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Title |
Damage of Overlaid Concrete Structures Subjected In Thermally Transient Condition by Rainfall
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Keywords |
보수체; 열 충격; 비선형 응력-변형률 곡선; 변형률 연화특성; 경계면의 연직인장파괴; overlaid concrete structures; temperature shock; non linear stress-strain relationship; strain-softening; peel-off |
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Abstract |
The failure phenomenon of overlaid concrete structures, such as surface crack and peel-off failure in the contact zone, was investigated due to temperature shock(rainfall). To investigate this failure phenomenon, the surface tensile stress, and the shear stress, the vertical tensile stress in the contact zone were analysed using the non-linear stress-strain relationship of material such as strain-hardening- and strain-softening diagrams. Rainfall intensity, overlay thickness and overlay material were the main variables in the analyses. It is assumed that the initial temperature of overlaid concrete structures was heated up to 55℃ by the solar heat. With a rain temperature 10℃ and the rainfall intensity of nR=1/a, tR=10min, 60min, the stress states of overlaid concrete structures were calculated. The result shows that only fictitious cracks occurred in the overlay surface and no shear bond failure occurred in the contact zone. The vortical tensile stress increasing with overlay thickness was proved to be the cause of peel-off failure in the contact zone. The formulae for relationship between the vertical tensile stress and overlay thickness, material properties were derived. Using this formulae, it is possible to select proper material and overlay thickness to prevent failure in the contact zone due to temperature shock caused by rainfall.
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