Planar Crack Approach to Evaluate the Flexural Strength of Fiber-Reinforced Concrete Sections.

Autor: Carmona JR; Escuela Técnica Superior de Arquitectura de Madrid (ETSAM), Universidad Politécnica de Madrid (UPM), 28040 Madrid, Spain., Cortés-Buitrago R; Escuela Técnica Superior de Arquitectura de Madrid (ETSAM), Universidad Politécnica de Madrid (UPM), 28040 Madrid, Spain., Rey-Rey J; Escuela Técnica Superior de Arquitectura de A Coruña, Universidad de A Coruña (UDC), 15071 A Coruña, Spain., Ruiz G; E.T.S.I. Caminos, Canales y Puertos, Universidad de Castilla-La Mancha (UCLM), 13001 Ciudad Real, Spain.
Jazyk: angličtina
Zdroj: Materials (Basel, Switzerland) [Materials (Basel)] 2022 Aug 24; Vol. 15 (17). Date of Electronic Publication: 2022 Aug 24.
DOI: 10.3390/ma15175821
Abstrakt: This article describes a model based on concepts of Fracture Mechanics to evaluate the flexural strength of fiber-reinforced concrete (FRC) sections. The model covers the need by structural engineers to have tools that allow, in a simple way, the designing of FRC sections and avoiding complex calculations through finite elements. It consists of an analytical method that models FRC post-cracking behavior with a cohesive linear softening law ( σ - w ). We use a compatibility equation based on the planar crack hypothesis, i.e., the assumption that the crack surfaces remain plane throughout the fracture process, which was recently proven true using digital image correlation. Non-cracked concrete bulk follows a stress-strain law ( σ - ε ) combined with the Bernoulli-Navier assumption. We define a brittleness number derived from non-dimensional analyses, which includes the beam size and the softening characteristics. We show that this parameter is key to determining the FRC flexural strength, characterizing fiber-reinforced concrete, and reproducing the size-effect of sections in flexure. Moreover, we propose an expression to calculate the flexural strength of FRC as a function of the cited brittleness number. The model also gives the ratio between the residual strength in service conditions and the flexural strength. Model results show a good agreement with tests in the scientific literature. Finally, we also analyze the brittle-ductile transition in FRC sections.
Databáze: MEDLINE
Externí odkaz:
Nepřihlášeným uživatelům se plný text nezobrazuje