Title: Rate-Sensitive Micromechanical Model for Concrete

Author(s): Oipankar Chandra and Theodor Krauthammer

Publication: Symposium Paper

Volume: 175

Issue:

Appears on pages(s): 281-292

Keywords: compressive strength; cracking (fracturing); damage; loads (forces); tests

DOI: 10.14359/5927

Date: 12/1/1998

Abstract:
A micromechanical damage model for concrete capable of taking into account the effect of highly time-varying load (time-varying stress) is outlined here. Giving primary consideration to concrete-type material, it is shown how an existing self-consistent rate-insensitive model can be modified and extended to induce rate dependency of concrete with pre-existing damage (cracks). The variations of several fracture mechanics parameters of concrete, viz., stress intensity factors, fracture toughnesses, etc., under the influence of high loading rates are investigated; the role of inertia of the material is explained and quantified. The process of crack evolution including crack kinking and nucleation under tensile and compressive stress-field has been thoroughly considered along with all possible situations that may arise. The resulting rate-sensitive model has been codified for high-speed computer and a few experiments have been replicated to validate it.