A modified O-V-R constitutive relation for microcapsule self-healing concrete under uniaxial compression

Abstract Mechanical tests for microcapsule self-healing (MSH) concrete reveals that pore compaction process obviously exist in the stress–strain curves at undamaged regime, and temperature significantly affects healing efficiency. However, the typical Oucif-Voyiadjis-Rabczuk constitutive relation (simplified as ‘O-V-R formulation’) of MSH concrete ignored aforementioned aspects (Theor Appl Fract Mec 96:216-230, 2018). Herein, a modified O-V-R formulation is developed to address both pore compaction process and temperature effects. A logarithmic-law relation is utilized to consider pore compaction effects, and the temperature effects are regarded by modifying healing variable. A strategy is devised to quantitatively determine the constitutive parameters by least-square method for experimental curve. The modified formulation is first validated by comparing the identified parameters with the reference results, and then applied to predict the mechanical properties, indicating that both the strength and effective elasticity modulus apparently increase linearly within a certain temperature range from 20 °C to 60 °C. The work shows that the modified O-V-R formulation can effectively characterize the mechanical behavior of MSH concrete.