Wang Y.,China Academy of Building Research
Applied Mechanics and Materials | Year: 2013
In this paper, the test methods of radiation laboratory and data analysis in detail were introduced. The impact of the capillary system with different parameters changing, such as water temperature or water flow the capillary cooling capacity changes, and the capillary cooling system when the initial radiation response time were specificially studied. Under different parameters while cooling capillary volume changes associated with the indoor temperature can be seen under certain conditions, the capillary cooling capacity and room temperature has a linear relationship. © (2013) Trans Tech Publications, Switzerland.
Zhou G.,North China Electrical Power University |
He J.,North China Electrical Power University |
He J.,China Academy of Building Research
Applied Energy | Year: 2015
Experiments were carried out to investigate the performance of a low-temperature radiant floor heating system with different heat storage materials (sand and phase change material) and heating pipes (polyethylene coils and capillary mat) in the floor structure of a test room. Detailed temperatures in both floor structural layers and the air of the room were measured for four different combinations of these thermal mass and heating pipes during charge and discharge operations. The results showed that the floor structure with capillary mat provides more uniform temperature profile in vertical direction of the test room and needs much shorter time (nearly half) to attain the same room temperature than the cases with polyethylene (PE) coils during the charging process. Also, after the heat source was closed, the floor structures using phase change material (PCM) as thermal mass release heat about 2 times longer than the cases using sand. A CFD simulation is also performed which confirms the measured data during the charging and discharging processes. The results indicate the advantages of using PCM - capillary mat combination for low - temperature floor panel typical of solar - hot - water heating system. © 2014 Elsevier Ltd.
Wang Y.,China Academy of Building Research
Jianzhu Jiegou Xuebao/Journal of Building Structures | Year: 2013
The regulations and related contents regarding the minimum story shear for the seismic design of buildings issued in 'Code for seismic design of buildings' (GB 50011-2010) were briefly described. A comparison between Chinese code and other seismic design codes was carried out. The necessity and applicability of the minimum story shear issued by all these codes were discussed. The calculated base shear of a structure may depend on some parameters, such as the seismic intensity, characteristic period of site, structural periods, modes and damping ratios, etc. The relation among the story shear factor and these parameters were described herein in this paper. The responses to earthquake action and wind load of structures which were of different heights or located in different seismic regions may differ from each other. Some of the key parameters calculated for the seismic design of tall buildings as examples were given to identify that the regulations of the minimum story shear are necessary and implementable for the seismic safety of tall buildings.
Yang J.,University of Birmingham |
Du Q.,Chang'an University |
Bao Y.,China Academy of Building Research
Construction and Building Materials | Year: 2011
In the last two decades, a variety of recycling methods for construction and demolition wastes (CDW) have been developed. For instance, as one of the major components in CDW, concrete rubble has been used to replace natural aggregate after being treated. This is known as recycled concrete aggregate (RCA). The property and use of RCA for structural or non-structural concrete have been extensively studied and numerous findings have been adopted in engineering practice to produce sustainable concrete. Concrete rubble, however, is inevitably mixed with other wastes such as crushed clay bricks (CCB). The level of inclusion varies depending on the original construction materials of demolished buildings. The differing properties of CCB from RCA will affect the mix design as well as the physical and mechanical properties of the resulting new concrete when the inclusion level exceeds a certain limit. Separating CCB from RCA presents an operational difficulty in practice and also has huge cost implications. Therefore, it is important to study the effect of CCB with various inclusion levels on the properties of fresh and hardened concrete. This paper reports on a study conducted to investigate the physical and mechanical properties of recycled concrete with high inclusion levels of RCA and CCB and to explore the potential or the limitation of this type of mixed recycled aggregate in primary concrete structures. © 2010 Elsevier Ltd. All rights reserved.
Ludwig H.-M.,Bauhaus University Weimar |
Zhang W.,China Academy of Building Research
Cement and Concrete Research | Year: 2015
This paper aims to review the progress in cement clinker chemistry since the last International Conference on the Chemistry of Cement in 2011. Although Portland cement clinker is still, by far, the most important compound of modern cements we show that there is a strong development of alternatives. This is mainly due to the emission of carbon dioxide during the calcination of calcium carbonate as raw material whose reduction is the goal of international activity due to anthropologically caused climate change. Furthermore, it is an objective to use both more raw materials that are located close to the concrete plants and alternative fuels. Developments in the field of cement clinker chemistry show a potential for alternatives. Thereby we discuss both old and new ideas. But it has been shown that the substitution of Portland cement clinker has to consider not only reduction in CO2 emission during fabrication: For practical solutions the performance in both in terms of strength development and durability has to be adequate compared to the ordinary Portland cement clinker. © 2015 Elsevier B.V. All rights reserved.
