Influence of acid treatment and carbonation on the properties of recycled concrete aggregate
Abstract
Recycled concrete aggregate (RCA), obtained by crushing of original (old) concrete, consists of natural aggregate grains and a cement mortar matrix. The presence of old adhered cement mortar, which has higher porosity than natural aggregate, causes unfavourable properties of RCA. The research conducted in order to improve the quality of RCA and to enable its greater application in the construction industry is presented in this paper. Therefore, RCA was subjected to quality improvement treatments with hydrochloric acid and carbon dioxide (accelerated carbonation). The first procedure was aimed at partially removing the adhered cement mortar and the second at reinforcing the cement matrix. The physical, mechanical and chemical properties of all three types of RCA were tested. After the pre-soaking acid treatment (0.1 mol/dm(3) HCl), RCA showed reduced water absorption (up to 3%); the process of accelerated carbonation also led to reduced water absorption (13-20%) as well as to improved m...echanical properties (similar to 10%). A scanning electron microscopy investigation revealed that the carbonation process, as expected, significantly reduces porosity of RCA. The overall results show that if RCA is obtained by crushing of compact, high-quality concrete, the procedures of aggregate quality improvement are not necessary.
Keywords:
accelerated carbonation / pre-soaking in acid / recycled concrete aggregateSource:
Chemical Industry and Chemical Engineering Quarterly / CICEQ, 2018, 24, 1, 23-30Publisher:
- Savez hemijskih inženjera, Beograd
Funding / projects:
- Research on condition assessment and improvement methods of civil engineering structures in view of their serviceability, load-bearing capacity, cost effectiveness and maintenance (RS-36048)
- Utilization of by-products and recycled waste materials in concrete composites in the scope of sustainable construction development in Serbia: investigation and environmental assessment of possible applications (RS-36017)
DOI: 10.2298/CICEQ161202014R
ISSN: 1451-9372
WoS: 000430423900003
Scopus: 2-s2.0-85046015241
Collections
Institution/Community
GraFarTY - JOUR AU - Radević, Aleksandar AU - Despotović, Iva AU - Zakić, Dimitrije AU - Orešković, Marko AU - Jevtić, Dragica PY - 2018 UR - https://grafar.grf.bg.ac.rs/handle/123456789/962 AB - Recycled concrete aggregate (RCA), obtained by crushing of original (old) concrete, consists of natural aggregate grains and a cement mortar matrix. The presence of old adhered cement mortar, which has higher porosity than natural aggregate, causes unfavourable properties of RCA. The research conducted in order to improve the quality of RCA and to enable its greater application in the construction industry is presented in this paper. Therefore, RCA was subjected to quality improvement treatments with hydrochloric acid and carbon dioxide (accelerated carbonation). The first procedure was aimed at partially removing the adhered cement mortar and the second at reinforcing the cement matrix. The physical, mechanical and chemical properties of all three types of RCA were tested. After the pre-soaking acid treatment (0.1 mol/dm(3) HCl), RCA showed reduced water absorption (up to 3%); the process of accelerated carbonation also led to reduced water absorption (13-20%) as well as to improved mechanical properties (similar to 10%). A scanning electron microscopy investigation revealed that the carbonation process, as expected, significantly reduces porosity of RCA. The overall results show that if RCA is obtained by crushing of compact, high-quality concrete, the procedures of aggregate quality improvement are not necessary. PB - Savez hemijskih inženjera, Beograd T2 - Chemical Industry and Chemical Engineering Quarterly / CICEQ T1 - Influence of acid treatment and carbonation on the properties of recycled concrete aggregate EP - 30 IS - 1 SP - 23 VL - 24 DO - 10.2298/CICEQ161202014R ER -
@article{ author = "Radević, Aleksandar and Despotović, Iva and Zakić, Dimitrije and Orešković, Marko and Jevtić, Dragica", year = "2018", abstract = "Recycled concrete aggregate (RCA), obtained by crushing of original (old) concrete, consists of natural aggregate grains and a cement mortar matrix. The presence of old adhered cement mortar, which has higher porosity than natural aggregate, causes unfavourable properties of RCA. The research conducted in order to improve the quality of RCA and to enable its greater application in the construction industry is presented in this paper. Therefore, RCA was subjected to quality improvement treatments with hydrochloric acid and carbon dioxide (accelerated carbonation). The first procedure was aimed at partially removing the adhered cement mortar and the second at reinforcing the cement matrix. The physical, mechanical and chemical properties of all three types of RCA were tested. After the pre-soaking acid treatment (0.1 mol/dm(3) HCl), RCA showed reduced water absorption (up to 3%); the process of accelerated carbonation also led to reduced water absorption (13-20%) as well as to improved mechanical properties (similar to 10%). A scanning electron microscopy investigation revealed that the carbonation process, as expected, significantly reduces porosity of RCA. The overall results show that if RCA is obtained by crushing of compact, high-quality concrete, the procedures of aggregate quality improvement are not necessary.", publisher = "Savez hemijskih inženjera, Beograd", journal = "Chemical Industry and Chemical Engineering Quarterly / CICEQ", title = "Influence of acid treatment and carbonation on the properties of recycled concrete aggregate", pages = "30-23", number = "1", volume = "24", doi = "10.2298/CICEQ161202014R" }
Radević, A., Despotović, I., Zakić, D., Orešković, M.,& Jevtić, D.. (2018). Influence of acid treatment and carbonation on the properties of recycled concrete aggregate. in Chemical Industry and Chemical Engineering Quarterly / CICEQ Savez hemijskih inženjera, Beograd., 24(1), 23-30. https://doi.org/10.2298/CICEQ161202014R
Radević A, Despotović I, Zakić D, Orešković M, Jevtić D. Influence of acid treatment and carbonation on the properties of recycled concrete aggregate. in Chemical Industry and Chemical Engineering Quarterly / CICEQ. 2018;24(1):23-30. doi:10.2298/CICEQ161202014R .
Radević, Aleksandar, Despotović, Iva, Zakić, Dimitrije, Orešković, Marko, Jevtić, Dragica, "Influence of acid treatment and carbonation on the properties of recycled concrete aggregate" in Chemical Industry and Chemical Engineering Quarterly / CICEQ, 24, no. 1 (2018):23-30, https://doi.org/10.2298/CICEQ161202014R . .