Chai Lijuan, Yue Zhonghua, Chen Zhichun, Fan Gaoyu, Wang Liuye
College of Civil Engineering, Taiyuan University of Technology, Taiyuan 030024, China.
School of Materials Science and Engineering, Southeast University, Nanjing 211189, China.
Materials (Basel). 2024 May 23;17(11):2522. doi: 10.3390/ma17112522.
To address the issue of pavement cracking due to brittle concrete in road and bridge engineering, this study explores the use of high-ductility magnesium phosphate cementitious concrete (HD-MPCC) for rapid repairs. The deformation and frost properties of HD-MPCC are analyzed to assess its suitability for this application. Deformation properties were tested for HD-MPCC specimens cured in both air and water. Subsequent tests focused on the frost performance and mechanical properties after freeze-thaw cycles. A mercury penetration technique was utilized to examine the pore structure. The findings reveal that the expansion deformation of HD-MPCC increases with curing age in both air and water conditions, and the quantitative relationship between the expansion deformation and curing age of HD-MPCC was analyzed. Additionally, the freeze-thaw cycles led to a decrease in mass loss, the relative dynamic elastic modulus, the ultimate tensile strength, the ultimate tensile strain, the flexural strength, and the peak deflection. The volume fraction of harmless and less harmful pores gradually decreased as the freeze-thaw cycle increased, while the volume fraction of more harmful pores increased, resulting in a decrease in the strength, ultimate tensile strain, and peak deflection.
为解决道路桥梁工程中脆性混凝土导致的路面开裂问题，本研究探索使用高延性磷酸镁水泥基混凝土（HD-MPCC）进行快速修复。分析了HD-MPCC的变形和抗冻性能，以评估其在此应用中的适用性。对在空气中和水中养护的HD-MPCC试件进行了变形性能测试。后续试验重点关注冻融循环后的抗冻性能和力学性能。采用压汞法检测孔隙结构。结果表明，HD-MPCC在空气和水条件下的膨胀变形均随养护龄期增加，分析了HD-MPCC膨胀变形与养护龄期之间的定量关系。此外，冻融循环导致质量损失、相对动弹模量、极限抗拉强度、极限拉应变、抗弯强度和峰值挠度降低。随着冻融循环次数增加，无害和危害较小孔隙的体积分数逐渐降低，而危害较大孔隙的体积分数增加，导致强度、极限拉应变和峰值挠度降低。
