Material Performance and Structural Design of Low-Shrinkage and Non-Steam-Cured UHPC Overlay for Bridge Deck Pavement
To reduce the shrinkage deformation and curing costs of UHPC(Ultra-High Performance Concrete),a low-shrinkage,non-steam-cured UHPC was developed using porous CB(Calcined Baux-ite)aggregate as an internal curing material.Mechanical and deformation properties of the UHPC were tested and evaluated through laboratory experiments.Finite element numerical simulations were employed to analyze the early temperature and humidity stress evolution in the UHPC overlay of a bridge deck pavement.The results indicate that the developed UHPC maintains its ultra-high strength under non-steam curing conditions,with a compressive strength of 154 MPa and a splitting tensile strength of 19.3 MPa at 28 d.The shrinkage deformation of UHPC containing CB aggregate is only 160 μm/m at 28 d,effectively reducing the risk of warping and delamination between the UHPC pave-ment layer and the underlying concrete.Moreover,UHPC exhibits superior abrasion resistance and im-pact resistance compared to ordinary concrete,thereby extending the service life of the bridge deck pavement.Numerical calculation results show that the maximum tensile stress in the UHPC overlay is minimally influenced by the thickness and length of the pavement layer,eliminating the need for the installation of expansion joints.To enhance the bond performance between the UHPC overlay and the base course,the surface of the concrete base course should be roughened(exposing aggregate),and reinforing bars should be installed between the base course and the UHPC overlay according to the design.This study validates the feasibility of using self-developed UHPC as a concrete bridge deck overlay.
UHPC(Ultra-High Performance Concrete)bridge deck pavementlow shrinkagenon-steam curingearly age stress
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