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To study the effect of SAP incorporation on the early shrinkage of SAP internally cured concrete with the aim to solve the problems of early shrinkage and cracking of bridge leveling-layer concrete, using the SAP incorporation method as a parameter, the mechanical properties test of internally cured concrete, the shrinkage performance test of ring restraint and the scanning electron microscope observation test were carried out. The effects of the SAP content and incorporation method on the flowability, mechanical properties, shrinkage performance and microstructure of internally cured concrete were analyzed. The experimental results show that when the content of the SAP in concrete is 0.2% of the mass of cementitious materials, it has the least influence on the compressive strength of concrete. The addition of preabsorbed water to the SAP can delay early cement hydration, increase the later cement hydration rate and final hydration degree, and improve the concrete strength. Preabsorbed water mixed with an SAP can effectively improve the shrinkage of concrete, and the shrinkage reduction effect is more obvious than that from the dry addition of the SAP; the early cracking risk of concrete without an SAP is high, and it will crack before day 28. The addition of an SAP can strengthen the microstructure of concrete and improve its density and crack resistance, effectively avoiding concrete cracking. It is recommended that the water-absorbent resin be incorporated in a preabsorbent manner, and the SAP preabsorbent ratio is equal to the maximum water storage rate of the SAP.

Rutting is one of the most challenging and important distresses in steel deck pavement. The prediction of rutting depth is considered to be one of the most complex issues in pavement engineering. In this study, a large piece of linear track accelerated loading facility MLS66 was used to conduct the test on rutting at temperature 60℃. To predict the behaviors of steel deck pavement, three-dimension FE model of the bridge is used in simulation. The time-hardening version of power-law model is used to investigate the rutting behaviors of steel deck pavement. A uniaxial compression creep test was applied to research on the creep characteristics of two adopted paving materials at temperature 60℃. According to the test results, the nonlinear curve fitting software of OriginPro 8.0 is used to obtain the creep parameters based on power law creep model. Then, immediate and statistical loading is adopted for FE prediction instead of moving loading. Comparisons of the FE prediction with the results of full-scale testing have been presented, and fairly good results have been obtained.

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