Applied Mechanics and Materials Vols. 193-194

Abstract: Abstract : A series of standard fire-resistance tests were carried out to study the fire performance, failure modes and fire-resistance ratings of glulam beams. The test results showed that these glulam beams performed well during the tests, and the fire-resistance rating requirements can be achieved as expected. The study has provided necessary knowledge and experimental data for the determination of fire-resistance performance of glulam beams in the fire code of China.

Abstract: To study the mechanisms and effects of atactic polypropylene (APP) modified asphalt felt preventing crack, which is used as interlayer between old cement concrete pavement and asphalt overlay, authors carried through the tests of level tension, field road, and direct shearing. A new test-bed machine, named level tension for interlayer, was developed, and its mechanical composition and work principle were also set forth. Using the new machine, level tension tests were conducted with APP modified asphalt felt as interlayer materials, which indicated that the test-bed has favorable mechanical behaviors and the felt has better performance to prevent cracks than any other materials. APP modified asphalt felt was applied to field road, moreover, its favorable interlayer bonding and working performances were proved by field drill cores. The direct shear tests accounted that the shearing destruction displacement comes to 7.5mm, 3.0mm more than that without the specific interlayer, with the cores from the road. The test results showed that APP modified asphalt felt has good road service performances, with evident effect of anti-cracking when it is used as an interlayer material between asphalt overlay and old cement concrete pavement.

Abstract: By deeply analyzing and studying the physical and chemical properties of Lueyang’s basalt fiber, its characteristics such as the chemical components, the crystallization’s upper limit temperature and lower limit temperature during the melting process, and the the viscosity and temperature change during melting process are verified to provide theoretical bases for the industrial production of a new type composite materials, and meanwhile to offer grounds for the development of a new generation of composite fiber materials.

Abstract: Through the introduction of the Structure of compounded raw soil walls , this paper has a deep research on the adobe block which is the main innovative components of the wall. With the help of the traditional Rammed earth theory and large quantities of practical data, we have gained some scientific data and specific sizes of the adobe block in practical production to further improve the construction art of the ecological walls, providing the reference for the Structure of compounded raw soil walls in practical application.

Abstract: The porous materials are more and more popular throughout the world. However most of the resent researches focus on the porous materials applying to horizontal plane. In this paper an experiment was conducted to study the applicability of porous decorative layer applying to vertical walls. The Experimental result shows that the wet porous decorative layer has a good applicability to west-facing wall by reducing the external surface temperature at least 8°C and eliminating the temperature peak of inner surface. The equivalent thermal resistance of the porous decorative layer is 0.40 m2•K/W, when using the 4-day value of the measurement. In the summer of Guangzhou, the porous decorative layer on west-facing wall is recommended to supply water once a day at 13:00.

Abstract: The actual stress state of high filled culvert was not accurately reflected by the calculation method of earth pressure in the prevailing Chinese General Code for Design of Highway Bridges and Culverts. So the vertical earth pressure characteristics of different culvert structural style under fill-load were studied based on field temperature and FEM numerical analysis. Meanwhile, the key influencing factors, such as the height of culvert fill, and boundary condition on the earth pressure characteristics were also discussed. It is shown that the distributions of vertical earth pressure on the middle culvert top and culvert flank wall, as well as culvert side are all nonlinear, they are different from the results calculated by the code method under the high fill load. The influence of the factors on the stress state of high filled culvert should be comprehensively considered. The results can give some references on the design and construction procedure.

Abstract: This paper introduce the innovative application of finite element method in bridge-deck pavement on curved slope. Based upon Xi’an-Hanzhong Expressway in Qinling Mountains, the developed combination of FE models, including the overall and sub-model, study loading response of bridge-deck pavement on curved slope, and relate the mechanical analysis to structural parameters.

Abstract: For analysis of prestressed concrete wall vibration character of cylindrical LNG tank on conditions of inner-tank leaking, the finite element analysis model of tank exterior wall of leak conditions is built and the modal analysis is carried out; then dynamic pressure on liquid storage equivalent with tank wall have the same acceleration of additional mass, natural frequency of teak wall is gotten; in state of semifluid and fluid filled, using methods of simulation of prestressed effect equivalent load, the natural frequency of the external wall of the central to the wave curve is achieved. The analyzing results show that: in state of fluid filled LNG storage tank, liquid is the largest effect on the frequency of prestressed concrete external wall. When liquid position is less than half the maximum reservoir depth, its natural frequency can be calculated by empty tank; when the liquid position is more than half the maximum reservoir depth, we should considerate that the liquid vibration has impact the vibration frequency of tank exterior wall; when different liquid position, the largest affection is 2.29% to natural frequency of prestressed wall.

Abstract: This paper analyzes mainly that the CFRP reinforced concrete research and FRP cloth reinforced characteristics and advantages, and from the material aspects illustrate the CFRP cloth’s faults. For different components, materials, and the nonlinear programming and analysis, through the integral, combination, discrete type three calculation model of material and materials between, namely, concrete, steel, concrete and reinforced, GFRP cloth, concrete and CFRP cloth the constitutive relation analysis, this paper expounds the present research, points out the existing limitations of the present study and later the research direction. Finally, the paper draw the conclusion that the column and beam mechanical strength, toughness, and crack resistance, impact resistant properties and durability of these aspects to illustrate the superiority of the CFRP reinforced concrete. That fiber reinforced polymer (FRP) strengthening, repairing concrete has broad prospects for development.

Abstract: The problem of rock and soil structure has long been a major concern in the field of soil mechanics theory. Some literatures have made preliminary discussions of stable static soil structure. The structural and morphological diversity & complexity of rock and soil which is composed of large number of granules have been extensively recognized. We still only have a vague idea of the properties of rock and soil body with different structure and morphology. To further understand the effect of structure and morphology of rock and soil body on its properties, we established a unit cell orthogonal model. The properties of soil body under this structure and morphology were analyzed; the pattern of changes in some major performance parameters, especially in the presence of pores with different morphologies, was discussed. Analysis of unit cell orthogonal model indicated that the structural performance of rock and soil material was mainly affected by porosity, pore distribution, morphology and directionality. The related variation patterns are summarized as follows. The greater the pore area (volume) was, the greater its impact on structural performance would be; the impact of pore distribution relied on pore size. At a fixed porosity, the more scattered the pores were, i.e. the greater the number of pores was, the larger the pore surface area was, and the greater its impact on structural performance (stiffness) would be; on the contrary, the smaller the number of pores was, i.e. the more concentrated the pores were, the greater the soil stiffness would be. These results of analysis agreed well with our past experiences.