Fracture properties of rubberized concrete under different temperature and humidity conditions based on digital image correlation technique

Rubberized concrete is a kind of environmentally friendly construction material. Application of waste rubbers in concretes by replacing traditional aggregates has high feasibility for the recycling materials. However, the fracture properties of rubberized concrete will be influenced greatly because of the low adhesive properties between the cement paste and rubber particle. In this study, the effects of temperature and humidity on the fracture performance of rubber concrete were studied by three-point bending test. The digital image correlation technique was used to study the cracking and fracture properties of the rubberized concrete under different temperature and humidity conditions. The results indicated that Mode I was the main fracture failure mode of the rubberized concrete. The maximum width of the fracture process zone (FPZ) and crack width of the beam specimen in the rubberized concrete were similar to those in ordinary concrete. The width of the FPZ was approximately half of the maximum aggregate diameter. The crack width of the rubberized concrete specimen linearly decreased with height. The temperature and humidity has remarkable influence on fracture properties of rubberized concrete. With an increase in ambient temperature, the fracture toughness and fracture energy of the rubberized concrete initially increased gradually, and then decreased. The fracture toughness and fracture energy of the rubberized concrete slightly increased with the increment in ambient humidity. The technique of digital image correlation has advantages in measuring fracture parameters of rubberized concrete, and the results obtained from this study can greatly promote the further application of rubberized concrete. (C) 2020 Elsevier Ltd. All rights reserved.