Mix ratio optimization and comprehensive performances of novel high-early strength non-shrinkage sleeve grouting material

Considerable infrastructures for urban renewal need fast assembly and daylight open traffic, and it is urgent to develop a novel sleeve grouting material with high-early strength and non-shrinkage (UCGM) for fast connection of assembly structure. Here, sulphoaluminate-Portland cement (S+PC) and high-strength sulphoaluminate clinker and anhydrite (7SA+AH) were used as two binders of UCGMs. The close packing effect of various particle size of dry powders of UCGM was achieved with the closest packing theory. Then, the preliminary mix ratio optimization of UCGM was carried out according to the initial flowability (S0) and 12 h compressive strength (fc12 h) of UCGM. Finally, the mix ratio of UCGM was optimized by further introducing additives and fibers, and the rheological property, mechanical property, expansion rate, durability, and microstructure of UCGMs were comprehensively studied. Results show that, the S0, flowability retention after 30 min (S30 m), fc12 h, 28d compressive strength (fc28d), 3 h expansion rate (P3 h), and the gap between 3 h/24 h expansion rate (GP3–24 h) of UCGM with S+PC and 7SA+AH system are 300 mm, 270 mm, 62 MPa, 128.4 MPa, 0.06%, 0.095%; 300 mm, 280 mm, 82.5 MPa, 106 MPa, 0.025%, 0.11%, respectively. Obviously, the UCGM with S+PC system has superior flowability, faster and longer lasting growth in strength, higher durability, and better in-packing effect for sleeve structure, which is more suitable for fast assembly of urban facilities.