Applied Mechanics and Materials Vols. 505-506

Abstract: The indoor molding methods don't match the actual degree of compaction, which will cause the compaction over one hundred degrees and the more reflective cracks of the cement stabilized macadam base. In order to prevent this kind of phenomenon, a series tests on two kinds different molding methods were conducted. It contained maximum dry density, UCS,drying shrinkage performance and impact of aggregates performance .The results show that the dry density and UCS(unconfined compressive strength) of vibration molding are greater than isostatic pressing method's, the drying shrinkage performance of vibration molding is better than static pressure molding's. The vibration molding has less affected for the aggregate performance. It is more similar to the actual field.

Abstract: The author has done the shear experiment of asphalt mixtures at different asphalt aggregate ratio and different confining pressure using the direct shear test machine, then determined the optimum asphalt aggregate ratio according to the maximum shear stress. The asphalt mixture under optimum asphalt aggregate ratio has better shear performance by this method, and this method can better simulate the road surface actual stressful condition, the asphalt mixture has a good ability of anti-permanent deformation and fatigue.

Abstract: Frost-heave and thaw-settlement of roadbed soil in highway will influence directly the durability, safe traffic flow and construction & maintenance costs in high-cold areas, therefore, recognizing and analysing the common embankment technologies of highway roadbed in high-cold areas accurately is significant to the effective controlling of project invest and the highway construction with limited funds in minority areas. The relations of Moisture Content and the freeze-thaw performances of roadbed fillers, subgrade soil were got respectively by experiments, and the results shows: Moisture Content has larger influence on the frost-heave and thaw-settlement performance of the soil. During the embankment of roadbed, the Moisture Content of fillers should be controlled nearby the optimum Moisture Content. The frost-heave and thaw-settlement occurs mainly in the subgrade soil, controlling the Moisture Content of subgrade soil is very important to improve the up-limit of frozen-soil, keep the stability of frozen-soil, control the thaw-settlement of roadbed and get rid of the roadbed diseases.

Abstract: The issues induced by underground mining are worldwide difficulties because the mined-out area is undesirable due to its implicity, complexity and large deformation. This paper describes the harmfulness of golf in highway construction based on the general failure characteristics of overlying rock masses. Grouting method was employed to improve the Banbidian goaf. Verification of the reinforcement effect was carried out using packer test and core extraction. The results show that this technique has achieved desired effects and hence could be referenced by other fellows.

Abstract: The basic technical performance indexes are analyzed between polymer fibers GoodRoad ® II polyester fiber and GoodRoad ® II Acrylic fiber polypropylene by the comparative test. On this basis, influence law of Marshall Index and high & low temperature performances of the AC-16 asphalt mixtures which are influenced by different fiber dose and fiber type are researched. The results can provide the guidance and application value to improve the performance of asphalt pavement.

Abstract: The stability analysis and evaluation on high slope is of great significance. The stability analysis on the slope of ZHANG-ZHUO highway is carried on in this paper by using the strength reduction method and ABAQUS software. According to the stress and plastic deformation calculated by ABAQUS software, the paper gives evaluations for the stability of slope. It turns out that safety factor of the slope is greater than three; the stability of the slope is well.

Abstract: Asphalt concrete is a typical complex of viscous, elastic and plastic.So the raw materials should be fully considered, such as asphalt, aggregate, filler, etc, when research to viscoelastic. Viscoelastic can influence various properties, even to service life of the road and its performance. Therefore, if can improve the viscoelastic properties, it will have a lot of influence to asphalt concrete. Through to add 0.2% sisal fibre to common concrete to study the viscoelastic properties, this article seek to improve the viscoelastic method, in order to play the role of asphalt concrete better.

Abstract: The graded crushed rock layers is set between asphalt surface course and semi-rigidity base course to effectively prevent or reduce the reflection crack of semi-rigidity base course and improve the draining condition of asphalt pavement, however, the graded crushed rock is low in modulus and is provided with nonlinearity stress-strain characteristic, and the addition of this transition layer may cause the stress variation of pavement structure. Through applying KENPAVE pavement design program, analyze the mechanical response discipline on pavement structure layer by thickness variation of graded crushed rock layer and put forward the reasonable suggestions for structural design of asphalt pavement for transition layer of graded crushed rock.

Abstract: Aiming at the asphalt mixture type used in intermediate and underlying course of high-grade highways in Northeast region of China, the research of effect of asphalt and gradation on the low-temperature performance of asphalt mixture was carried out to recommend asphalt grade and grading type which is suitable for intermediate and underlying course of high-grade highway in Northeast region of China. The results show that the asphalt and gradation of aggregate has important impact on the low-temperature performance of asphalt mixture. The low-temperature bending creep rate of Grade A No.90 asphalt mixture specimen prepared is faster than that of Grade A No.70 asphalt mixture. To further illustrate the low-temperature deformation resistance performance of Grade A No.90 asphalt is better than that of Grade A No.70.asphalt.The low-temperature bending creep rate of modified asphalt mixture of gradation GLAC-20 is greatly improved. Grade A No.90 asphalt modified is suggested to use in intermediate course, and the gradation type which is suitable for intermediate and underlying course is recommended for reference.

Abstract: In this paper, two base asphalt types representing two oil sources and two modifiers (linear and star-shaped) are processed. This paper discusses the relation between dosage of SBS and the characteristics of SBS modified asphalt. Modified effects related to the structure and molecular weight of SBS. The modification effect of star-shaped modifier is better but the processing performance of linear modifier is better. The index of evaluating the production quality of SBS modified asphalt is proposed and the basis of controlling the construction quality of SBS modified asphalt is provided. Through the analyses of modified asphalt with different variety and different SBS dosage in conventional experiments such as penetration, ductility, softening point and the relation between the dosage of SBS and various technical performances of SBS modified asphalt is obtained. After the modified, penetration is decreased and softening point and ductility is increased, which prolonged the service life of pavement.