Papers by Author: Qiang Fu

Abstract: Reactive Powder Concrete (RPC) has excellent properties such as high toughness and high durability. In this paper, based on the experimental research of the different unbonded prestressed tendons of the unbonded partially prestressed RPC beams, the crack calculation of prestressed RPC beams is analyzed. The results show that the crack regulation is special in some extent of the unbonded partially prestressed RPC beams. It is suggested that the crack width of unbonded partially prestressed RPC beams calculated in accordance with the specification for unbounded partially prestressed concrete structure should multiply the reduction factor of 0.7.

Abstract: The unbonded prestressed concrete slabs is usually used in big span high-rise buildings. Due to the existence of stairs, elevators, piping shafts and washroom etc，（hole drilling is usually encountered in the floor of unbonded prestressed concrete structures）, which weakens the rigidity of concrete slab, and it has different influences on the slabs with openings in different locations. Based on the contrast experiments of the unbonded prestressed concrete slab with openings in different locations subjected to uniform load, this thesis investigates and analyzes mechanical behavior of the unbonded prestressed concrete slabs with openings in different locations (central，around edge and corner) subjected to uniform load. Using the yield-line theory to calculate the ultimate bearing capacity of pre-stressed slabs with openings, and comparing from experimental results to theoretical ones, this paper puts forward some conclusions of how different opening locations impact the ultimate bearing capacity of pre-stressed slabs with openings

Abstract: Based on the bending experiment for two-span continuous beams of retard-bonded prestress concrete, the analysis of the stress increment of prestressed tendons is made in the loading process. The theory that the working performance of retard-bonded prestressed concrete members is as same as unbonded prestressed concrete members during the retarding period is demonstrated. It is feasible to use the formulas for the reference (Technical specification for concrete structures prestressed with unbonded tendons) to calculate σ_puthe ultimate stress and Δσ_p the Stress increment of the retard-bonded prestressed tendons and the recommended formulas are advised to use. It is also demonstrated that retard-bonded prestressed concrete members have the same working performance as bonded prestressed concrete members after the retarding period. The conclusion of this paper can provide the reference date for the design of retard-bonded prestressed concrete continuous beam.

Abstract: Based on the contrast experiments of unbonded prestressed concrete slabs with openings subjected to uniform load strengthened by different methods, this paper investigates and analyzes the appearance and the development of cracks, deflections, bearing capacity of the unbonded prestressed concrete slabs that are with strengthening steel and with hidden beams. According to the experimental failure mode of the slabs, prestressed concrete slabs with openings by yield line theory considering the conditions to enhance the contribution of hidden beam and the strengthening steel. Compared with the experimental data, this paper puts forward some bearing capacity lift-off effect of the slabs under different strengthened methods.

Abstract: Owing to the outstanding advantages of unbonded prestressed technology, it has been widely used in high-rise building floor. However, with the continuous improvement of the function requirements of the building, the boards with openings become more and more common, not only in new constructions but also in renovation projects. These holes will change the mechanical properties of the original floor, and cause stress concentration around the holes easily. This article carries on the simulation analysis by modeling the experimental model using ANSYS software, focuses on the deflection, crack and ultimate load of unbonded post-tensioned prestressed concrete board with open-hole (under uniform load in tensioning and loading stage). After making the comparative analyses to the mechanical behavior and failure mechanism under the different locations of the holes, the simulation results are compared with experimental results, shows that ANSYS can simulate the whole process of loading better, provides theoretical basis for its application and promotion in practical engineering.