Liang Y.-Z.,China Academy of Building Research
Yantu Lixue/Rock and Soil Mechanics | Year: 2012
In the rigid pile composite foundation that pile is long enough and is not more than 6 times the pile diameter, the internal shear force between pile and soil and under friction of the pile-soil interaction, the soil pressure in the top section of the pile only increased at a certain depth range, it decays rapidly with depth and axial force of top pile increases with depth in soil shear stress and friction. Based on this characteristic of the rigid piles composite foundation, when there is rigid pile composite foundation surrounding excavation and the excavation bottom is higher than rigid pile bottom, soil pressure on the retaining structure which is caused by the additional vertical stress of rigid pile composite foundation can be simplified as an inverted triangle; and the maximum earth pressure effect on intersection of the rigid pile top plane and supporting structure, as the depth increasing, the active earth pressure attenuates to zero. It is shown that the calculation method is consistent with the engineering reality.
Wang J.,China Academy of Building Research
Applied Mechanics and Materials | Year: 2012
Fire load exists in the building, and it is generally not the origin of fire occurred and spread, so attention has not been beloved paid although the fire size is closely related with it. It plays an important role in performance-based fireproof design, but the abroad data is used always, then which is not in accordance to the situation of our country. The article is based on national and international standards, and calculated the fire load theoretical maximum of the building to protect the building fire safety and can be referred by performance-based fireproof designer, so we can control the fire dangerous of the building, and then grasp the critical moment while the fire happened. © (2012) Trans Tech Publications.
Li Z.-W.,China Academy of Building Research
Yantu Lixue/Rock and Soil Mechanics | Year: 2013
In soft ground, the lateral displacement of piled foundation and the additional bending moment of the bridge pile caused by the surcharge load is an extremely negative impact on the safety of the bridge. Through the introduction of specific project, the influences of the unilateral and bilateral surcharge load on the lateral displacement and the internal force of the bridge piled foundation are analyzed in-depth using the finite element analysis; and the calculation results and the measured results are compared. According to above analyses, the change rules of the lateral displacement and the internal force of the bridge piled foundation are further understood. By the impact of unilateral surcharge, the lateral offset and bending moment on the pile is much more significant. The inflection point of the pile is occurred at the interface between the soft soil and hard soil. While the additional bending moment of the pile is significant, it will result in pile cracking. By the impact of bilateral surcharge, the lateral offset of the piled foundation is determined by both sides of the load. Unloading both sides at the same time is less impact on the lateral offset of the piled foundation; but it plays an important role in reducing additional moment of the pile.
China Academy of Building Research | Date: 2014-06-17
A vacuum melting furnace for infrared glass, includes an upper furnace body and a lower furnace body that can be connected with each other or isolated from each other. Vacuum melting of the infrared glass is achieved in the upper furnace body wherein the influence of water in the environment is eliminated. The vacuum negative pressure environments can promote separation of hydroxyl in the structure, which achieves removing of hydroxyl in the glass, and then discharging of the molten infrared glass is conducted at atmospheric pressure in the lower furnace body. By using the vacuum melting furnace for infrared glass, infrared glass with good spectrum transmission performance can be obtained with improved property stability and optical homogeneity, which facilitates the preparation and molding of large sized and special-shaped infrared glass products.
Beijing Hang Bo New Material Technology Co. and China Academy of Building Research | Date: 2014-04-29
Provided is a windshield for a high-speed locomotive and preparation method thereof. The windshield comprises an anti-reflection film layer; a first chemical tempering glass layer coated with the anti-reflection film layer on a first side thereof; at least one second chemical tempering glass layer located on a second side of the first chemical tempering glass layer; the second chemical tempering glass layer being bonded together with the first chemical tempering glass layer via a layer of an adhesive film, and adjacent second chemical tempering glass layers also being bonded together via a layer of the adhesive film; an anti-splash film layer, located on an outer side of the outermost second chemical tempering glass layer and bonded together with the outermost second chemical tempering glass layer via a layer of the adhesive film; and a first electric heating element disposed inside the adhesive film layer in contact with the first chemical tempering glass layer. The windshield of the present invention can meet requirements for the high-speed locomotive, and especially can meet the safety requirements for the high-speed locomotive.