Advanced Materials Research Vol. 859

Abstract: Construction activity in South Korea must entail the process of demolition. There is such a high sense of awareness of the importance of managing ever-increasing quantities of demolition waste. To ensure efficient management of demolition waste, it is critical to quantitatively estimate the amount of demolition waste. Based on such need, this study examined the sub-divided categorization models to predict the amount of demolition waste generation rates (DWGs). For the execution of study, the present researchers collected the data on DWGs from 394 buildings based on the mass balance principles. On the basis of the collected DWGs data, ANOVA analysis was performed to compare mean differences in structure and wall materials. Results of the analysis showed that the amount of DWGs varied, depending on the structure of buildings and the wall materials used. The results also indicated that describing even a single type of DWGs discarded from buildings would require multiple estimation models for demolition waste generation.

Abstract: The rural ecological environment protection, economic sustainable development and eco-village construction need to be explored. Based on the concept of eco-village and eco-village model, the existing eco-village construction models in Shaanxi Province can be classified into four categories: comprehensive development model, modern ecological technology applied model, suburban farmhouse model and folk culture model. The issue during those models development been analyzed. Suggestions of promoting ecological village construction in Shaanxi Province been proposed.

Abstract: Ecological impact assessment is revealed through quantitative the impact of human activities on economic development and on human health to determine a regional ecological or environmental load capacity. Only scientific, reasonable and practical to establish an evaluation system, it may promote the healthy development of the construction industry and emerge more green construction enterprises, so as to contribute more green building community. The paper used analytic hierarchy process (AHP). With this evaluation criterion, we can evaluate green construction level of engineering construction.

Abstract: Recycled concrete is one of the main measures to develop ecological and green concrete, also it is one of the useful ways to obtain sustainable development of buildings, resources,and environment . Conforming to this idea , it is increasingly being valued by engineering and became one of the hot concrete research. In this paper, we start with the concept of green high performance concrete , taking high performance concrete in green cementitious materials, aggregates and admixtures point to cut in ,and describing the characteristics of green high performance concrete and its research situation in details. Besides,on the basis of combining the domestic and foreign development of green concrete,I will point out the problems in the currentre research of recycled concrete .Then Ill give the corresponding countermeasures and propose sustainable research and development proposals by emphatically analyzed the research status and application of recycled concrete at domestic and foreign .

Abstract: With the development of city, city population, regional planning and city ecological environment are facing with more and more tremendous pressure, so the development and utilization of city underground space has become common concern. In recent years, underground structures have been widely applied in the fields of city construction, transportation, defense engineering, water conservancy project etc. Many countries in the world have been the development and utilization of underground space as an important way to intensively implement the land resource and sustainable development of the city. In our country, there is still very great potential of underground space development and utilization of underground structure.

Abstract: This practice mainly uses the analysis research on the dynamic characteristics of bridge structure fluctuation test, determination of natural frequency, damping ratio, mode of vibration of bridge structure, dynamic impact coefficient, response (acceleration, dynamic deflection) test parameters, thus judging the whole bridge structure stiffness, operating performance.

Abstract: Two typical monitoring sections are selected for obtaining the change law of the surface subsidence and the settlement after construction of soft soil foundations, and determining the reasonable unloading time. The research results show that the surface settlement rate is large during the filling stage, the rate decreases after the loading and gradually stabilized. The embankment midline settlement is larger than the settlement of the road shoulder which is concluded from the fact that the subsidence of the middle settlement plate is larger than those of the left and right plate. The surface subsidence rate is less than 5mm per month during the two month before unloading according to the data in the tables. The settlement after construction presumed from the middle plate is more significantly larger than that of left and right sides, hence, as the unloading basis of preloading drainage method in soft soil foundation treatment the settlement after construction which is calculated from the midline monitoring data of the road is appropriate. After 6 months the calculated post-construction settlements of the two sections are in the scope of the design requirement since they decrease with preloading time. The reliable basis is provided for the future design and construction of soft foundation in this area through the research results.

Abstract: The continuous beam bridge is a kind of bridge type used widely on the project. With the design theory and construction technology, prestressed concrete continuous beam bridge shown strong vitality. This design is a high-speed rail (40+56+40) m prestressed concrete continuous beam bridge design, whose width is 12.2m and its maximum Design speed is 300km/h. The form of the railway is double line which is 4.8m far away, and the cross-sectional slope is 2%.ZK load was applied on the bridge. A three-span P.C continuous Beam structure with variable cross-section is used in this bridge. The girder body adopts single cell and single box, the height of beam takes quadratic parabola relation, which is 5m high at the middle fulcrum, while at the side fulcrum and the mid-span is 2.5m. The design uses Midas/Civil to establish the finite element model that is reasonable and simple, analyzing the structure behavior of the girder body under loading, especially the internal forces of bridge structure under dead load, live load and additional force.

Abstract: Modulus of elasticity is an important mechanical parameter in analysis and design of reinforce concrete structures. The present value of modulus of elasticity ，which has rare relation with ratio of reinforcement ，is based on plain concrete. Authors deduced an equation between modulus of elasticity and ratio of reinforcement, and then an experimental study was conducted on 11 groups’ component of reinforce concrete with different ratio of reinforcement. At last, an equation for modulus of elasticity of different ratio of reinforcement determined by regression, using least squared method, was described. A cantilever, whose dynamic characteristics and response were calculated, was taken as an example to analyze influence of ratio of reinforcement on the structural analysis .Result shows that ratio of reinforcement has effect on modulus of elasticity . Moreover, if general modulus is ignored when calculate dynamic response, it will cause deviation.

Abstract: Ultra-High Performance Concrete (UHPC) is a relatively new kind of matierials with excellent mechanical and durability performance compared with the conventional concrete. By making a comparison with the conventional concrete ,the compressive strength of UHPC may reach about 200MPa,which is its significant advantage and potential in applications of bridges. The performance of high tensile strength (especially with some steel fibers) enables the UHPC members to absorb energy and resist impulsive loading. In addition, because of the low porosity, the durability of the material is excellent. Based on collecting and analyzing international research results. the materials and production, and mechanical properties of UHPC were summarized. Together with a general introduction of existing international projects ,the summarization provides a comprehensive reference to further application and development of UHPC products.