Welcome to Visit BULLETIN OF THE CHINESE CERAMIC SOCIETY! Today is

BULLETIN OF THE CHINESE CERAMIC SOCIETY ›› 2025, Vol. 44 ›› Issue (5): 1834-1840.DOI: 10.16552/j.cnki.issn1001-1625.2024.1206

• Solid Waste and Eco-Materials • Previous Articles     Next Articles

Performance Evaluation of Wet Carbonization Recycled Sand Powder and Formation Mechanism of Early Strength of Cement Paste

LIU Chenchen1, XIE Xiangbing2, LI Guanghui2,3, SIMA Xiaoqing1, ZHANG Yilin1, SI Bin2, SHAO Jinggan4   

  1. 1. School of Materials Science and Engineering, Zhengzhou University of Aeronautics, Zhengzhou 450046, China;
    2. School of Civil Engineering and Environment, Zhengzhou University of Aeronautics, Zhengzhou 450046, China;
    3. Henan Vocational College of Water Conservancy and Environment, Zhengzhou 450008, China;
    4. Henan Jiaotong Institute Engineering Technology Group Co., Ltd., Zhengzhou 450046, China
  • Received:2024-10-12 Revised:2024-12-16 Published:2025-05-20

Abstract: The low efficiency of dry carbonization for recycled concrete sand powder (RCSP) limits the utilization of RCSP resources. In this paper, the effects of wet carbonization treatment on the properties of RCSP and the influence of RCSP on the hydration and properties of cement paste at different replacement ratios were investigated. The results show that the CaCO3 content in the wet carbonization recycled sand powder (WRCSP) is as high as 77.06% (mass fraction), and the CO2 sequestration amount amounts to 0.53 kg CO2 absorbed by each kilogram of RCSP. When the replacement ratio of WRCSP is 20% (mass fraction), 7 d compressive strength of cement paste is 45.3 MPa, showing increases of 76.3% and 4.61% compared to RCSP and PC, respectively. The main carbonization products of WRCSP are polycrystalline calcium carbonate and high polymerization silica gel, which can react with the hydration products of the cement, accelerate the early hydration of the cement, and significantly enhance the early mechanical properties of the cement. In summary, the higher the carbon fixation capacity after wet carbonization treatment is, the better the performance of WRCSP as a substitute for cement is. This conclusion verifies the feasibility of wet carbonization of RCSP and provide reference for future industrial applications.

Key words: recycled concrete sand powder, wet carbonization, carbonization product, mechanical property, silica gel

CLC Number: