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This paper focuses on successful application of permeable pavement design and performance with special emphasis on stormwater management, water quality benefits, and identification of knowledge and data gaps. The paper provides a summary of the current practice and design methods, discusses the potential application of permeable pavement for highway environment, summarizes the research progress documented in the literature related to mixed design, hydrologic performance, maintenance, water quality benefits, identifies knowledge gaps and unresolved issues, and explores the future direction in permeable pavement application. While there are many successful permeable pavement installations in parking lots and commercial areas with low speed and light traffic loads, only a handful of demonstration projects and simulation studies have evaluated the use of permeable pavements for highways and urban roads with higher vehicle speeds and heavier loads. Those studies and simulations have shown promising results.View the NCST Project Webpage

Under current provision of the Clean Water Act (CWA) and the amended National Pollution Discharge Elimination System (NPDES) all communities with populations of 10,000 or more, which includes nearly all jurisdictions in the United States, are required to regulate and control the discharge of urban stormwater into receiving water bodies. The CWA and related regulatory compliances and societal demands for clean water have exerted a tremendous amount of pressure on stormwater runoff dischargers throughout the United States to develop innovative stormwater treatment and management strategies.A more environmentally beneficial and cost-effective approach to capturing, treating, and slowing down water runoff generated by road surfaces is the use of a full depth permeable pavement shoulder design. Under this proposed design, most if not all runoff will be retained within the shoulder and there would not be a need for additional treatment. The use of permeable pavement shoulders in highly urbanized areas is particularly beneficial since finding sufficient land area to implement other solutions (such as infiltration or detention basins) is difficult.This policy brief summarizes findings from the research project on successful application of permeable pavement design and performance with special emphasis on stormwater management, water quality benefits, and identification of knowledge and data gaps. View the NCST Project Webpage

Concrete pavements develop cracks with the accumulation of fatigue damage caused by the combined effect of vehicular and environmental loadings. In Mechanistic-Empirical (ME) design, the ratio of stresses to some measure of strength is used to evaluate incremental damage, which is then related to cracking. Typically, this measure is the Modulus of Rupture (MOR) of a beam made of the same material. The flexural strength is also known to vary with the thickness of the beam. However, the variation of flexural strength due the presence of eigenstresses from temperature or moisture distributions has not received sufficient attention. A non-linear fracture mechanics model demonstrated that the thickness-adjusted flexural strength can also be used for characterising the maximum elastic stress under a linear temperature distribution. However, under a non-linear temperature distribution, the material may sustain a higher or lower maximum elastic stress than the flexural strength. To model this, a practical analytical expression for the apparent flexural strength was derived and showed excellent agreement with numerical simulations as well as with a model based on equivalent elastic deformation energy. The model was used to show that the fatigue capacity under a typical axle load varies with various non-linear temperature distributions. [ABSTRACT FROM AUTHOR]

Moisture excess in granular pavement layers can decrease pavement performance leading to moisture-related distresses. The combination of trapped water and heavy traffic loads may substantially increase pore pressure and lead to shear failure if layer hydraulic conductivity is insufficient. Currently, most pavement analysis models are unable to predict pore pressure development, so the design and evaluation methods ignore this dynamic effect which may significantly underestimate the moisture damaging effect on pavements. This paper proposes the use of Biot's poroelasticity theory for modelling fully saturated unbound materials. The proposed methodology – Poroelastodynamic Finite Integration Technique (PEFIT) – was used to analyze axisymmetric multilayered pavement structures consisting of elastic and poroelastic layers. The model was verified and validated using a well-known commercial finite element solver and field pore pressure data, respectively. A sensitivity analysis was conducted by varying critical pavement design parameters. The PEFIT analysis of a three-layer pavement system with a poroelastic base layer has shown that a decrease in base hydraulic conductivity significantly increases the maximum pore pressure, especially for high-speed loads. Results also indicate substantial pore pressure and water movement in the base layer, which may induce a potential shear failure mechanism for unbound materials. [ABSTRACT FROM AUTHOR]

