Optimal formulation design of polymer-modified cement based grouting material for loose deposits

•A polymer-modified cement grout material for grouting in loose deposits was proposed.•The effects of the composition on the response variables were investigated by RSM.•The optimal formulation was determined using a multiobjective optimization technique. Due to material requirements for grouting in loose deposits, a new polymer-modified cement grout (PMCG) material was designed by addicting polyethylene glycol (PEG), polycarboxylate superplasticizer (PS) and sodium silicate into the cement grout. Then, the properties of PMCG were predicted statistically by using the response surface method (RSM) and the effects of the four parameters (w/c, PEG content, sodium silicate content and PS content) as well as their interaction on the response variables (fluidity, bleeding rate, gel time, and early strength) were investigated. Furthermore, the optimal formulation of PMCG (w/c of 0.9, 8.7% sodium silicate, 4% PEG and 1% PS) can be obtained using a multi-objective optimization technique considering the multi-performance requirements of grouting material in loose deposit. Finally, the macro-performance of the grouting material formed by optimal formulation was validated by a set of experiments. The results demonstrated that the proposed designing method can work effectively in determining the optimal formulation of the grouting material to meet various engineering demands.