Development of distress condition index of asphalt pavements using LTPP data through structural equation modeling

Traditional pavement distress index such as the Pavement Condition Index (PCI) developed by U.S. Army Corps of Engineers determines coefficients of distresses based on subjective ratings. This study proposed an asphalt pavement distress condition index based on various types of distress data collected from the Long-Term Pavement Performance (LTPP) database through Structural Equation Modeling (SEM). The SEM method treated the overall distress index as a latent variable while various distresses were treated as endogenous and other influence factors such as age, layer thickness, material type, weather, environment and traffic, were exogenous observed variables. The SEM method modeled the contributions of various distresses as well as the influence of other factors on the overall pavement distress condition. Influences of age, layer thickness, material type, environment and traffic on the latent distress condition were in accordance with previous studies. Compared with previous attempts to model latent pavement condition index utilizing SEM method, more pavement condition measurements and influencing factors were included. Specifically, this study adopted the robust maximum likelihood estimator (MLR) to estimate parameters for non-normally distributed data and derived the explicit expression of latent variables with intercepts. A multiple regression prediction model was built to calculate an overall condition index utilizing those measured distress data. The established pavement distress index prediction model provided a rational estimation of weighting coefficients for each distress type. The prediction model showed that alligator cracking, longitudinal cracking in wheel path, non-wheel path longitudinal cracking, transverse cracking, block cracking, edge cracking, patch and bleeding were significant for the latent pavement distress index.     

Incorporating socio-political criteria into the maintenance prioritization of Chilean urban pavement networks

Managing urban pavement networks presents additional challenges when compared to the management of interurban pavements. In particular, the prioritization of maintenance activities – which is critical when resources are limited – requires special considerations. Within these considerations, there are socio-political criteria that are not formally considered in current UPMS (Urban Pavement Management Systems). In practice, decision makers consider these socio-political factors but without a formal procedure and proper information, leading to decisions based on subjective information, which lack traceability and reliability.The objective of this study is the identification and formal definition – including the quantification method – of socio-political criteria relevant for the sustainable management of urban pavement networks. The research method included the application of interviews and a survey of experts and practitioners in various agencies involved in the pavement maintenance decision-making process in Chile. As a result of the study, five primary socio-political criteria were identified: neighbors’ perception, proximity to critical infrastructure, benefited population, presence of alternative routes, and strategic selection based on public policy. These criteria were formalized – including how they should be quantified – through an expert panel. A regression analysis applied to various scenarios considered in the survey resulted in the quantification of the relative importance of the formalized socio-political factors to be considered in the decision process, complementing technical and economic criteria. Future research will explore the use of Geographic Information Systems (GIS) to quantify the recommended socio-political factors and implement them in an UPMS.     

矿渣材料在路面基层中的再利用研究

通过对矿渣、水泥稳定矿渣、水泥稳定矿渣碎石的试验研究,阐述了一种在路面基层中经济高效的利用矿渣材料的方法。     

浅谈改性沥青路面现场热再生技术的应用

改性沥青路面现场热再生技术是一项应用于改性沥青混凝土路面的维修技术,对该项技术施工工艺及施工中应注意的问题进行了介绍。     

热拌沥青混合料面层施工及质量控制

总结了热拌沥青混合料面层施工的设备要求、材料质量要求、施工工艺要求和监理控制重点,并在多条高速公路中运用,取得了一定的效果,在高速公路施工中可以借鉴。     

沥青混凝土路面平整度的施工控制探究

本文结合沈山高速公路路面维修中沥青混凝土路面施工新工艺和新方法,重点落实控制质量,工程实践与实施过程相结合,分析了影响沥青路面施工平整度的具体因素,指出了提高沥青路面平整度的具体措施。     

几种改性沥青零剪切黏度的测试分析

对基质沥青和4种改性沥青分别进行高温条件下的稳态流动试验和静态蠕变试验,应用流变模型拟合零剪切黏度（ZSV）,并对拟合结果进行深入分析。结果表明：稳态流动试验可反映沥青的稳态流动状态,由该试验拟合的ZSV与60℃动力黏度具有较高的相关性,能较好地评价基质沥青和部分改性沥青的高温性能,但无法准确描述高强改性沥青优秀的抗车辙性能;两种试验结果拟合的改性沥青ZSV相差很大,静态蠕变试验的拟合结果明显偏小,说明改性沥青尚未进入稳态流动状态,需要更长的蠕变时间才能获得准确的ZSV。     

纤维混凝土路面的应用与发展

阐述了纤维混凝土路面的应用与发展。     

"RDS-8固化酶"在道路工程中的应用

文章简要地介绍了RDS-8固化酶稳定土的研究,通过室内试验和试验路,证明了RDS-8固化酶稳定土较优良的路用性能及适用范围,在道路工程应用中达到使用安全方便、减少筑路造价、节约能源等效果。     

浅谈沥青路面平整度的处理措施

分析了路面不平整产生的原因,并提出采取相应措施.