Yu Zhijie, Liu Shujie, Zhang Jiwei, He Wen, Tian Qinghao, Tian Le, Sun Jinze
China Coal Research Institute, Beijing 100013, China.
National Engineering Research Center of Deep Shaft Construction, Beijing 100013, China.
Materials (Basel). 2024 Jul 22;17(14):3620. doi: 10.3390/ma17143620.
Polycarboxylate superplasticizers BMC-L and BMC-S were utilized as modifiers in the formulation of novel cement-based grouting materials. Indoor tests were conducted on 32 groups of cement slurries, varying by water-cement ratio (0.5:1 and 0.6:1) and modifier content (0, 2‱, 4‱, 6‱, 8‱, 10‱, 12‱, and 14‱), to test their density, funnel viscosity, water separation rate, and stone rate. Four groups of slurry modified with BMC-L were selected as the preferred slurry, and the apparent viscosity test, uniaxial, and triaxial compression test of the slurry stone body were conducted. The study investigated the influence of BMC-L on various properties of the slurry, including its apparent viscosity, uniaxial compressive strength, stress-strain relationships, shear strength parameters, and elastic modulus. Ultimately, the pore structure and phase composition of the slurry stone body were detected by Nuclear Magnetic Resonance (NMR) and X-ray Diffraction (XRD), and the impact of BMC-L on slurry performance was examined from a microstructural perspective. Results indicate that the two polycarboxylate superplasticizers exert minimal influence on the density and water separation rate of the slurry. Within the effective incorporation range of the polycarboxylate superplasticizer, increasing the dosage correlates with a decrease in both the stone rate and viscosity of the slurry. BMC-L significantly enhances the mechanical properties of the slurry stone body by promoting more complete cement hydration and reducing porosity. The uniaxial compressive strength of slurry stone body with a 6 ‱ BMC-L dosage reached 29.7 MPa after 7 days and 38.5 MPa after 28 days of curing, representing increases of 118.4% and 64%, respectively, compared to masonry with 0 BMC-L dosage. The shear strength parameters and elastic modulus of the slurry stone body also showed corresponding increases.
聚羧酸系高效减水剂BMC-L和BMC-S被用作新型水泥基灌浆材料配方中的改性剂。对32组水泥浆体进行了室内试验，这些水泥浆体的水灰比（0.5:1和0.6:1）和改性剂含量（0、2‱、4‱、6‱、8‱、10‱、12‱和14‱）各不相同，以测试其密度、漏斗粘度、泌水率和结石率。选取四组用BMC-L改性的浆体作为优选浆体，并对浆体结石体进行表观粘度试验、单轴和三轴压缩试验。该研究调查了BMC-L对浆体各种性能的影响，包括其表观粘度、单轴抗压强度、应力-应变关系、抗剪强度参数和弹性模量。最终，通过核磁共振（NMR）和X射线衍射（XRD）检测了浆体结石体的孔隙结构和相组成，并从微观结构角度研究了BMC-L对浆体性能的影响。结果表明，这两种聚羧酸系高效减水剂对浆体的密度和泌水率影响极小。在聚羧酸系高效减水剂的有效掺入范围内，增加用量与浆体结石率和粘度的降低相关。BMC-L通过促进水泥更完全水化和降低孔隙率，显著提高了浆体结石体的力学性能。BMC-L用量为6‱的浆体结石体在养护7天后单轴抗压强度达到29.7MPa，养护28天后达到38.5MPa，与BMC-L用量为0的浆体相比，分别提高了118.4%和64%。浆体结石体的抗剪强度参数和弹性模量也有相应提高。
