Modification Effects of Nano-CaCO₃ on Engineering Performance of Cement Grouts

Abstract

Efficacy of added nano-CaCO3 (NC) on engineering performances, including fluidity, initial setting time, bleeding rate and yield stress of cement grouts was investigated in this study. Results showed that the fluidity and bleeding rate for NC-cement (NCC) composite grout first decreased with increased NC content (i.e., ratio of NC mass to cement mass) and then slightly recovered as the NC content exceeded 2%. The initial setting time was always reduced while the yield stress increased with increased NC content. The microstructure of NCC was analyzed by means of scanning electron microscopy (SEM) and X-ray diffraction (XRD). It was found that the NC can promote the cement hydration, but an excess amount of NC will inhibit the cement hydration and affect the engineering performances of cement grouts. The optimum NC content for modification of cement grouts was thus 2%.

The Effects of Different Nanoadditives on the Physical and Mechanical Properties of Similar Silty Mudstone Materials

“…At present, the appropriate amount of nanoadditives in the existing materials can effectively improve the relevant physical and mechanical parameters of the materials, formulate mixed materials suitable for different needs, and increase the scope of the original materials [9][10][11][12][13][14]. In terms of improving the cement substrate, Wang et al found that adding nano-CaCO 3 into Portland cement can significantly improve the mechanical properties of cement-based materials and make the cement substrate more uniform.…”

High-Fluidization, Early Strength Cement Grouting Material Enhanced by Nano-SiO2: Formula and Mechanisms

“…In previous studies [ 15 , 18 ], nano-SiO 2 can also play a significant role in early strength at the curing age of 7 days for common cement-based materials. In contrast, the effect of nano-SiO 2 weakened at the curing age of 3 days and disappeared at the curing age of 7 days for the HCGA proposed in this study.…”

“…Feng et al [ 17 ] proved the significance of nano-SiO 2 on the early age hydration of cement mortars. Qiu et al [ 18 ] revealed the modification effects of nano-CaCO 3 on the engineering performance of cement grouts. Jiao et al [ 19 ] proved the feasibility of nano-Fe 3 O 4 used in cement paste.…”