Applied Mechanics and Materials Vols. 71-78

Abstract: According to random field theory, combined with the construction of the characteristics of reinforced concrete structures, based on the geometric significance of the reliability index, the optimization algorithm of the reliability was established, and the reliability calculation algorithm of reinforced concrete structural during construction is proposed based on stochastic finite element method. Based on a stochastic analysis of the practical engineering, the time-varying laws of the reinforced concrete structural reliability index during construction are concluded.

Abstract: How to ensure the whole stability of structure and avoid progressive collapse of structure caused by destruction of local structures under accidental loading have been paid close attention to extensively by researchers all over the world. According to GSA guidelines, FEM model of 3-D frame structure was established by ANSYS software. Failure of frame structure local column is simulated with the method of "killing" columns of long side, short side, corner side, and interior side, and two columns of long sides, in order to explore the regularity for change of series performance parameters when the frame structure suffering accidental loading. And the alternative load path method was used to analyse the collapse of reinforced concrete frame structure. The result indicates that the frame structure local column damage can make structure basic natural vibration period and maximum interlayer displacement angle larger, and make minimum ratio between shearing force and weight smaller, and if two columns of long side are destroyed, the progressive collapse of frame structure will occur.

Abstract: With the development of building energy-saving in China, energy performance contracting, a new energy management system is introduced. Through the analysis of current situation and trends based on domestic and international energy service industry, and also through the research of benefits sharing model between the Energy Service Company and its customers, the author establishes an energy efficiency sharing model, which contributes to the Energy Service Company to avoid operational risks, ensure its operating income, and finally promote the scientific development of energy industry. The advanced EPC model is of great importance in promoting the work of building energy in our country.

Abstract: There were some problems in the building envelop of Huangmuchang village of Zhangjiawan town of Tongzhou zone Beijing city, as a demonstration village of energy saving retrofit in construction of new countryside. The problems include big heat-transfer coefficient, great cold air infiltration capacity, heat drawback, cold bridge and heat bridge etc. In this paper, how to decrease unit area heat load and improve thermal comfort by building envelop retrofit was introduced. The obvious improvements were obtained by comparing the interior temperature of the retrofitted building with that of un-retrofit building.

Abstract: Mechanical properties of recycled concrete under different conditions were studied in this paper. Based on three kinds of replacement percentage of recycled aggregate and four kinds of seawater corrosion conditions, the experimental study of mechanical properties of recycled concrete specimens corroded by seawater and produced under vacuum conditions were conducted, and compared with that of ordinary concrete specimens. Testing results show that compressive strength of recycled concrete decreases with the increase of both the replacement rate of recycled aggregate and the corrosion time by seawater, with the maximum reduce value is 17.96% and 24.52%; Vacuum conditions effectively improve the strength of recycled concrete, improved value is 1.03-1.19 times of the same replacement ratio of recycled aggregate, and 1.00-1.16 times of the ordinary concrete. It provides the reference for marine engineering application of recycled concrete.

Abstract: Aerosol particles in urban areas are deposited in street canyons due to the wind field generated by building blocks. The purpose of this study was to discuss with CFD software the effect on lowering the aerosol concentration in urban space by means of active and auxiliary adjustable wind deflectors installed on the building facade to divert and control the micro-climate wind environment surrounding the buildings. The results suggested that, the wind deflector could produce an enormous improving efficiency for channelizing the particles.

Abstract: Continuous (or generalized) octahedral element bodies can be obtained by intercepting a cube with three groups of failure (or yield) planes successively under true triaxial stress state, on which the stresses are twin stresses. Among the resulting polyhedral characteristic element bodies, isoclinal octahedron and orthogonal octahedron are of particular importance. Strength models of continuous octahedrons are then derived by stress analysis to arbitrary inclined sections in three dimensional stress space, and strain models by the principle of strain analysis, so the plane constitutive relations of concrete can be understood by plane problems transformed by stress-strain space according to the symmetry of an orthogonal octahedral octahedron where an arbitrary oblique plane is parallel to one of three rectangular coordinate axes.

Abstract: It is difficult to reach the request that 65% standard of building energy in china and the goal of China’s science and technology development in 2020 using traditional outer insulation technology. The several combinations of ordinary concrete (1) and bearing ceramsite concrete (2), styrofoam board of external thermal insulation for external wall (3) and cement-based glazed hollow bead insulation system (4) are made thermal calculations and cost analysis separately in this paper based on a practical project of Jiaozuo city. The results indicate that the combination of (2)+(4) is the best one, which reduces the energy saving rate, labor intensity, transportation weight, project cost by 74%, 20%, 30%-40% and 10% respectively.

Abstract: According to the implementation of about 65% of the building energy efficiency standards in china, the existing external wall insulation technology will face severe challenges. The traditional organic insulation materials representative with polystyrene, due to some defects，such as poor fire resistance, poor durability, short service and no synchronous with the life of structure, and environmental pollution, especially to the fires of the CCTV building in 2009 and the building under construction at Shanghai pudong south road NO.1 in 2010, October 8 in morning, have solicited the research and application of the high performance inorganic insulation materials. And the new generation inorganic insulation materials, represented by vitrified microsphere, are getting increasing attention.

Abstract: Green building is the integration and combination of multiple construction techniques based on the idea of green building. The practice of green building should take root in the combination of multiple subjects. Based on the direction of undergraduate teaching of “Integration of Solar Energy and Building”, which is firstly piloted by Shandong Jianzhu University（SDJZU）. This paper discusses the idea and methodology of infusing theory and technology of green building into architectural design. With the analysis of the designs by undergraduates from SDJZU which won prizes on 2009 Taida Int’l Solar Power Construction Design Contest, it also summarized the vital significance of multi-disciplinary integration to the establishment of the idea and improvement of design methodology in green building design.