Abstract:

If the recycled components which are obtained from the old concrete members generated by precise demolition and appropriate treatment can be directly used in the structural members, it undoubtedly has significant material and energy-saving, and carbon-reduction effects. The relevant performance of the new members still needs to be quantitatively revealed and ascertained through systematic research. As a preliminary exploration, this paper investigated the flexural performance of precast concrete floor slabs containing recycled components. Bending experiments under sagging and hogging moment of this type of prefabricated floor slabs were carried out respectively. The influences of factors such as the surface treatment methods of recycled components and the strength difference between new and old concrete on the flexural performance under sagging and hogging moment of this type of prefabricated floor slab were investigated, as well as the influence of the construction methods of locally added connecting reinforcing bars on the flexural performance under hogging moment. The calculation methods for the flexural bearing capacities of this type of prefabricated floor slabs were proposed. The study shows that: (1) The flexural bearing capacity under sagging moment of this type of prefabricated floor slabs is significantly higher than that of the cast-in-place floor slabs; (2) The different surface treatment methods of the recycled components have a limited overall impact on the flexural bearing capacity under sagging moment. (3) Adding local connecting reinforcing bars at the ends of the recycled components can significantly enhance the flexural bearing capacity under hogging moment of this type of prefabricated floor slabs. (4) The results of the proposed methods for calculating flexural bearing capacities are generally conservative.

Key words: recycled components, precast floor slabs, flexural performance