Untitled in english

Author(s)

Amanda Tafuri Costa

• Document type: Master's Dissertation
• Press: São Paulo.
• Institution: Universidade de São Paulo (USP). Escola Politécnica (EP/BC)
• Defense date: 2023-10-11

Examining board members

Antonio Domingues de Figueiredo; Daniel de Lima Araújo; Luísa Andréia Gachet

• Advisor: Antonio Domingues de Figueiredo; Luís Antônio Guimarães Bitencourt Júnior

Abstract

Materials such as concrete with recycled aggregate (RAC) are being studied due to the increasing need to the exploitation of natural resources and reduce the volume of construction and demolition waste disposed of in landfills. However, the recycled aggregates show a reduction in mechanical properties due to its higher porosity. In parallel, it is known that the use of this aggregate in steel fiber reinforced concrete (SFRC) does not represent such a significant reduction of the mechanical properties in the post-cracking condition; moreover, it can help to make feasible the use of RAC in specific applications. The parameterization of the behavior of steel fibers-reinforced recycled coarse aggregates concrete (SFRCAC), according to the recent criteria of design codes for structural purposes, has not been carried out yet. In this context, the study aims to characterize the RAC with different percentages of substitution of natural aggregates for recycled ones and different contents of steel fibers by means of flexion tests (EN 14651), axial compression, modulus of elasticity and specific mass. Furthermore, computational programs were used as a behavior extrapolation tool and their results were compared to the experimental ones. Finally, a full-size beam was designed for each fiber and aggregate replacement ratio in both the Ultimate Limit State (ULS) and Service Limit State (SLS). It was observed that the use of AR did not influence the SFRCAC structural element residual resistance when subjected to bending, even reducing the mechanical properties of the material, such as compressive strength and specific mass. The experimental and numerical results showed good correlation between them, both applied in a beam and showing that the SFRCAC presents design advantages for both ULS and SLS when compared to the reference concrete. (AU)

• FAPESP's process: 20/14186-2 - Characteriszation of steel fibre reinforced concrete with recycled coarse aggregate for structural application
• Grantee: Amanda Tafuri Costa
• Support Opportunities: Scholarships in Brazil - Master