Papers by Keyword: Long-Term Behavior

Abstract: Questions arise whether construction delay combined with construction method modification of a long-span bridge will affect bridge resistance to withstand the working load in the long term. A continuous bridge with a span of 78 m - 145 m - 77 m that crosses a large river has experienced this condition. In its implementation, there was a difference in construction time compared to the initial design. As a result, it is necessary to conduct an analysis of the effects of the difference in construction time on the bridge structure. An analysis of the stages of bridge construction was carried out using the Midas Civil program to determine the stress and deflection that occurred. Stress and deflection over a long period of time were calculated to determine the effect of construction methods and delays.

Abstract: In Korean residential building, wall – piloti structures have been frequently used in the ground floor. For cost-effective design, a new wall – piloti structure where the walls are directly connected with the columns without transfer girder was suggested in the previous study. In this study, the proposed structure was applied to actual residential building. To verify the structure safety, structural monitoring and long-term behavior prediction was carried out. Strain gauge and displacement meters was installed to measure the strain of re-bars and the deflection of slab. During the construction period, in all wall – piloti structures, compressive strain was less than the allowable strain and relative deflection of slab satisfied the serviceability criteria. Further, in the long-term behavior, the maximum vertical strains of the re-bar were less than allowable strain under the service load condition.

Abstract: Lime plaster modified with pozzolana based on calcined kaoline mixed with mudstone and reference lime plaster are studied in the paper. For the studied materials, determination of bulk density, matrix density and total open porosity is done first. Then, specific attention is paid to the assessment of moisture diffusivity and chloride diffusion coefficient that are considered as decisive parameters for the materials’ durability. The measured data are used as input parameters for computational modeling of studied materials’ performance using computer code TRANSMAT 6.2 based on finite element computer simulation tool. On the basis of measured and calculated results, the applicability of newly developed plaster for renewal of historical buildings is discussed.

Abstract: It is well known that shear lag effect exists in wide flange concrete slabs. Traditionally, the effective flange width method is employed for considering the shear lag effect in a steel/concrete composite beam. The limitation of this method is that the load types and constraint conditions are generally ignored. In this paper, an analytical method using full flange width has been proposed by introducing shear warping shape function and intensity function of the shear warping displacement. By mean of two unknown functions: the vertical displacement of the whole cross section and the intensity of the warping, a variational balance condition which involves equilibrium equations with relevant boundary condition is imposed by the virtual work theorem. As a result, the shear-lag effect is considered by additional virtual external load, expressed as “additional bending moment”. The performance of this method dealing with elastic problem has been verified by finite element method using solid elements. Finally, the method is applied to investigate the long-term behavior of a beam fixed at two ends. It has been found that the results yielded from the code based on the effective flange width method are intervenient between those obtained from the current model with elastic and viscoelastic problem; the result errors of beam finite element model considering shear-lag effect can be modified by the method proposed in this paper.