Applied Mechanics and Materials Vols. 587-589

Abstract: In order to reduce the influence of mixing building material quality variability of asphalt mixture. On the basis of Kunming Changshui International Airport West runway mixing by disk data, The proportional difference standard deviation as the index, Study on the quality stability of the mixture of different types of mixing the raw material consumption variability, hybrid variant gradation and the mixing process. The analysis results show that Factors of mixing type, control accuracy and operating method of great quality variability of asphalt mixture; Different variability of various mixing raw materials; Mixture gradation variability index in 9.5mm, 4.75mm and 2.36mm sieve is greater, And the maximum at 4.75mm; Mixing plant start and end of the mixture quality variability than mixing intermediate stage. Finally, aiming at the mixing plant proposed a series of measures to reduce the mixture quality variability.

Abstract: In order to analyze mechanism of pneumatic tire rollers compacting against hot asphalt pavement, taking the process of wide base tire of rollers compacting against hot asphalt pavement as research object, the wide base tire is loaded up with inflation pressure and axial force to study the contact characteristics. Two finite element contact models are established by ANSYS, one of which is for the contact of wide base tire against rigid pavement, and the other is for the contact of wide base tire against hot asphalt pavement. The static contact characteristics of wide base tire against hot asphalt pavement are achieved though FEA method, including whole deformation of tire, formation variation of contact patch, and stress distribution of contact area.

Abstract: With increasing concentration on highway land issue as the new round of highway construction, reducing land occupation and earthwork volume of highway engineering is necessary under the historical background of building “resource-saving and environment-friendly” society. It’s been widely known now in the industry that subgrade height of highway in China, especially high-grade highways, is on the high side. Therefore, it’s significantly necessary to discuss and study on appropriate subgrade height. This paper explains advantages and disadvantages of low-filled embankment and expounds current situation of indexes for subgrade performance – moisture, modulus resilience and permanent deformation; it proposes basic thinking of determining subgrade height mainly through meeting subgrade performance and engineering requirements and realization approach of the method.

Abstract: For the design of prestressed concrete sleeper, design methods and standards in different countries are different. America and China design sleeper by the allowable stress method, UIC design by probability limit design method. China has design II-sleeper by the method of reliability, but the theory is not immature so that II-sleeper appeared a lot of cracking problem. In recent years, designing IIIa-sleeper still use the allowable stress method. By contrast of process of designing IIIa-sleeper in China and America, include design load moment, the prestress loss, bearing capacity of structure, test and so on. Get the main difference of designing sleeper in China and America, and the rationality and practicability of different design method.

Abstract: This paper studied the influence of WMA to asphalt technical properties through the three indexes and the viscosity experiment of asphalt. It showed that the asphalt properties were affected in different degree with the addition of the WMA additive, and the base asphalt is more sensible to WMA additive than the SBS modified asphalt to it.

Abstract: This paper studied mechanical properties and microscopic changes of CRTSⅡtype CA mortar under the roles of the conditions of water immersion, acid soaking, wet and dry cycling, etc. The results show that: under the role of water immersion, the relative compressive strength decreases and elastic modulus decreases firstly and then increases with the extension of the time; under the role of acid soaking, the relative compressive strength and elastic modulus both decrease with the extension of the time; under the role of wet and dry cycling of short period, the relative compressive strength and elastic modulus both decrease with the increasing of cycling times, but CA mortar exists serious brittleness phenomenon under the role of wet and dry cycling of long period.

Abstract: Temperature changes have a significant impact on the CRTS-II track structure in Beijing-Shanghai high-speed railway which has longitudinally connected type. In this paper temperature fields of ballastless track superstructure are simulated based on heat transfer theory and subroutine of ABAQUS that solar radiation DFLUX and ambient temperature FILM. The results showed that: the maximum temperature difference on the top of track slab is 20°C in summer and 10°C in winter; the maximum temperature difference in CA mortar layer is 4°C in summer and 2°C in winter; the maximum temperature difference in concrete substrate is 2°C in summer and 1°C in winter.

Abstract: The discrete element method is widely used in the design of asphalt mixture in rencent years. Reviewed the relevant studies on gradation design, simulation and experiment micromechanics and summarized the problem exist in asphalt mixture. Finally we put forward several most promising direction in this field.

Abstract: Compared with the traditional framework dense structure, strong embedded squeeze skeleton dense cement stabilized crushed stone has a stronger embedded squeeze force, the more excellent mechanical properties.This article briefly describes strong embedded squeeze the skeleton dense cement stabilized crushed stone grading design and mechanical properties, and strong embedded squeeze Framework Grading cement stabilized crushed stone in the construction of many materials Segregation. Through the experimental contrast research with traditional construction method, the new method almost eliminate the problems of mixture segregation, which can be used for reference in construction application.

Abstract: The amount and nature of filler in asphaltic concrete mixes significantly affect its design and performance. The use of Palm oil fuel ash (POFA) as filler in asphaltic concrete has been studied with varying degree of success, this study therefore, evaluates the effect of POFA on the indirect tensile strength of asphaltic concrete AC 14. POFA was grained and passed through 75 μm sieve; a number of trial mixes were prepared using the Marshal Mix design procedure with 5% POFA to arrive at asphalt concrete mixtures that fulfill the Marshal criteria. The effects of POFA on stability, flow, stiffness and indirect tensile strength of asphaltic concrete (AC14) mixtures at their respective optimum binder content were evaluated. The results show that Marshall stability, flow, stiffness and indirect tensile strength values generally improved in the POFA modified mix compared with the control. POFA modified sample shows 16% improvement on the indirect tensile strength compared to the control.