Lin Liu, Kai Guo, Yingna Wang, and Jialun Zhang.Modeling Research on Cracking Mechanism and Stress Model of Early-Age Concrete with Embedded Heat Sources. Dynamic Systems and Applications 29 (2020) No. 6, 2275 – 2294

https://doi.org/10.46719/dsa20202968

ABSTRACT. Restrictions of concrete deformation at early stage will lead to complex stress state leading to early cracking, and all kinds of deformation are closely related to the change of temperature and moisture. Based on the thermo-hydro-mechanical coupling effect, a constitutive model of concrete with embedded heat source in early age was proposed in this paper. By comparing with the test of concrete columns with embedded heat sources in winter, the variation law of concrete stress field and the influencing factors of concrete cracking during curing were analyzed. The results show that the inner and outer restraints of concrete and the risk of cracking on the outer surface of concrete are increased when the power failure occurs in the heating belts; reducing thermal conductivity, increasing surface exothermic coefficient, reducing ambient temperature, lowering initial casting temperature, increasing heat source temperature, prolonging heating time and strengthening end restraint will increase the risk of concrete cracking; among them, strengthening end restraint, increasing heat source temperature and prolonging heat source heating time have the greatest impact on cracking risk. Therefore, it is very important to choose the appropriate design parameters, increase the initial casting temperature, strengthen the heat preservation effect, and select the reasonable heat source materials and heating time for the winter maintenance.

Key words: embedded heat sources; thermo-hydro-mechanical coupling, stress, concrete cracking.