Banca de DEFESA: Layane Silva Souza

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
STUDENT : Layane Silva Souza
DATE: 20/07/2023
TIME: 14:00
LOCAL: Online (Plataforma Teams)
TITLE:

Bending behavior of steel fiber-reinforced concrete composite slabs with fiber-reinforced polymer permanent formwork

KEY WORDS:

Glass Fiber-Reinforced Polymer (GFRP); Steel Fiber-Reinforced Self-Compacting Concrete (SFRSCC); Stay-in-Place formwork; Composite Structures; Composite Slabs

PAGES: 105
BIG AREA: Engenharias
AREA: Engenharia Civil
SUBÁREA: Estruturas
SPECIALTY: Estruturas de Concreto
SUMMARY:

The structures with permanent formwork made of composite materials have gained prominence in the civil construction industry in recent years due to their resistance to corrosion, high load capacity, low density, fatigue resistance, and ease of handling. However, despite the growth of research in this field, being a new method, there are challenges to be overcome and a scarcity of available experimental data. In this work, an innovative system of composite slabs was proposed, consisting of a permanent formwork made of Fiber-Reinforced Polymer (FRP) and Steel Fiber-Reinforced Self-Compacting Concrete (SFRSCC). The proposed component has a trapezoidal cross-section and serves a dual function in the composite slab, acting as formwork in the initial stage and reinforcement in service conditions. On the other hand, SFRSCC was chosen to replace the traditional reinforcement used to counteract the effects of shrinkage, usually consisting of welded steel mesh. The choice of SFRSCC is also due to its inherent properties, allowing for productivity gains in the construction process, and the hypothesis that the use of fiber-reinforced concrete may confer a more ductile behavior to the structural element, which will be verified in the tests carried out. The work was carried out according to the following steps: 1) development of an analytical model and preliminary design of the slabs; 2) production of permanent FRP formworks; 3) characterization of FRP; 4) production of composite slabs; 5) characterization of SFRSCC; 6) four-point bending tests; and 7) analysis of the results. The analytical model was based on NBR 8800, ACI 440.R, and ACI 440.2R, disregarding the tensile strength of the concrete and the compressive strength of the polymer. The production of formworks was divided between the manufacture of flat sheets and the manufacture of trapezoidal sheets, carried out using the vacuum infusion method. Subsequently, they were characterized through direct tensile tests. After the characterization of FRP, the production of composite slabs was carried out, applying a sand treatment to the surface of the permanent FRP formwork. The characterization of the concrete was carried out after a period of 28 days, and the behavior of the composite slab was determined through four-point bending tests for a clear span of 1800 mm. In total, two types of composite slabs were analyzed, with the main parameter being the variation in the thickness of the permanent formwork through the concentration of unidirectional fibers used. The flexural behavior of the composite slab revealed a predominant mode of failure by bending, with significant displacements and pseudo-ductile behavior. The slabs demonstrated effective composite action, with linear behavior up to the initial detachment load of the formwork, influenced by its thickness. Slabs with thicker sheets showed lower detachment loads and displacements. The study demonstrates that the proposed composite slab exhibits suitable structural behavior and has potential for application in the civil construction industry.

COMMITTEE MEMBERS:
Presidente - 1550512 - RODRIGO DE MELO LAMEIRAS
Interno - 1111740 - GUILHERME SANTANA ALENCAR
Externa à Instituição - GLAUCIA MARIA DALFRE - UFSCAR