摘要详情
292 / 2023-02-17 00:13:12
Enhancing recycled fine concrete aggregate by a two-step wet carbonation process
wet carbonation; recycled fine concrete aggregate; upcycling; chemical treatment
摘要录用
The construction industry is eager to develop upcycling techniques for transforming secondary by-products derived from concrete waste into value-added new products due to the shortage of practical and economical solutions. Currently, recycled concrete aggregates (RCA) were mainly used in low-graded applications, especially the fine portion of the RCA due to a higher mortar content.
This paper presents a study aiming to enhance the quality of recycled fine aggregate (FRCA) by utilizing a wet carbonation process developed by the authors previously. The fine recycled concrete aggregate (FRCA) ranging from 0.15-5 mm was prepared through demolishing a concrete with a known mixture design. The FRCA was treated by a Na2CO3 solution. The particle size, water absorption, and density of the FRCA were tested and compared. The chemical characteristics of the RFA after wet carbonation were analyzed by a series of experiments. The results showed that the density and the water absorption properties of the FRCA improved significantly
The chemical compositions of the FRCA were analyzed by XRF, XRD, and TGA before and after the wet carbonation. The results revealed an increase in carbonation production and a significant reduction in cement hydration products. The microscopic observation of the FRCA showed a densified surface layer with carbonation products after wet carbonation. The by-product of calcite and silica-rich gel were also collected and analyzed.
A rough estimation of the environmental and economic impact of wet carbonation on FRCA was conducted. The proposed approach was expected to avoid millions of disposal charges and provide FRCA with solid properties. Meanwhile, the calcite-rich residue and silica-rich gel showed high potential industrial values. Moreover, the material and energy consumption of the wet carbonation process were environmentally friendly.
This paper presents a study aiming to enhance the quality of recycled fine aggregate (FRCA) by utilizing a wet carbonation process developed by the authors previously. The fine recycled concrete aggregate (FRCA) ranging from 0.15-5 mm was prepared through demolishing a concrete with a known mixture design. The FRCA was treated by a Na2CO3 solution. The particle size, water absorption, and density of the FRCA were tested and compared. The chemical characteristics of the RFA after wet carbonation were analyzed by a series of experiments. The results showed that the density and the water absorption properties of the FRCA improved significantly
The chemical compositions of the FRCA were analyzed by XRF, XRD, and TGA before and after the wet carbonation. The results revealed an increase in carbonation production and a significant reduction in cement hydration products. The microscopic observation of the FRCA showed a densified surface layer with carbonation products after wet carbonation. The by-product of calcite and silica-rich gel were also collected and analyzed.
A rough estimation of the environmental and economic impact of wet carbonation on FRCA was conducted. The proposed approach was expected to avoid millions of disposal charges and provide FRCA with solid properties. Meanwhile, the calcite-rich residue and silica-rich gel showed high potential industrial values. Moreover, the material and energy consumption of the wet carbonation process were environmentally friendly.
重要日期
-
会议日期
03月11日
2023
至03月13日
2023
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02月17日 2023
初稿截稿日期
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02月17日 2023
提前注册日期
-
03月13日 2023
注册截止日期
主办单位
深圳大学
香港理工大学
香港理工大学
