Resumo

RODELO, Ramón; RODRIGUEZ, Mario E.  e  RESTREPO, José I.. Relevant parameters of the stress-deformation curve in compression of unconfined concrets produced in Mexico. Ing. sísm [online]. 2020, n.103, pp.18-36.  Epub 02-Fev-2021. ISSN 0185-092X.  https://doi.org/10.18867/ris.103.534.

The seismic design standard for the city of Mexico prescribes the use of no-lineal analyses, for which it is necessary to define, among various others, the parameters of the unconfined concrete stress-strain relationship. This study describes results of analytical and experimental studies of unconfined concrete produced in Mexico. Based on experimental test data obtained in this study, recommendations for estimating parameters that define the unconfined concrete stress-strain curve are given. Test of concrete cylinders were conducted at the Instituto de Ingeniería (Institute of Engineering), UNAM, México, following testing procedures according to national and international standards. and taking average results of tested samples. In this research, expressions for determining the modulus of elasticity E c , are given. Parameter E c is relevant for computing lateral displacements of structures subjected to earthquake actions, as well as for computing periods of vibration of these structures. It is also presented expressions to define other important parameters of the concrete stress-strain curve, which are considered when modeling plastic hinges in nonlinear analysis. Such parameters are the strain at the stress f’ c of unconfined concrete specimen, ε’ c , and the ratio of E c to the secant modulus E sec . Recommendations are given for estimating these parameters for concrete produced in Mexico.

Palavras-chave : Concrete; compressive stress; modulus of elasticity; secant modulus; compressive stress-strain curve; density of concrete measure.