Study on flexural behavior of concrete slabs strengthened with externally prestressed recycled bead wires

Abstract

Recycled bead wires were prestressed for reinforced concrete slabs using an innovative anchor that our research group created. In this work, four concrete slab groups were designed: three reinforced groups and one control group. In this work, four concrete slab groups: three reinforced groups, and one control group were designed. The reinforced slabs were subjected to controlled stretching stress of 720 MPa, 900 MPa, and 1080 MPa. Four-point bending static load experiments were performed to verify the recommended reinforcement method and assess the effect of different controlled stretching stress on slab bending performance. This paper presents an analysis of the bearing capacity, crack behaviour, stiffness, and ductility of the specimens. The superior tensile and flexural capabilities of recycled bead wires were used as external prestressing reinforcement materials, as evidenced by the results. The reinforced slab exhibited a maximum increase in ultimate bearing capacity of 142 %, resulting in a significant enhancement of its flexural bearing capacity. The overall stiffness of the slab was successfully increased using recycled bead wires, and the fractures of the reinforced slab exhibited characteristics of fine and dense material. The 'inverted arch' effect of prestressed steel wires efficiently controlled the breadth of the fracture, postponed the onset of cracks, and decreased the degree of specimen damage. The application of more controlled stretching stress was associated with higher carrying capacity, and this also better restricted the development and expansion of cracks. A numerical simulation of four sets of concrete slabs was conducted using ABAQUS, with a subsequent comparative analysis of the results obtained with those of the experimental tests. Furthermore, the feasibility of this type of reinforcement was also confirmed by theoretical analyses of ultimate load-carrying capacity and cracking deflection. Their low-carbon qualities can address issues with waste resources and create new concepts for recycled waste tires.