EXPERIMENTAL RESEARCH ON MECHANICS OF LONG-SPAN AND HEAVY-LOAD PRESTRESSED CONCRETE DOUBLE-TEES

In order to further expand the application range of long-span prestressed double-tees, a prestressed double-tees was designed, it can withstand a live load of 30 kN/m², and it was applied to an experimental office building project. Through the static load test of full size double-tees, the deformation characteristics, crack development law, bearing capacity of normal section and inclined section of the double-tees were obtained, and the mechanical properties of double-tees could meet the use requirements of heavy-load floor and the feasibility of calculation method was verified. The results showed that the prestressed double-tees had a suitable bearing capacity at middle span section and shear bearing capacity of dapped end, and the crack resistance coefficient and deflection of the component could meet the requirements of relevant codes and design; the truss reinforcement set on the double-tees rib top further enhanced the cooperative effect performance of the cast-in-place surface layer and the precast part. There was no cracking of the cast-in-place layer and the precast part during the test. The reasonable construction measures were proposed, which could effectively avoid the generation of cracks in rib plate top and dapped end in the production and construction process of double-tees, and having the value of practice.