Study on mechanical properties and microstructure of the new grouting material

[摘要] The new grouting material with advantages of early strength, strong liquidity, better expansibility and environmental protection can be applied to underground structure engineering. The effects of different w/b ratios, curing ages, limes and SiO2 on the compressive strength of the new grouting material were investigated. By SEM and TGA-DSC analysis, its microscopic morphology and hydration products are explored. The results show that the early strength of the new grouting material develops rapidly, and the 3d compressive strength can reach 80% of the 28d compressive strength. Under the condition that the w/b ratio is 1.0, the compressive strength increases with CaO content in lime increasing. The addition of micron-SiO2 can improve compressive strength by about 5% when the formulation is reasonable. The main hydration products of SEM-EDS are needle-like ettringite, spherical aluminum gel and amorphous C-S-H(C-A-S-H) gel, corresponding to three endothermic peaks appearing in TGA-DSC at around 90°C, 230°C and 660 °C, respectively.

[发布机构] Jiangsu Key Laboratory Environment Impact and Structural Safety in Engineering, China University of Mining and Technology, Xuzhou; 221116, China^1;Jiangsu Collaborative Innovation Center for Building Energy Saving and Construct Technology, Xuzhou; 221116, China^2

[效力级别] 无线电电子学

[关键词] Early strength;Endothermic peaks;Ettringites;Grouting materials;Hydration products;Microscopic morphology;Needle-like;Properties and microstructures