Papers by Keyword: Walls

Abstract: The present work deals with numerical simulations concerning the international benchmark “Vulcain tests on 3 Walls” regarding fire tests conducted in CSTB in Paris, France. To this aim, sequentially-coupled thermo-mechanical analyses have been performed on three reinforced concrete walls, characterized by different load levels and boundary conditions. The numerical results show that the imposed compressive load and boundary conditions significantly influence the magnitude of the displacements. In the case of simply supported walls, the wall with the lower load level exhibited a gradual and monotonic increase of the displacements at mid-height (both in the tests and in the numerical analyses), while the wall with the higher load level exhibited a displacement reversal due to second-order effects after approximately 60 minutes of fire exposure. This reversal, which was obtained in the analyses, was not observed in the test. Load bearing capacity of all the three specimen walls was maintained in such a way that the collapse did not take place during two hours of fire exposure.

Abstract: Thermal insulation exterior wall coating has been successfully prepared, using styrene-acrylic emulsion as film former, and xonotlite as heat-insulating filler, which produced by hydrothermal reaction. The insulation mechanism of xonotlite is explored, through analyzing the microstructure of homemade xonotlite thermal insulation exterior wall coating. The results show that xonotlite is a kind of compound type heat-insulating filler that can effectively weakened the heat transfer in the coating, like heat conduction, thermal convection and thermal radiation.

Abstract: Urban structure is constantly changing. Its development was influenced by several important steps in history of any city. Up to interval of time, it is possible to accept the assessment of the pros and cons, but mainly emerging lessons for the future. When studying the map sources, the authors of the article found three main groups. These groups have got common working title barriers of the cities. For the single barriers of the cities were chosen the specific examples of urban structures on which the effects of their influence were demonstrated. On the basis of the influence of the three groups of barriers were defined two basic structures of the cities.

Abstract: This paper studies the effect of lamination and fiber orientation on the geometrically nonlinear dynamic response of debonded regions in walls strengthened with FRP. The paper adopts an analytical/numerical approach and uses a specially tailored finite element formulation for the layered structure. By means of this analytical/numerical tool, two strengthening layouts for a wall segment subjected to a dynamic shear loading are compared. In the first layout, the fibers are oriented along the width and height of the segment and in the second one, they are oriented along its diagonals. The analysis reveals that the two layouts are involved with significantly different critical points and significantly different dynamic post-buckling behaviors. Specifically, it shows that the diagonal layout, which better serves the shear loading scenario, is involved with a much smaller critical displacement and a dynamic post-buckling behavior that is governed by the stiffer compressed and tensed diagonals.

Abstract: Building wall plays a key role in the noise isolation. As a there are lot of open holes in the wall for various construction equipments, pipes and lines, it is an important issue how to determine the maximum area of wall cracks with the given expect sound insulation. The calculation model is established with immune algorithm, the expected value of the sound isolation is defined as objective function, the areal density, thickness and Young modulus of monolayer wall are defined as bounded variable. The global maximum value of objective function is obtained by the MATLAB program and so to determine the materials, thickness and construction details which reach to the sound insulation.

Abstract: Through the vibration table testing, with the pine furniture model, the distance between the model and wall, as well as the experimental load and acceleration as the main research parameter. Research on the following aspects: (1) the effect of interaction on distance between the furniture and the wall of the influence of the interaction, (2) the interaction between furniture sliding, mobile and the wall, and the relationship between the test load frequency, acceleration, etc, (3) influence of furniture size on furniture sliding, mobile, etc. The results revealed that sliding volume increases as the frequency decreases significantly after the model collides with the wall; when the frequency increases, the movement of the monomer decreases. When the furniture is apart from the walls in a certain distance, the collision between them is prevented, and the movement of the models which collides the object is as twice as the movement the single one.