Investigating the pore size characteristics and mechanical properties of the stone bodies formed by residual grout is crucial for understanding the authentic permeability and load-bearing capacity of grouting materials after being scoured by water flow. In this study, the pore size distribution, porosity, uniaxial compressive strength (UCS), and elastic modulus (E) of stone bodies formed by residual grout from polyacrylate latex-modified cement grouting material (PLMC) were systematically investigated, and pure cement grout (PC) as a control group. First, scouring tests were conducted on grouting materials with various water-to-cement ratios (w/c, 0.6–0.8) and polymer-cement ratios (p/c, 0–0.2) under different flow velocities (0–1 m/s). Subsequently, the pore size characteristics of stone bodies formed by residual grout under various conditions were studied via nuclear magnetic resonance test. Finally, the uniaxial compression tests were conducted to investigate the impact of water scouring on the mechanical properties of grouting materials, and the relationship between pore size characteristics and macro mechanical responses was analyzed. Results show that the stone bodies formed by residual grout compared to the non-scoured state develop mesopores and macropores, and the number of micropores also increased significantly. This porosity escalation results in a reduction in UCS and E. When the flow velocity reaches 1 m/s, the porosity of PLMC with w/c = 0.8 increases by 2.95 %, while UCS decreases by 14.6 % and E decreases by 37.4 %. PC demonstrates more pronounced changes, with a porosity increase of 7.01 %, UCS decreases by 32.9 %, and E decreases by 41.5 %. With the rise in w/c, the deterioration of pore structure and mechanical properties of the stone bodies formed by residual grout is more significant compared to the non-scoured state. Increasing p/c can mitigate the deterioration of the pore structure and mechanical properties. The findings provide meaningful guidance for the grouting reinforcement under dynamic water conditions.

中文翻译：

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流水冲刷灌浆材料的孔径特性和力学性能研究


研究残余灌浆形成的石体的孔径特性和力学性能，对于了解灌浆材料经水流冲刷后的真实渗透性和承载能力至关重要。本研究以纯水泥浆料 （PC） 为对照组，系统研究了聚丙烯酸酯乳胶改性水泥注浆料 （PLMC） 残余浆料形成的石体孔径分布、孔隙率、单轴抗压强度 （UCS） 和弹性模量 （E）。首先，在不同流速 （0–1 m/s） 下，对具有不同水灰比 （w/c， 0.6–0.8） 和聚合物灰比 （p/c， 0–0.2） 的灌浆材料进行冲刷测试。随后，通过核磁共振试验研究了残余浆液在不同条件下形成的石体的孔径特征。最后，进行单轴压缩试验，研究水冲刷对灌浆材料力学性能的影响，并分析孔径特性与宏观力学响应之间的关系。结果表明，与未冲刷状态相比，残余灌浆形成的石体发展出中孔和大孔，微孔的数量也显著增加。这种孔隙率增加导致 UCS 和 E 减少。当流速达到 1 m/s 时，w/c = 0.8 的 PLMC 孔隙率增加了 2.95 %，而 UCS 降低了 14.6 %，E 降低了 37.4 %。PC 表现出更明显的变化，孔隙率增加了 7.01 %，UCS 降低了 32.9 %，E 降低了 41.5 %。 随着 w/c 的增加，残余浆料形成的石体孔隙结构和力学性能的劣化比非冲刷状态更为明显。增加 p/c 可以减轻孔隙结构和机械性能的恶化。研究结果为动态水条件下的注浆加固提供了有意义的指导。