Rate‐dependent model of structural concrete incorporating kinematics of ambient water subjected to high‐cycle loads

Purpose The paper aims to propose a rate‐dependent model of structural concrete in combination with the kinematics of condensed water. Design/methodology/approach First, the paper proposes the coupling model of water versus cracked concrete with a mathematical completeness of equilibrium and deformational compatibility. The proposed model deals with anisotropy of structural performance and of permeability, which is a particular issue of concrete caused by cracks. The governing equation for saturated concrete in this study is based on Biot's theory that deals with particle assembly as a two‐phase composite. Second, the paper shows the possible reduction of the fatigue life of real‐scale bridge RC decks owing to the water residing in structural cracks under moving wheel‐type loading. Findings The paper shows that the existence of water possibly has an influence on the rate‐dependency of structural performance. The comparison of transition of pore pressure and principal strain indicates that damage to the concrete skeleton is accelerated by internal stress caused by high pore pressure. It suggests that the existence of water can reduce the fatigue life of bridge decks, especially when the upper layer is saturated. Originality/value This paper clarifies the effect of pore water on structural concrete by using numerical model considering kinematics of water.