Numerical Simulation On Mechanical Behavior Of Cement Concrete Pavement Slab At Early-age

Cement concrete pavement construction as early as age stage mechanical behavior is complex, and adverse environment, structure, material composition can result in early cracking of concrete. At the same time, according to latest research at home and abroad, pavement plate initial curing properties have a significant impact on their service stage mechanical behavior and failure modes. Therefore, to carry out in-depth study of cement concrete pavement early age behavior is very important to improve the pavement performance.Based on temperature field numerical simulation research in the early cement concrete pavement early age,we carry out mechanical behavior numerical simulation and field test study of single block pavement plate in early age period, specific as follows:Contrast choose linear elastic model, thermoelastic model and curing creep mod-el, incremental method derived the stress-strain incremental form of the road slab earl y-age mechanical behavior, obtaining the weak form of the finite element method by combining with the principle of virtual work. Produce a finite element program by us-ing Fortran software, the results were compared and combined with ABAQUS softwa re.Effects can be considered the real-time transform of road slab internal temperature, environment meteorological parameters, boundary conditions, weight, age and creep on the road slab early age mechanical behavior of the program characteristics.Cement concrete pavement early age mechanical behavior of early-age properties and parameter sensitivity analysis found:the vertical displacement of the plate angle increase gradually with age, plate displacement amplitude is not obvious, but the board in the daytime temperature phase will have a convex shape warping slab disengaging phenomenon.The comprehensive effect of principal stress and stress distribution and warping shape, restriction of gravity, temperature deformation and the bottom support interface. The coefficient of thermal expansion coefficient, tensile creep parameters, interfacial tension stiffness are significant factors influence the absolute vertical displacement values of pavement in early age; tensile creep parameters are significant factors of principal stress effect of pavement in early age, followed by the elastic modulus, coefficient of thermal expansion, compressive creep parameters, road panel structure size and interfacial tension stiffness.Different construction season panel of early-age theoretical study shows: different seasons for constructing the panel in curing temperature differences.In this paper, under typical conditions in different seasons as early as 7:00 paved road before 4 days the maximum warping displacement in summer (264.6μm), spring (123.3μm), autumn (29.13μm), winter (8.961 μm). The maximum principal stress in the plate in summer (0.36MPa), spring(0.15MPa), autumn(0.07MPa), winter (0.01MPa). Paving time had significant influence on cement concrete pavement early age mechanical behavior.Field test research found that:the vertical displacement values of panel which is constructed in the winter are very low,24 hours after pouring (final 12 hours) within the first day of each position basically is at the expansion stage, early because the board high internal temperature led to the initial vertical expansion displacement is bigger than plate angle. Observed the early age of panel strain and temperature reversal phenomenon similar to the foreign literature. Comparison of the numerical simulation show that the simulation of temperature field is reasonable and stress trend is the same.The theoretical analysis and field test show that, the early age behavior of pavement in addition to the effect of environment temperature, but also by the curing temperature, hydration reaction, gravity, creep and the deformation of plate shape and internal stress strain coordination, character expression is very different from the mature of cement concrete pavement.