Abstract

Utilizing recycled concrete powder (RCP) as a partial precursor for alkali-activated slag (AAS) is conducive to digesting construction waste and promoting the sustainable development of AAS. However, the AAS containing RCP (AASR) generally exhibits poor properties due to the low reactivity and porous microstructure of RCP. To address this issue, this study utilized tannic acid (TA), an eco-friendly plant polyphenol, to functionalize RCP and improve its quality. This process could be achieved simply by soaking RCP in TA solutions with low concentrations for one hour. Results showed that the reaction between TA and RCP could produce Ca-TA complexes to fill the pores and cracks in the RCP particles, improving the flowability of the produced AASR mortar. Additionally, the TA molecule could induce the formation of denser hydration products around RCP particles by capturing Ca2+, which strengthened the interface between RCP particles and paste, and significantly reduced the porosity of the produced mortar. As a result, the proposed functionalization method achieved a 41.4 % increase in the 28d compressive strength of the AASR mortar made with pristine RCP. Furthermore, this method enhanced the eco-efficiency of the produced mortar by up to 28.2 % and the cost-benefit by up to 41.6 %.

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.