journal of Building Engineering,68.

Zhang，Baifa,et al."Compressive behaviour and microstructures of concrete incorporating pretreated recycled powder/aggregates: The coupling effects of calcination and carbonization".Journal of Building Engineering 68(2023).