Advanced Materials Research Vols. 671-674

Abstract: Stability of the road embankment is the foundation of the highway normal operation and maintenance, so there is strict requirement of road subgrade settlement for the highway. This article uses the gray theory to predict Cheng Chi high embankment construction settlement and builds a predicted model and tests the model’s accuracy. The results of settlement prediction are under the limits, so the stability of the road subgrade is good. This dynamic prediction method can be used on prediction of the settlement of high embankment and it’ll direct the operation and ensure the maintenance safety.

Abstract: To evaluate the high temperature properties and rheological behavior of Iranian Rock Asphalt(IRA), convectional test and temperature scanning test over modified asphalt containing A-70 asphalt as base asphalt and IRA as different amount were conducted. The results show 1) an increase in asphalt binder’s capability of deformation resistance under high temperature, decreases both in asphalt binder’s temperature sensitivity and low-temperature performance; 2)an increase in anti-rutting factor, a decrease on loss tangent value, an improvement of dynamic viscosity. Thus the asphalt binder’s high temperature performance is greatly improved and anti-rutting capability strengthened.

Abstract: At present, distresses of national bituminous pavement are mainly rut and crack. Occurrence of these two distresses seriously affects usability and service life of bituminous pavement. The author studied the severity and causes of pavement’s rut distress and crack distress combining with investigation of a highway. Corresponding treatment measures were also proposed aiming at pavement distress characteristics. Determined fiber patching material had good effect on the improvement of bituminous mixture high temperature stability through indoor test and entity paving of pavement, and gave priority to it as pavement patching material.

Abstract: The aging of asphalt pavement gets serious in the course of service due to the large number of vehicles and high pavement temperature. A survey was conducted on urban road’s asphalt pavement in the city of Tianjin. By analyzing the extracted asphalt sample from asphalt pavement built in different years, it shows that asphalt’s softening point and viscosity increase but its penetration and ductility attenuate with the extension of service period. Of which, the ductility changes dramatically with its ductility attenuating fast in the early years of service and the attenuation of ductility tending to slow down later. The vertical difference of aging in different depth of pavement is marked and degree of aging tends to attenuate from the surface to the center.

Abstract: For the research on the application of basalt fiber reinforced concrete in highway engineering, indoor experiments were carried out to study the preparation technology of basalt fiber reinforced concrete specimen. The best preparation technology has been got from the analysis of the test results. Scanning electron microscopy (SEM), combining existing fiber reinforced concrete reinforcement theories were used to analyze the enhancement mechanism. According to analysis on the pavement performance indexes of basalt fiber reinforced concrete, it is proved that basalt fiber can significantly improve the flexural strength of cement concrete, especially for early strength. Basalt fiber reinforced concrete has an advantage in improving the construction efficiency, rapidly opening traffic and increasing social economic benefits when used for the rapid repair and construction of the pavement.

Abstract: With low content in CaO, blast furnace slag is a unique local engineering material with characteristic of multi-hole structure and high strength. Based on requirement of highway base material, strength performance test and feasibility analysis is conducted in this paper. With different proportion of cement content, through comparison of test data between cement stabilized slag and traditional cement stabilized material, traditional gravel aggregate could be substituted completely by Pangang blast furnace slag in application of highway base.

Abstract: In view of ballasted-CRTSⅡ ballastless track transition section on the bridge of Beijing-Shanghai high-speed railway, the influence of track random irregularity and pier foundation settlement difference on acceleration and stability index of locomotive body are discussed by the finite element method. And then, by using the index of rail deflection gradient to describe the law of dynamic interaction, rail-wheel dynamic response, attenuation distance of locomotive body acceleration and change of sleeper pressure caused by under-rail stiffness difference are analyzed. Finally, the recommended value of reasonable length of transition section is put forwarded.

Abstract: The mechanical response of lightweight concrete multiple shear rivet pavement on the steel box girder bridge deck under wheel loading are analyzed by finite element method. Besides, the effects of various distance、diameter、height of shear rivet to pavement, are researched as well as the effects of thickness of lightweight concrete. Then some recommended parameters are put forward for the paving project.

Abstract: Coupling beams of coupled shear wall system in seismic regions are required to have high load resisting capacity and excellent ductility and energy-dissipation capacity. To achieve this goal, the concept of steel-concrete composite coupling beam is proposed. The steel-concrete composite coupling beam is a new form and worthwhile to research and promote. Further, it is a new direction for the future development of the coupling beam. But there is a lack of specific calculation method and constructional measures in the current related codes. In this paper, the review of available literatures is made including the experimental study and influence factors of mechanical behavior. It works that have not yet been covered after summarizing each research methods and research contents, which will provide scientific reference material for the intensive research on steel-concrete composite coupling beam.

Abstract: A centrally reinforced column is a new type of RC columns, formed by providing a reinforcement skeleton at the central part of the cross section of an ordinary RC column. Tests have shown that as compared with an ordinary RC column, this type of columns has a higher load carrying capacity and ductility. From the pushover analysis of a frame composed of ordinary RC columns and one consisting of centrally reinforced columns, their seismic performance under seismic load of 9-degree intensity was studied according to Chinese code, including target displacements, story-level displacements, interstory drifts, appearance and development of plastic hinges. The results indicate that although the dimensions of cross sections of columns in the frame with centrally reinforced columns are smaller than those of the ordinary frame, the former still has a higher overall load carrying capacity and seismic performance than the latter.