Study On Preparation And Performance Of Environmental Protection And High Performance Reinforced Barrel Grouting

With the rapid development of China’s economy,prefabricated buildings have attracted the attention of the nation.In prefabricated buildings,the technology of reinforcing steel bar connection is the key factor affecting the safety of prefabricated concrete structures.At present,the most commonly used reinforcement connection is the sleeve grouting technology,so it is urgent to develop the environmentally friendly and excellent performance of the sleeve grouting material.In this topic,the alkali slag cement with water glass as the activator is selected as the cementing material to study the working performance of the water-binder ratio,alkali equivalent,plastic expansion agent,retarder,mineral admixture,mortar ratio to the sleeve grouting,The mechanical properties and the influence law of vertical expansion rate,and then using copper tailings to replace natural river sand as fine aggregate,combined with Dinger-Funk close-packing model theory,to optimize the raw material composition and ratio of sleeve grouting,to obtain a Environmentally friendly and economical sleeve grouting.The main research conclusions are as follows:（1）In this study,Na₂CO₃ is not suitable for retarding,and retarder Ba（NO₃）₂ can effectively prolong the setting time,combined with the test results of fluidity and compressive strength,the blending of retarder Ba（NO₃）₂ The amount of 0.5%～1.0%is more appropriate,and the setting time can be controlled at 49min～72min.（2）This paper mainly solves the early expansion performance through plastic expansion agent.When the amount of plastic expansion agent is 0.2%,the vertical expansion rate at 3h is 0.12%and the vertical expansion rate at 24h is 0.23%,which can ensure the early sleeve grouting.Micro-expansion performance,and small reduction in compressive strength.（3）This paper mainly improves the fluidity of sleeve grouting by adding fly ash floating beads.When the dosage is 0%～25%,the fluidity is 320mm～385mm.（4）Combining the tightest packing theory and method of Dinger and Funk equations,fly ash floating beads are used as mineral admixtures,and copper tailings sand is used to partially replace natural sand to increase the bulk density of the powder,and a sleeve grouting material with excellent performance is prepared.The mixing ratio is:12%fly ash,88%slag,1.1%sand-rubber ratio,13%copper tailings to replace sand,6%alkali equivalent,and 0.4%water-binder ratio.The initial fluidity of sleeve grouting material is340mm,30min fluidity is 280mm,1d compressive strength is 37.2MPa,3d compressive strength is 63MPa,28d compressive strength is 86.4MPa,and all properties meet the requirements of JG/T408-2019 standard specification.