Finite element simulation and experimental research on temperature stress of fast hardening concrete for bridge deck paving.

To study the temperature and stress variation laws of fast-hardening concrete for bridge deck paving,finite element simulation was employed to model the temperature and stress changes of fast-hardening concrete at different ages,and the results were compared and analyzed with the measured data from sensing optical cables to verify the accuracy of the finite element simulation. The results indicate that the temperature cracking index for all ages is greater than 1.5,and the tensile strength of fast-hardening concrete at 6 h can resist the tensile stress caused by hydration heat,possessing a certain crack resistance capability. For the fast-hardening concrete in bridge deck paving,the bottom layer,middle layer,and surface layer reach their peak temperatures approximately 4h after pouring,with the highest temperatures being 39,37,32,respectively,after which the temperature in each layer gradually decreases over time. Within the first 0 to 3d,as the age increases,the strain in the middle and bottom layers of the fast-hardening concrete for bridge deck paving gradually increases,reaching a peak at 3 d,then decreasing by 7 to 28 d. The finite element simulation calculations are basically consistent with the measured values,which can provide a reference for the crack prevention and construction process optimization of fast-hardening concrete in emergency repairs of large scale bridge deck pavement. [ABSTRACT FROM AUTHOR]