Advanced Materials Research Vols. 255-260

Abstract: The volume parameters of asphalt mixtures is sensitive to compaction temperature. Warm-mix Asphalt (WMA) was green paving technology, which can allow paving at lower temperature. In this study, a laboratory investigation of the volumetric properties of WMA with Sosabit was carried out by the method of Marshall. And the effect of different asphalt such as modified asphalt such as Kalamay, Shell, SK and Kalamay 90# asphalt on volumetric properties of WMA at different temperature was analyzed. Based on this, the minimum compaction temperatures of WMA with Sosabit was proposed. The result showed that bulk density and VFA are decreasing and air voids and VMA increasing with the decreasing temperature; the volume indicators to meet the regulatory requirements when the temperature is 170°C~143°C for three WMA-SBS temperature and 150°C~115°C for WMA-90#; compaction temperatures of modified asphalt and asphalt mixture after adding Sosabit can lower up to 133°C and 118°C respectively.

Abstract: With the goal of exploring the impact of pavement structure parameters on load stress of super-thick cement concrete pavement, this paper, based on the Quanxing freeway in Guangxi, analyzes the load stress in the situation of the separated type and combined type contact between the cement concrete slab and the lean concrete base by using three-dimensional finite element model. Computational results show that the variation of different pavement structure parameters have various impacts on the load stress of super-thick cement concrete pavement. The load stress σc1 of super-thick cement concrete pavement slab declines with the increase of slab thickness h1 and base thickness h2 and decreases with the reduction of slab length L and the increases of base modulus E2 and subbase modulus Et. Among them, the variation of slab thickness h1 has the greatest impact on the pavement load stress. Thus, there is a quite obvious effect in reducing the pavement load stress by increasing the slab thickness.

Abstract: Silicon manganese is an essential alloy in the manufacture of steel which impart hardness & strength and performs as an oxidizing agent. Large amount of non bio-degradable slag is produced during the manufacture of alloy which was thought of being used http://images.google.co.in/imgresimgurl=http://www.sharpferro.com/images/hc-si-mn_small.jpg&imgrefurl=http://www.sharpferro.com/product_specification.htm&usg=__5lH3ImPsg0lfeC-iwnG5Jw4JUlU=&h=227&w=368&sz=28&hl=en&start=16&um=1&tbnid=7vllkL2PXo%20in the construction industry as aggregates in flexible and rigid pavements as well as Ballast for rail track construction. Use of SiMn slag requires detailed knowledge of its chemical, mineralogical, pozzolanic, volume expansion and strength properties in addition to reaction kinetics which plays an important role in the final valorization of slag as pozzolanic material. The paper discusses prominent experimental investigations on Silico Mangenese Slag as non-conventional or manufactured aggregate being investigated as Material for Road and Rail Track Construction. The tests were carried out to determine its suitability as an aggregate in various construction fields. Initially the index properties were found out for subsequent use in designing of concrete.

Abstract: At present our country highway asphalt pavement in use is becoming more and more common, but early rutting damage serious impact on the road of normal use. Through the huaihai highway pavement rutting investigations, research and experiment analysis, combining domestic and foreign research achievements of rutting, it is concluded that the rutting formation causes and prevention measures.

Abstract: Compressive behavior of asphalt mixture is studied in creep and strain recovery tests observing large nonlinear viscoelastic strains. The nonlinear viscoelastic material model for asphalt mixture is presented, based on a modified version of Schapery’s constitutive relationship. For the description of the nonlinear viscoelastic response of the material, simple creep and recovery tests for different stress levels were executed. An analytical method and a nonlinear fitting procedure by the least square method are developed to determine nonlinear viscoelastic stress dependent parameters. Constant stress creep testing were also performed to validate the developed material model. The model successfully describes the main features for asphalt mixture and shows good agreement with test data within the considered stress range.

Abstract: In view of good geological condition non-cliff side slope road widening or new road construction, after contrasting and analyzing the characteristics of widening pattern of roads that have been built, lattice slope foundation cantilever structure complex road is proposed. Using slope foundation column which is casted depending on hillside, its top connect with deck of bridge supporting on the cantilever beam ,thus forms the flank roadway structure. This complex road can avoid deep-digging and high filling, lower construction cost.The construction method is simple, slope is also stable. Moreover, in the course of road widening, vehicle traffic will basically not be affected. In this paper, the method of construction technology, working principles, engineering application and economic, technical efficiency and environmental effectiveness have been analyzed, it shows that in road widening under appropriate condition, this method is safe and reliable, can significantly simplify the process, lower cost, and also maximize the protection of natural ecological environment.

Abstract: Jin Zhou Long Qi Bay distributes in different areas of shallow marine sediments, it is necessary to predict and control the settlement of soft soil subgrade. The authors have observed the settlement using the level acquiring horizontal basin maps of vertical settlement and transformed them to ideal horizontal basin maps equivalently and then made a comparision. We have calculated the coefficients of earthwork calculation of settlement reversely. The results have shown that the shapes of the settlement curves of numerical simulation are very similar to those measured, the maximum settlements are very close, which further has shown that stone filled treatment subgrade has received significantly control of settlement and the structure has been significantly strengthened. The reverse calculation of the coefficients has enhanced the applicability of the models which can be adjusted according to the soil of different regions.

Abstract: The method to analysis the strength of planetary trains’ carriers of EPB(earth pressure balance) shield machine is presented in this paper. The structure of the shield machine trains is analyzed and the 3-D solid model of the carrier is built with Pro/E. After the load on the carrier has been dealt with, the strength of carrier is calculated by means of finite element method. The results via ANSYS show that the max stress and strain on the carriers are increasing as the increasing load on it. The max stress is lying on the joint point of the carrier and planetary gear shaft because of the bending deformation of the shaft.

Abstract: In order to investigate the pavement performance of cold recycling sulphur asphalt mixture with emulsified asphalt, freezing and thawing test, rutting test,shear test,bending test, fatigue test and compression test were carried out.Results showed emulsified asphalt cold recycling sulfur asphalt mixture possessed an excellent high temperature stability, as RAP content increased,the splitting and compressive strength,shear strength,compressive modulus of resilience,low temperature crack resistance,fatigue performance all gradually reduced.When sulphur content of asphalt mixture RAP is less than 70%, cold recycling sulfur asphalt mixture can meet the demand of road base; when the sulphur content of asphalt mixture RAP is less than 50%, the mixture can meet the demand of the bottom layer of asphalt pavement.

Abstract: The digital image processing technique was applied to analyze and evaluate the coarse aggregate orientation property in asphalt mixture specimens. Specimens produced by Marshall compaction, vibratory compaction, gyratory compaction, and roller compaction were separately evaluated and compared with the core samples drilled from real asphalt pavement. The quantitative index named maximum likelihood angle (MLA) was developed for statistical analysis on the coarse aggregate orientation. It is found that the coarse aggregate orientation properties of the specimens using different compaction methods have great differences, the specimens produced by laboratory Marshall compaction method has no statistical discipline, the specimen produced by laboratory roller compaction method has the best similarity property with the real asphalt pavement. The results indicate that the MLA is an effective index in evaluating the aggregate orientation, and the roller compaction method should be the first choice in laboratory asphalt mixes specimen preparation.