Preparation of Reinforcement Coupler Grouting Material Based on the Orthogonal Design

Due to escalating labor costs and the conclusion of the demographic dividend in China, prefabricated construction has rapidly advanced, with coupler grouting material playing a pivotal role in these structures. The optimal Ordinary Portland Cement (OPC) to Sulphoaluminate Cement (SAC) mass ratio of 9:1 was established for the material of grouting by formulating the material of grouting through combined use of OPC and SAC in a mass ratio of 9:1 and assessing the composite’s strength, fluidity, and setting time. Subsequent controlled experiments determined the optimal water-to-binder and binder-to-sand ratios to be 0.26 and 1:1, respectively. Using orthogonal experimental design, the ideal mix of mineral additives was identified. A detailed range and variance analysis determined the optimal mass ratios: 3% silica fume, 7% slag powder, and 5% fly ash. Further experimentation with polycarboxylate water-reducer, organosilicon defoamer, and UEA expanding agent in single admixture trials led to the selection of the most effective dosages: water-reducer at 0.3%, defoamer at 0.05%, and UEA expanding agent between 0.03% and 0.05%, meeting the standard requirements for grouting materials.