Advanced Materials Research Vols. 255-260

Abstract: This paper describes an experimental study on the tensile capacity of post-installed rebars setting with adhesive. Eighty-one specimens containing single or double rebars were tested by an extraction tester to investigate the influence of embedment depth, edge distance and spacing of rebars on the tensile behavior of rebar system. The experimental results show that embedment depth is the most significant factor for rebar capacity and failure mode. The edge distance and the spacing effects are more significant only for the rebars with insufficient embedment depth. This study also attempts to evaluate two available design procedures provided by manufacturers. The comparison between the experimental data and predicted values calculated according to the two design procedures shows that both of the design approaches lay on the conservative side.

Abstract: Three perforated steel skeleton joints reinforced by a new method were tested under low cyclic load. The results indicated that the perforated steel skeleton and reinforced plate could work together well and the connection by weld all around of the reinforced plate with the perforated steel skeleton was effective. The test results proved the feasibility of the proposed method for the perforation and reinforcement of section steel, which provided a basis to the further study.

Abstract: The feasibility of two new methods to reinforce the perforated section steel column was verified by two groups of axial compression tests, each group contained two specimens. The test results showed that reinforcement plates and original steel skeleton can work together effectively before specimens overall yielded whether front fillet weld or weld all around was adopted for the connection of reinforcement plates with the steel skeleton. After most of the measuring points on reinforcement plates yielded, reinforcement plates by front fillet weld plumped outward and deformed rapidly; however, no notable deformation was found for the reinforcement plates by weld all around. From the load–displacement curves of the specimens , the yield load of the section steel column by weld all around was a little larger than that of section steel column by front fillet weld. In general, the connection of reinforcement plates with the steel skeleton by weld all around was better than that by front fillet weld.

Abstract: In consideration of the deficient study on dynamic response of reinforced concrete silos, especially group silos at home and abroad, taking the silos of one grain storage for instance, the dynamic response analysis of a single column-supported silo and that of group silos are carried out and contrasted through finite element method. Then the analysis results are contrasted with corresponding standards as well as academic studies.

Abstract: In order to study the bearing capacity conditions of the reinforced concrete structure in service in the phase of using,test the mechanical properties of the bending members of reinforced concrete structures under loading and not loading conditions,and compare and analyze the relationship of load and deflection, crack, steel strain,concrete face strain under the two conditions,has got the conclusion that the bearing capacity decreased almost 12% under holding load, and analyze the effect of the bearing capacity and deformation under holding load; use ABAQUS finite element to simulate bending members of reinforced concrete structures under holding loading,and the simulation values are very close to the experimental results; indicate that finite element simulation can be carried out in prediction the service life of reinforced concrete structure in practical engineering.

Abstract: In order to improve the accuracy of damage identification of offshore platform, structural damage identification method based on D-S evidence theory is proposed. Firstly, the stiffness matrix damage factor iterative method and modal strain energy method are used to identify the structural damage, and give the decision vectors respectively. Then, the decision vectors are imported into the D-S evidence theory formula, the damage probability of every element would be obtained and the damage location would be determined finally. Offshore platform model experiments show that the results of structural damage identification are more accurate and reliable after D-S evidence theory is used.

Abstract: This paper presents a study on the behavior of a damaged full scale unreinforced brick masonry building, retrofitted with ferrocement overlay and cement based grout injection, tested under cyclic loading. Damage mechanism and force-deformation behavior of the retrofitted structure are compared with its pre-damaged response to quantify the beneficial effects of retrofitting scheme. The lateral load capacity of the retrofitted building was significantly improved and the damage mechanism was transformed from mixed compression-flexural-shear mode to a more stable flexural rocking mode. The energy dissipation capacity, however, remained unchanged and the deformation capacity was slightly decreased.

Abstract: Aimed at the problems such as welding stress concentration and especially irregular distribution of welding residual stress for anchorage area in cable-stayed bridges, three full-scale beam-anchor-plate connection models of Chongqing Jiangjin Guanyinyan Yangtse Rive bridge were made and the tests were performed. The purposes of the tests and study were to investigate the distribution of welding residual stress in anchorage area and moreover to find a way to reduce and eliminate the welding residual tensile stresses. For this reason ultrasonic impact was imposed on the main welds of the three models. The result of the experiment showed that there were quite considerable welding residual stresses in the anchorage area. It also displayed that the ultrasonic impact was able to effectively decrease and even release the welding residual tensile stress. The ultrasonic impact was able to not only improve the adverse state of the welds stress but also make the distribution of the welds stress smoother. The ultrasonic impact is an effective and feasible method to decrease and eliminate welding residual stress and thereby improve the fatigue strength of welds for the steel bridge.

Abstract: The steel - concrete composite structure has many advantages in the field of reinforcement of bridge. But it is an important factor that whether the stud connector can make the components be firmly combined and make them work together. The research in this area has been not enough depth. The purpose of this study is to establish the design formula of stud in composite structure. Based on the conversion section theory, the strengthened part of composite structure is simplified into a kind of structure which is composed by only one kind of equivalent material and its physical property is similar to the original. In addition, the simplified model is gotten by mechanical analysis of the composite structures with steel plate and stud. Then through the application of elasticity theory method, the static equilibrium is carried out on the integrated structure and so the shear capacity in stud of connectors is gotten.

Abstract: Thin wall steel-concrete composite wall panels can be used as bearing member and also as maintenance structural plates, which can satisfy functional requirements of building including bearing capacity, heat insulation and preservation. The problem relating unilateral contact buckling of thin wall steel composite panels has received attention from many construction engineers. The investigation progress is analyzed in general and the investigation questions are illustrated. The research approach and technical routes of delaminated critical load are also presented.