A continuous composite girder bridge with a steel-concrete composite deck has the advantage of structural rationality, economical efficiency and construction period. In this study, static loading tests were carried out to investigate the crack behavior of the composite deck under hogging bending moment around the intermediate support of continuous girder. Regarding the evaluation of crack width, we took three factors into consideration; tension-stiffening effect, the state of crack and the influence of bottom plate. Our test results show that these factors have influence on the crack width of composite deck. Finally, we would like to propose a method for evaluating crack width of composite deck in continuous composite girder.

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In Japan, as so many highway bridges constructed in the last four decades are superannuated, the maintenance of these bridges has become the most serious problem to extend their service lives with appropriate rehabilitation works. In concerning with bridge slabs, replacement of severely deteriorated slabs is a recent trend to minimize the LCC. The authors have developed a rationalized joint for precast steel concrete composite decks that can shorten the construction period by reducing the joint width accompanying with decrease of concrete volume and placing re-bars. In this paper, through wheel running fatigue tests for the joints, the characteristics of concrete cracks, progress of vertical displacement and applicability for actual bridges, have been discussed and confirmed.

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The steel plate-concrete composite slab has an issue of management and maintenance. because that slab has a steel plate on the bottom therefore it is hard to check cracks in the inner concrete by visual observation. Accordingly, the Japan Bridge Association adopts the stiffness evaluation method which is based on deflection. This report indicates making high precision stiffness evaluation possible through results of three type method tests. The first is the result of deflection by using IIS which is developed as a FWD for slab by Tokyo Metropolitan Government. The second is the result of using FWD and the sensor system of IIS. The third is result of the static loading test by using a load truck. Those three tests were implemented at Yoroi Bridge which has composite slabs and has been used for 24 years.

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This study examines the evaluation of damage of real reinforced concrete (RC) slabs using impact vibration examination and dynamic deflection measurement. The rigidity of the RC slabs on the bridges of the expressway is evaluated by the impact vibration examination. The damage level of the RC slabs is evaluated by the deflection measurement. The distributed load is reversely analyzed by the static FEM analysis based on these result, and the rigidity evaluation technique to the RC slabs to which the impact vibration examination was not executed is examined.

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It could be guess that existing slabs at the highway bridge are given damages and bad influences on fatigue durability by increasing chopping by exchanging the expansion joint repeated several times. Besides, the thinner attaching portions under expansion joints are, the weaker the fatigue durability of slab is.
This report is a result of examination of life prolongation under wheel running fatigue test by using the specimen which is the strengthen slab by CFRP bonding method, and it has three different type expansion joints (rubber joint, asphalt pavement buried joint, and CFRP buried joint).

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This study evaluates the fatigue resistance of RC slabs with the deteriorated top surface reinforced by overlaying the SFRC. As a result, the number of equivalent cycles for reinforced RC slabs is obtained by adding the equation of a D-N curve, the reduction factor of concrete and the reduction factor for design standards to the number of equivalent cycles for RC slabs, which is obtained from a fatigue test under running wheel loading, and the fatigue resistance of the reinforced RC slabs is evaluated. The equation of the S-N curve is proposed for the reinforced RC slabs designed in accordance with the 1964 and 1968 design standards, with the top surface reinforced by overlaying the SFRC.

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In cold, snowy reginons, the surface concrete of RC deck slabs sufferrs from progressive deterioration and damage, thereby detractiong from traffic safety. In light of this, there is a call for a low-cost method of repairing the upper surface of RC deck slabs that affords life-cycle extention in cold , snowy regions. The repair method should be applicable to both cold, snowy environments and non-cold, non-snowy environments, and it should be able to secure the required fatigue durability and load-bearing capacity as determined by wheel-load running tests. This study reports the first-phase test. Using a scale model of an RC slab deck, the test was made under a non-cold/non-snowy environment. Our proposed repair methods for 10-to-30-mm-deep deck deterioration were evaluated by fatigue durability test using a wheel running tester.

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This study evaluates the effect of reinforcement and the fatigue resistance of RC slabs with the top surface applied with an adhesive in dry and wet conditions and overlaid with the SFRC, assuming the cutting the top surface using a water jet and the site in rainy conditions before the reinforcing work. As a result, the separation between the top surface and the SFRC is not seen until deflections of up to 1/400 of the span, L. In addition, the fatigue resistance in terms of the number of equivalent cycles of RC slabs with the top surface applied with an adhesive in wet conditions is higher than or comparable to those in dry conditions.

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The study verifies the effect of compressive strength of concrete on the fatigue resistance of the CFS- and CFSS-reinforced RC slabs. The results of a comparison of the number of equivalent cycles between the CFS- and CFSS-reinforced RC slab test specimens obtained from a fatigue test indicate that the CFSS-reinforced RC slab has 1.2-1.3 times greater effect of reinforcement than the CFS-reinforced RC slab. The study also reveals that the fatigue resistance of the CFS- and CFSS-reinforced RC slabs is ensured when the compressive strength of concrete is not lower than the specified design strength prescribed in the Specifications for Highway Bridges but is not ensured when the compressive strength of concrete is lower than the specified design strength, although the effect of reinforcement is secured.

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The objective of this study is to estimate the fatigue durability of a light-weight RC slab strengthened with PVA short-fiber. In this paper, a fatigue durability of this strengthened light-weight RC slab was tested under a wheel loading test. Influences of PVA short-fiber and light-weight aggregates on the punching shear strength were discussed. As a result, it was suggested to be able to evaluate the punching shear strength of RC slabs in consideration of these influences. A fatigue life of this strengthened light-weight RC slab was roughly consistent with the S-N curve that was calculated using this proposed method of the punching shear strength.

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