In recent years, urbanization has developed rapidly, and urban road play a vital role as the premise. Due to the good effectiveness of asphalt pavement, which is more popular in urban road, and road maintenance demands are also increasing. In order to make the maintenance work appropriate, accurate pavement performance evaluation is the premise. This paper collects the data of a road pavement condition in Shanghai and calculates the sub-indexes of each section. We use the entropy weight method to obtain the influence degree of each sub-index. Then we use the revised set pair analysis to construct the comprehensive performance evaluation model of urban road pavement. The analysis shows that compared with the standard method and the set pair analysis, the revised model is more objective, in line with the actual use of the road.
Natural aggregates are gradually experiencing resource shortages and price accumulations with the rapid development rate of the highway construction industry. Therefore, new materials with social and economic benefits must be identified to replace natural aggregates. Limestone was selected as the representative of natural aggregates, and waste glass and waste ceramics were chosen as the representatives of solid waste in this article. This was undertaken to compare their physical and mechanical properties and the adhesion performance between bitumen and aggregates and to investigate the applicability of solid waste in asphalt pavement. The chemical and mineral compositions of these materials were tested by an X-ray fluorescence spectrometer and an X-ray powder diffractometer. The adhesion performance between bitumen and aggregates was analyzed by establishing adhesion and spalling models based on surface energy theory. Results show that the sizes of glass and ceramics must be small, characteristics which are unsuitable for use in high-grade roads. Glass and ceramics are more adhesive to bitumen than limestone and are suitable for areas with a considerable amount of rainfall and insufficient drainage systems. This article can promote the recycling of glass and ceramics and also provide a research idea for verifying the suitability of other solid waste in asphalt pavement.
Aiming at horizontal and vertical uncoordinated deformation formation in Tram Subgrade, a 3D finite element model was established, which was used to analyse the mechanical response of tram monolithic roadbed on multiple depth and width of uncoordinated deformation. The results show that the uncoordinated deformation’s depth has little influence on the mechanical behavior of roadbed, and it indicates that there was remainder disengaging under the monolithic roadbed by the load of tram. On the other side, the width of uncoordinated deformation has a remarkable effect on outstanding to the horizontal tensile stress (σdy) in the slab bottom, deflection (Dd) on the top of slab, compressive stress (σsz) on the top of soil, and deflection (Dss) on the top of soil. The deflection on the top of subgrade surface is about 1.61mm. Therefore, the designer’s attention should be paid to avoid uncoordinated deformation width in the project, and avoid destroy of monolithic slab.
Although trams have been widely recognized, systematic and comprehensive research on their design and construction is lacking. Based on the ABAQUS finite element software, we constructed a three-dimensional finite element analysis model of the overall track bed of the tram. Taking the most unfavorable working condition of load and temperature coupling as the research object, that is from 5:30 to 6:00 a.m., the load was applied to the plate end position. The simulation experiments were carried out by selecting different thicknesses of the track bed slab, support layer thickness, contact conditions between the track bed slab and the support layer, the modulus of the track bed slab, the modulus of the support layer and the soil foundation strength, and the stress and deflection of the subgrade were calculated. The most unfavorable load–temperature coupling condition was taken as the research object, that is, applying a load of 5.5–6 points on the plate end. Different track bed slab thicknesses, support layer thicknesses, contact conditions between track bed slab and support layer, track bed slab moduli, support layer moduli, and foundation strengths were utilized to conduct simulation tests for calculating the stress and deflection of the subgrade. Under the coupling effect of load on the end of the slab and the effect of temperature, changing the thickness of the track bed slab and the coefficient of friction between layers can improve the lateral force and deflection of the track bed slab. The effect of deflection is small. Changing the thickness of the support layer has an insignificant effect on the stress on the top surface of the soil foundation and the deflection of the top surface of the subgrade. The modulus of the track bed slab can affect the lateral force and deflection of the track bed slab, but it only slightly affects the longitudinal force and deflection of the track bed slab and the longitudinal and lateral force and deflection of the soil foundation. The modulus of the supporting layer only slightly affects the vertical and horizontal force and deflection of the track bed slab and soil foundation. The soil foundation modulus has the greatest influence on the vertical and horizontal forces and deflection of the track bed slab and soil foundation.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
334 Leonard St
Brooklyn, NY 11211
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.