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.
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.
Xu H.,China Academy of Building Research
Lighting Research and Technology | Year: 2012
Effective colour rendering can be said to occur when the colour appearances of differently coloured objects are significantly different from each other and occupy a large volume in colour space. A measure called the colour rendering capacity (CRC) is introduced to assess whether a given light source assists effective colour rendering. By calculating the CRC, a range of computer-simulated spectral power distributions are examined and two spectral band positions leading to exceptionally high CRC are identified. The gamut area index (GAI) is also calculated. A very significant correlation between GAI and CRC is observed, suggesting that the GAI could be equally useful in assessing the effectiveness of colour rendering. © The Chartered Institution of Building Services Engineers 2012.
Jin X.,China Academy of Building Research
Jianzhu Jiegou Xuebao/Journal of Building Structures | Year: 2011
The national standard 'Load code for the design of building structures' has been revised against the general background of global climate change, global anti-terrorist and globalization of economy. The main principles and points of the revision of the code can be outlined as: Based on the statistics of recently collected climate data, the reference wind load and snow load for cities all around China shall be updated. The reference air temperature will be provided to cope with the threat to structural safety which may be caused by disasters of extreme weather. Thermal actions and accidental loads shall be added so that the scope of the code will be expanded from direct action only to direct and indirect actions to fulfill the need of design against the actions of thermal, explosion and impact for specific building structures. Overall amendment for wind load covering wind profiles, pressure coefficients and expressions of along wind dynamic response shall be carried out and enhanced so that the expressions and parameters used for determination of wind load will be more reasonable, transparent and international. Provisions for calculation of equivalent wind load induced by cross-wind and torsion dynamic response shall be prescribed to meet the need of design for super high-rise building projects.
Yang J.,University of Birmingham |
Du Q.,Changan 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.