Applied Mechanics and Materials Vols. 291-294

Abstract: This paper investigated the heat transfer and mechanical property of phase change material (PCM) walls and common wall. Three mixtures of liquid paraffin-46# paraffin, liquid paraffin- lauric acid and capric-myristic acid were prepared and mixed respectively with high-density polyethylene (HDPE) to prepare shape-stabilized phase change materials. Then direct mixing method was used to add these materials into cement mortar in order to make phase change walls. The results shows that the temperatures and heat flow on phase change walls’ surface are all lower than those of common wall; PCMs of different thermal properties have a more and more obvious distinction in heat storage performance with the increasing content of them added in the wall; PCM walls have lower compressive strength than the common one. Results can provide the basis for the application of phase change material walls in real buildings.

Abstract: This paper investigated the thermal performance of shape stabilized phase change paraffin and shape-stabilized phase change fatty acid. And the PCMs are mixtures of 60% 46# paraffin and 40% liquid paraffin, 65 % 48# paraffin and 35% liquid paraffin,30%capric acid and 70% lauric acid, 30%capric acid and 70% myristic acid. Support material is high-density polyethylene. The results in this paper show that: Thermal stability of both of the two types of phase change materials are good, thermal stability of shape stabilized phase change fatty acid is better than that of paraffin. Results in this paper can provide references and basis for the application of phase change material walls in the practice building.

Abstract: Corrosion attacks steel buildings mainly when the connections wait for welding on site. To investigate the effects, a series of experimental and analytical studies have been carried out. This paper summarizes the main results of the experimental studies. The steel welds with and without rust on the welding surfaces were tested and compared in details. The strength of the weld was found to decrease 5% on average. That’s because the rust raised the level of weld porosity. The results obtained above will be considered together with the effect of workmanship in the companion paper, as to assess the seismic reliability for existing buildings with steel moment frames.

Abstract: Based on the analysis of the early shrinkage mechanism of concrete, shrinkage experiment of new concrete restrained by old concrete were conducted to analyze the impact of the different interface roughness on shrinkage stress of new concrete and bonding surface. It is shown that the inner tensile stress of new concrete decreases with increasing of interface roughness, and increase restrained thickness of the new concrete, but it is not significant effect of interface roughness on the shrinkage at bonding surface; the shrinkage strain of section reduces with reduction of the distance of section to bonding surface and reaches minimum on bonding surface, which reflecte significant nonuniformity and increases gradually with age.

Abstract: As a new constructional material, composite sandwich panels are applied in engineering more often than ever. This paper focuses on the structure and foreign research status of sandwich panels which are used in practical engineering problems that need attention. The structure of the composition of the sandwich panel, force characteristics and analysis methods, a set of load-bearing thermal insulation, sound insulation and decoration in one of the new sandwich insulation composite wall form, can comprehensively address architectural, structural safety, and contradict the thermal insulation performance and durability problem. Thus they can be better applied to the engineering practice and meet the development requirement of building energy-saving and adaptation of housing industrialization.

Abstract: The load transfer mechanism of a special-shaped tubular pile with rib is studied by numerical simulation. The results show that a higher side friction can be observed for the radial surface of the rib and the circumferential surface than the side surface of the rib at the same displacement. The influence of rib length and width on vertical bearing capacity are also discussed. It can be found that the length of the rib has a more significant effect on the vertical bearing capacity than the width. The bearing characteristic of the tubular pile with rib is also compared with the ordinary circular section tubular pile to provide a guideline to the engineering application.

Abstract: The issues of energy and environment were two outstanding problems to control our economical and social sustainable development. Our government focused on the development of renewable energy industry all the time, having taken some positive matching policies in order to promote development and utilization of the renewable energy, which has gained great achievements. But with the consumption increase of oil, gas and coal etc, pressures in the ecological environment protection were becoming larger, and energy saving and emission reduction, green development, development of new energy have become the world's economic development strategies. As for China, there are still many difficulties and problems realizing the sustainable development of renewable energy industry, and we need to take the positive study and learn from foreign advanced experience. In biological energy, water power, wind power and solar energy and some like, we need to establish and perfect the relevant measures, and further make the development of renewable energy industry clear in the position of the national strategies. And improving the more positive policy to encourage to support renewable energy industry development, and earnestly carrying out tax, credit, investment, pricing and subsidies policies, supporting renewable energy industry international standards, promoting new energy resources, saving and replacing the fossil energy are the strategic choices to guarantee energy security, optimize the energy structure, and promote national economic and social sustainable development, and protect the ecological environment responding to climate change, to adjust the industrial structure.

Abstract: Based on some economic assumptions, derived the energy equipment and forecast model. Application of this model into China’s energy forecast shows that China’s optimal energy net import amount of 2008 should be 23872 to 30487 and that of 2009 should be 26957 to 33572 ten thousand tons of standard coal respectively, taking China’s energy security into consideration.

Abstract: Based on the environmental Kuznets curve theory, using of panel data of 27 provinces in China during 1990 -2008 and the panel unit root and cointegration methods, the time window for per capita energy consumption inflection point is empirically researched. The results are as follows: China and its eastern and central regions have the environmental Kuznets curve for per capita energy consumption, but it does not exist in the western region. On this basis, the paper studies the scenario analysis for achieving the inflection point of per capita energy consumption for provinces in the eastern and central regions and depicts their specific time path, and finds that China and its provinces in eastern and central regions can have the win-win and decoupling development between economic growth and energy consumption by reducing the energy intensity.

Abstract: This paper uses unit root tests including LLC, IPS, PP and ADF and Pedroni cointegration test to study the relationship between economic growth and energy consumption. By initially determined the casual relationship, we construct an inverted-U curve model to reexamine the connection of the two variables. Evidence from China’s panel data including 29 provinces from 1995 to 2010 supports the inverted-U curve in the relationship and the turning point is at 23432 yuan. The explanation for this is that industrial upgrading and technological innovation are conducive to energy conservation.