Advanced Materials Research Vols. 446-449

Abstract: The paper analyzes the Seismic response of the interaction among frame-shear wall structure、foundation and ground with ANSYS, and the internal force dynamic characteristics of the ground floor column and the displacement of structure based on the comparison of consideration and taking no account of the interaction among superstructure、foundation and ground base in the static load and earthquake load. Some valuable conclusions have been given in this paper and may offer a reference for the engineering design.

Abstract: Reuse of the waste tires in highway engineering is very important for reducing pollution, protecting environment and resources. At present, the rubber chippings from waste tire have been widely used in construction and maintenance of asphalt concrete road surface. But there is little research about cement stabilized macadam base with crumb rubber. This paper used the large-scale finite element analysis software ANSYS to build the pavement structure model, assuming the contact conditon as continuity, analyzed the effect of asphalt pavement by changing the thickness and modulus of cement stabilized macadam base with crumb rubber. The results showed that the value of vertical displacement of crumb rubber modified cement stabilized macadam base is larger than the value of cement stabilized crushed stones base, and increasing the thickness and reducing the modulus of base can decrease tension stress of base bottom.

Abstract: For the old concrete pavement with large proportion damage, it can be reconstructed by paving asphalt surface after cracked and stabilized with punching technique. But there is great difference in adopting the cracked size of pavement slab in every place and there is no relational theory basis. So the authors use 3-D finite element method to analyze the relationships of cracked size of concrete slab and load stress, thermal stress, coupling stress in asphalt overlay and pressure stress on the base surface. The results show that the influence of cracked size on thermal stress and coupling stress is much greater than load stress. With the decrease of cracked size, the thermal stress and coupling stress in asphalt overlay decrease rapidly, the stress centralization at joints and cracks lessens evidently, while the pressure stress on base surface increases. Considering the factors synthetically, it is reasonable for the cracked size from 80cm to 100cm.

Abstract: Reclaimed asphalt pavement (RAP) develops rapidly throughout the world. Hot recycling is one way to make effective use of the waste, but the percentage of RAP in hot recycling is no more than 30%. By way of warm asphalt technology, the percentage of RAP can increase greatly. In this paper, warm recycling is researched. The RAP and the virgin materials including aggregates and asphalt are tested and analyzed. Then, two warm recycling mixtures with different amount of RAP are designed and their properties are investigated. As a comparison, the performances of hot recycling are also tested. At last, the performances of warm recycling and hot recycling are compared and discussed. After the laboratory research, the warm recycling made its debut in Beijing and it exhibit very well, which testifies that warm recycling owns good properties. Warm recycling can make use of pavement waste, and it can decrease the emission and energy consumption. Warm mix is environment-friendly and it is promising in the near future.

Abstract: Thermal stress has been an important parameter used in the analysis of the new pavement design. For the purpose of studying the thermal stress for the asphalt pavement of lean concrete base, first of all, three–dimension finite element model of the asphalt pavement is established. The two main objectives of the paper are investigated. One is analysis for thermal stress of lean concrete base, and the other is analysis for thermal stress of asphalt surface. The results show that thermal stress of lean concrete base increases, decrease and increase with increase of base’s thickness, surface’s thickness and ratio of base’s modulus to foundation’s modulus respectively. So far as the asphalt surface is concerned, maximum shearing stress and maximum tensile stress, which are caused by temperature difference, are evident in asphalt surface which is located in transverse contraction joint of lean concrete base of asphalt pavement.

Abstract: In order to study driver’s mental workload when driving on snow pavement, data of snow pavement’s friction coefficient were observed and blood flow, skin temperature and respiration volume of driver’s were obtained through field experiment. Friction coefficient of snow pavement ranges from 0.04 to 0.31. The correlation between temperature of atmosphere and friction coefficient, snow’s thickness and friction coefficient are weak. And the correlation between moisture of atmosphere and friction coefficient, snow’s degree of compaction and friction coefficient are strong. Multi-linear regression model was established among moisture of atmosphere, snow’s degree of compaction and friction coefficient. The average value of inexperienced driver’s blood flow, skin temperature and respiration volume are 171.423mv, 33.263°C and 2317.263ml when driving on snow pavement, which are far greater than that of experienced driver’s and that of inexperienced driver’s when being immobile and driving on non-snow pavement. The effects of snow pavement on mental workload of inexperienced driver’s are obvious. According to driver’s physiological index, calculation model of diver’s tenseness degree was established and it can evaluate tenseness of drivers quantitatively.

Abstract: The subway in a city of China is located in an alluvial plain. There are many universities and residential distribution districts. The vibration influence in corresponding zone of the subway should be made evaluation before construction. Based on the parameters of dynamic soil test, the one-dimensional elastic column is used to simulate for computation of the vertical vibration of the subway site. Considered the nonlinear and pseudo-damping of soil, the ground accelerations calculated are shown in this paper. Finally, according to the results of computation of the vibration response and comparing with the interrelated code authors present the relevant conclusion for environmental assessment for moving vibration of subway in this city.

Abstract: Abstract. To evaluate the low temperature performance of PR PLAST.S modified asphalt mixture, an analog experiment was adopted. It was found that it is not consistent between the evaluated results from TSRST and the content of PR PLAST.S can affect the low temperature performance of asphalt mixture. It also found that there is the optimal content to make asphalt mixture have the best low temperature performance.

Abstract: PAP has widely used in Europe, the U.S, and Japan. As an effective technology for urban stormwater management, PAP not only decreases stormwater volumes but also improves runoff water quality including heavy metals, suspended solids (SS) and nutrients. In addition, it help protects groundwater and urban environment. In this paper the current trends of investigating the purification ability of PAP are introduced. The characteristics, the pavement structures and materials are analyzed. The recent researches in field studies and laboratory experiments are highlighted. The present applications of and challenges to PAP are discussed. Further research needs are recommended.

Abstract: A viaduct of the Qinglai expressway fourth contract was artificial excavated piles. The construction technical work was regarded as an example. The technical comparison were done between the artificial excavated pile and the bored pile on the pile foundation bearing capacity and the retaining wall effect . The artificial excavated pile replacing the bored pile was feasible, and the construction technology and the key problems of the artificial excavated piles were confirmed. The references were provided to the similar projects.