纤维增强磷酸盐水泥基复合材料与旧混凝土的黏结性能试验研究

Magnesium phosphate cement (MPC), a new kind of inorganic cementing material, has some special performance such as rapid setting, fast hardening, and low drying shrinkage, etc. In order to apply the excellent performance of micro steel fiber reinforced phosphate cement matrix composites and carbon fiber fabric reinforced phosphate cement matrix composites to the repair and reinforcement of concrete structures, the double-sided shear performance of two MPC composite materials bonded with old concrete was studied, and the ultimate loads and failure modes were analyzed. Besides, the influence of three different interface treatments (roughing, grooving and bar planting) and different old concrete strength grades on the bonding properties were analyzed. The test results show that all three interface treatment methods can improve the bonding performance of the interface to varying degrees, among which the interface roughness treatment is the best, followed by grooving. Compared to the average value, the increases in shear strength for the bonding interface with the treatment of roughing, planting and grooving between the micro-steel fiber reinforced phosphate cement matrix composite material and the old concrete reach up to 284.31%, 196.08% and 250.98%, respectively. The increases in shear strength for the bonding interface with the treatment of roughing, planting and grooving between the carbon fiber fabric reinforced phosphate cement matrix composite material and the old concrete reach up to 306.38%, 195.74% and 221.28%, respectively.