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To provide the most effective comprehensive performance grouting material ratio, in this experimental investigation, a total of eight grouted specimens with two water-cement ratios (0.45:1, 0.55:1) and four different superfine cement contents (0%, 30%, 70%, 100%) were evaluated. Based on a uniaxial compression test, the fractal dimension of the fragments, a mercury injection test, and scanning electron microscopy, the effects of the superfine cement content on the strength characteristics and microscopic characteristics of the grouted specimens were studied. The results showed that increasing the superfine cement content could enhance the compressive and tensile strength of the grouted specimens and reduce the fractal dimension of the fragments and the porosity of the grouted specimens. The superfine cement content increased from 0% to 70% when the water-cement ratio was 0.45:1. The compressive strength of the grouted specimens increased from 16.7 MPa to 26.3 MPa, and the fractal dimension decreased from 1.8645 to 1.2301. When the water-cement ratio was 0.55:1, the compressive strength of the grouted specimens increased from 10.5 MPa to 20.6 MPa, and the fractal dimension value decreased from 2.2955 to 1.4458. When the superfine cement content increased from 0% to 100%, the water-cement ratio was 0.45:1. The porosity of the grouted specimens was reduced from 28.41% to 21.62%. When the water-cement ratio was 0.55:1, the porosity of the grouted specimens was reduced from 33.33% to 29.46%.
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http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8588491 | PMC |
http://dx.doi.org/10.3390/ma14216709 | DOI Listing |
Materials (Basel)
August 2025
Shandong Key Laboratory of Civil Engineering Disaster Prevention and Mitigation, Shandong University of Science and Technology, Qingdao 266590, China.
The increasing depth of coal mine construction has led to complex geological conditions involving high ground stress and elevated groundwater levels, presenting new challenges for water-sealing technologies in rock microfissure grouting. This study investigates ultrafine cement grouting in microfissures through systematic analysis of slurry properties and grouting simulations. Through systematic analysis of ultrafine cement grout performance across water-cement (W/C) ratios, this study establishes optimal injectable mix proportions.
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July 2025
Faculty of Mechanical Engineering and Robotics, AGH University of Krakow, Mickiewicza 30 Av., 30-059 Kraków, Poland.
Corrosion-related failures have emerged as a critical driver of premature support bolt failures in underground mines, emphasizing the urgency of understanding the phenomenon with respect to enhancing safety in underground environments. This study investigated key factors influencing bolt degradation through extensive experimental evaluation of cable bolts in simulated underground bolt environments. Multi-stranded cable specimens were exposed to saturated clay, coal, mine water, and grout/cement environments.
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August 2025
Department of Civil Engineering, Higher Future Institute of Engineering and Technology in Mansoura, Mansoura, Egypt.
The rising demand for sustainable concrete stems from resource scarcity, environmental concerns, and structural performance needs. Preplaced Aggregate Concrete (PAC) improves durability and efficiency but requires alternative binders to lessen dependence on Portland cement. This study explores the formulation of a sustainable geopolymer grout, incorporating red clay, slag, and fly ash, to address these concerns while promoting the reutilization of industrial by-products.
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August 2025
College of Safety Science and Engineering, Xi'an University of Science and Technology, Xi'an, 710054, PR China.
The leakage of borehole during CBM drainage leads to a significant decrease in concentration, severely restricting the effectiveness of gas drainage in the coal seam. After grouting in the gas pre-drainage boreholes, the slurry around the borehole forms a grout-graded composite structure with the broken coal, and its permeability is a key factor affecting the sealing. Triaxial seepage tests of the composite specimen were conducted with different degrees of fragmentation and moisture content to investigate its permeability.
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July 2025
Collaborative Innovation Center for Efficient Utilization of Water Resources, North China University of Water Resources and Electric Power, Zhengzhou, 450046, China.
Pea-gravel grouting (PGG) is a composite material backfilled between segment and surrounding rock of a shield tunnel, requiring balanced mechanical properties and impermeability. However, the practice always faces an issue of the defects of harden PGG with local cavity, less dense or insufficient strength. In this paper, an experimental study was firstly carried out on the grouting slurry to determine its mix proportion by evaluating the workability and density, which showed that the rational w/b = 0.
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