Properties Study On The Steel Bar/Wire Mesh Preplaced Aggregate Concrete Composite Strengthening Method In Concrete Square Column Reinforcement

Ferrocement reinforced steel bars has high-strength, crack resisting, permeability, durability, applications in wide range, and many other superior properties, which is gradually aroused widespread interest and concern. In order to maintain its advantage in the concrete structure repair and reinforcement, this paper attempts to introduce Preplaced Aggregate Concrete, and proposes a structural strengthening method combining the concepts of preplaced aggregate concrete (PAC) and steel wire mesh mortar strengthening.SWPAC not only preserves the advantages similar to the ferrocement reinforced steel bars, but also overcomes the bar too close or too many layers of steel mesh laid, through the pressure of wiping or spraying mortar is difficult to achieve density, difficult to guarantee the quality and disadvantage of low efficiency in construction. Comparison to the enlarging section method(reinforcement layer thickness≥60mm), without excessive increase in the member section of the premise (reinforced layer thickness is about 50mm or so), it uses large diameter steel (8 ~ 14mm) to ensure the reinforcement ratio, thereby substantially increase the bearing capacity of the reinforced members; on the other hand,pre-filling 15~25mm coarse aggregate in the placed steel cage, and then grouting in the high-pressure, the formation of Prepacked Aggregate Concrete-steel wire reinforced mortar Layer integrated with high strength, high stiffness, low shrinkage, high adhesion, ductility and durability and many other advantages.As the first step in the systematic study, this paper carried out PAC infusion of mortar mix and the basic performance test, PAC grouting test, and 11 columns concrete columns reinforced with SWPAC comparative study. Experimental study, the perfusion liquid mortar, high strength and low shrinkage component reinforcement to meet regulatory requirements; PAC grouting process, the perfusion pressure, speed and filling height are a factor in quality control of grouting, construction technology to be further improved to make the construction of a higher degree of operational and mechanization; SWPAC method was not reinforced with ordinary casting, thick liquid reinforcement and increased the section method were compared with experimental research and the use of different reinforcement ratio and different stirrup and different ways reinforced stirrup connected component of axial compression tests.The results showed that, SWPAC method not only could guarantee the quality of reinforcement construction to substantially increase the capacity to be reinforced members, stiffness and ductility, but also reinforced members show good overall performance.