During concrete pavement construction, comprehensive information on concrete strength development is necessary for knowledgeable scheduling decisions. To improve in situ strength estimation, nondestructive tests can be combined to maximize available information and increase collection efficiency. Ultrasonic testing has a higher accuracy in strength estimation for early age concrete and the external device allows for more data to be easily collected, while maturity testing can use temperature models to predict strength development. A procedure was created that combines these methods and their strength models in the laboratory for improved and increased field strength data. Using the procedure allows more data to be collected with greater accuracy and provides an adjustable, predicted strength development. This improves the efficiency of fast-track construction projects without resorting to costly alternatives by providing more information on strength development of in situ concrete than traditional strength testing or nondestructive methods individually. [ABSTRACT FROM AUTHOR]

This paper presents a new numerical procedure for the determination of the viscoelastic compliance properties of a matrix phase from a simple three-point bending test on a composite beam. The composite is modeled as elastic inclusions randomly dispersed throughout a viscoelastic matrix. It is also assumed that the spatial distribution of the inclusions in the composite is known or can be determined. Zevin's method of iterative functions is proposed for the determination of the matrix properties. Following a detailed explanation of the proposed scheme, a numerical verification is performed using three-dimensional finite-element (FE) analysis simulations. The proposed scheme was applied to the experimentally obtained creep compliance of the asphalt concrete beam. The obtained viscoelastic properties of the asphalt binder matrix phase were used as input into the FE model to simulate the behavior of the composite beam. An excellent comparison between the experimental data and the predicted beam deflections was observed. This shows that the proposed method is robust and it can be implemented to solve identification problems for viscoelastic composite materials. DOI: 10.1061/(ASCE)EM. 1943-7889.0000126 CE Database subject headings: Elasticity; Viscoelasticity; Numerical analysis; Asphalts; Mixtures; Composite materials; Pavements. Author keywords: Elasticity; Viscoelasticity; Numerical analysis; Asphalts; Mixtures; Composite materials; Pavements.

The Minnesota Department of Transportation began construction on the Minnesota Road Research Project (MnROAD) in 1991 and opened the full-scale pavement research facility to live traffic in 1994. Since the time of its construction, MnROAD, the first major test track since the AASHO Road Test of the 1950s and 1960s, has learned a number of lessons on behalf of the greater pavement community. As part of completing the first phase of MnROAD (its first ten years of operation), researchers at the University of Minnesota reviewed the many products of MnROAD's first phase for a project titled 'MnROAD Lessons Learned.' The Lessons Learned Project involved over fifty interviews, three hundred published and unpublished reports, papers, and briefs, and an online survey of pavement professionals. This paper, based on the Lessons Learned Project, presents an overview of MnROAD products of interest at the local, state, and national levels. Furthermore, the paper provides extensive references for these products in the hopes of increasing awareness of MnROAD's under-publicized contributions to pavement engineering. DOI: 10.1061/(ASCE)0733-947X(2007) 133:11 (599) CE Database subject headings: Pavement management; Databases; Minnesota.

This study considers a plate consisting of one or more layers, resting on a general clastic foundation, and subjected to a nonlinear through-the-thickness temperature distribution, together with arbitrary wheel loads. The resultant bending stress distribution in the plate is presented as the sum of the bending stresses due to the applied loading and to an equivalent linear temperature gradient, pius the pure thermal stresses due to the nonlinear part of temperature distribution. The resulting algorithm has been implemented into finite-element code ILSL2, capable of accommodating one- or two-layered slabs with a temperature distribution through the individual layers described by a linear function, a quadratic function, or explicitly provided by the user at a number of individual depths. Several examples are used to illustrate application of the method.

An algorithm for elastic reactions that can be used to compute other force or deformation variables was reviewed. This algorithm was then compared to a previous solution by Kharlab in 1963 that computes the response of structures undergoing continuous changes under time-dependent loads. This was based on his principle that if the superposition is satisfied, then (i + 1)th delayed restraint acts on the system like it was the first and only restraint.