Zhou Yingwu, Zhuang Jiahao, Lin Wenwei, Xu Wenzhuo, Hu Rui
Guangdong Provincial Key Laboratory of Durability for Marine Civil Engineering, Shenzhen University, Shenzhen 518060, China.
Materials (Basel). 2024 Apr 19;17(8):1904. doi: 10.3390/ma17081904.
The poor performance of recycled concrete aggregate (RCA) leads to greater creep in recycled aggregate concrete (RAC) compared to natural aggregate concrete (NAC). To enhance the quality of RCA, this paper utilizes a 2% concentration of a nano-SiO (NS) solution for pre-soaking RCA. This study aims to replace natural aggregate (NA) with NS-modified recycled aggregate (SRCA) and investigate the creep and shrinkage properties of NS-modified recycled aggregate concrete (SRAC) at various SRCA replacement rates. Subsequently, the creep and shrinkage strains of NAC, SRAC, and RAC are simulated using the finite element method. Finally, a comparative analysis is conducted with the predicted creep and shrinkage strains from CEB-FIP, ACI, B3, and GL2000 models. The experimental results indicate that the creep and shrinkage deformation of SRAC increases with the SRCA replacement rate. Compared to NAC, the creep and shrinkage deformation of SRAC at replacement rates of 30%, 50%, 70%, and 100% increased by 2%, 7%, 13%, and 30%, respectively. However, when 100% of the natural aggregate is replaced with SRCA, the creep and shrinkage deformation decreases by 7% compared to RAC. Moreover, the CEB-FIP and ACI models can predict the creep and shrinkage deformation of concrete reasonably well.
与天然骨料混凝土（NAC）相比，再生混凝土骨料（RCA）性能较差，导致再生骨料混凝土（RAC）的徐变更大。为提高RCA的质量，本文采用浓度为2%的纳米SiO₂（NS）溶液对RCA进行预浸泡。本研究旨在用NS改性再生骨料（SRCA）替代天然骨料（NA），并研究不同SRCA替代率下NS改性再生骨料混凝土（SRAC）的徐变和收缩性能。随后，采用有限元方法模拟了NAC、SRAC和RAC的徐变和收缩应变。最后，与CEB - FIP、ACI、B3和GL2000模型预测的徐变和收缩应变进行了对比分析。试验结果表明，SRAC的徐变和收缩变形随SRCA替代率的增加而增大。与NAC相比，SRCA替代率为30%、50%、70%和100%时，SRAC的徐变和收缩变形分别增加了2%、7%、13%和30%。然而，当100%的天然骨料被SRCA替代时，与RAC相比，徐变和收缩变形减小了7%。此外，CEB - FIP和ACI模型能够较好地预测混凝土的徐变和收缩变形。
