Slurry and Technology Optimization for Grouting Fissures in Earthen Sites with Quicklime

Abstract

Shrinkage differentiation and the need for multiple replenishments of slurry after fissure reinforcement are key problems for the grouting reinforcement of fissures in earthen sites. In this study, quicklime was mixed with 1.5% SH binder, clay, and fly ash in different proportions to prepare nine different mixtures and water-cement ratios of SH-(CaO + C + F) slurry. An expansibility test was performed, and based on the results, four groups of slurry were selected for a fluidity test. Ultimately, three different water-cement ratios were considered, and the mixing ratio of 3 : 2 : 5 was determined to produce the optimum slurry. The curing age was optimized according to the intensity and tensile and flexural strengths of the concretion. The selected slurry and curing age were then applied to testing traditional grouting technology and optimized grouting technology (i.e., microlime piles in the fissure) in fissure grouting field experiments. The acoustic wave, penetration resistance, and infrared thermal imaging results after fissure grouting were used to develop a preliminary explanation for the related mechanisms of slurry swelling, hardening, and lime pile compaction. The results showed that the combination of the preferred slurry and optimized grouting technology help address the problems of shrinkage differentiation on both sides of the fissure and need for multiple replenishments of the slurry after grouting.

Properties and Compatibility Assessment of the Slurry with Quicklime for Fissure Restoration of Earthen Sites in Northwest China

“…According to the previous related researches [7,8], a micro-expansion is caused when the mass proportion of quicklime reaches 30%. To ensure the appearance of the microexpansion, the mass proportion of quicklime adopts 30%, and the mass proportion of fly ash adopts 10%, 20% and 30%.…”

“…Some researchers suggest that adding quicklime to the slurry may reduce shrinkage [7]. Fissure grouting on site shows that no new cracks develop, and that the soil on both sides of the fissure is strengthened due to the slurry expansion when adding quicklime [8]. Now, it is essential that full-scale properties be tested and analyzed for further potential applications.…”

“…Unlike compatibility, incompatibility seems to be more easily approved by conservation workers. Some typical examples of incompatibility are that too much difference in strength leads to incompatible deformation, too much difference in color leads to a loss of historical information, and too much difference in gas/water permeability leads to interface separation [8], etc. This means that we can judge that the conservation material is incompatible with the exact relic when considering a certain character.…”

Preparation and Performance Investigation of Optimized Cement-Based Sealing Materials Based on the Response Surface Methodology

“…Besides, by analyzing the influence of different water–cement ratios and additive contents on the material properties, they determined the optimal material ratio that can lead to a reasonable fluidity and compressive strength. Cui et al 27 mixed raw lime, binder, clay, and fly ash at different ratios to prepare slurries with different water–cement ratios and material ratios. Moreover, they modified the water–cement ratio and material ratio in the fluidity test based on the results of the expansion optimization test.…”