This section is composed of three basic subareas: combined sewer overflows (CSOs), sanitary sewer overflows (SSOs), and stormwater discharges. Much of the literature cited came from documents covering noteworthy global conferences (Bathala, 1996; Engineering Foundation, 1996; Hallam et al., 1996; Maxwell et al., 1996; Sieker and Verworn [Eds.], 1996; Society of Environmental Toxicology and Chemistry, 1996; U.S. EPA 1996a; Water Environment Federation, 1996a,b,c). In addition, the U.S. Environmental Protection Agency (U.S. EPA) published guidance documents (U.S. EPA, 1996,c,d,e), which are discussed in more detail in the subsection Regulatory Policies and Financial Aspects.

https://www.jstor.org/stable/pdfplus/29763265.pdf

Urban wet-weather flows

Fiber-reinforced asphalt-concrete – A review

Pavement maintenance is one of the major issues of public agencies. Insufficient investment or inefficient maintenance strategies lead to high economic expenses in the long term. Under budgetary restrictions, the optimal allocation of resources becomes a crucial aspect. Two traditional approaches (sequential and holistic) and four classes of optimization methods (selection based on ranking, mathematical optimization, near optimization, and other methods) have been applied to solve this problem. They vary in the number of alternatives considered and how the selection process is performed. Therefore, a previous understanding of the problem is mandatory to identify the most suitable approach and method for a particular network. This study aims to assist highway agencies, researchers, and practitioners on when and how to apply available methods based on a comparative analysis of the current state of the practice. Holistic approach tackles the problem considering the overall network condition, while the sequential approach is easier to implement and understand, but may lead to solutions far from optimal. Scenarios defining the suitability of these approaches are defined. Finally, an iterative approach gathering the advantages of traditional approaches is proposed and applied in a case study. The proposed approach considers the overall network condition in a simpler and more intuitive manner than the holistic approach.

/pdf/an-iterative-approach-for-the-optimization-of-pavement-3n8m90r9v8.pdf

An iterative approach for the optimization of pavement maintenance management at the network level.

Morphology, rheology, and physical properties of polymer-modified asphalt binders

Freeze-thaw cycling affects the geotechnical properties of soils and must be taken into account when selecting soil parameters for stability and deformation analysis of slopes, embankments and cuts in cold regions, especially those underlain by permafrost. This review examines methods of investigation, testing techniques and the impact of freeze-thaw processes on the physical and mechanical properties of soils. Copyright © 2006 John Wiley & Sons, Ltd.

A review of the influence of freeze-thaw cycles on soil geotechnical properties

This study addresses the relationship between fine aggregate shape properties and the performance of hot-mix asphalt. Aggregate shape was expressed as three independent properties: form, angularity, and texture. Image analysis procedures and indices were developed to capture these properties. The indices were measured for 22 aggregate samples. The samples were related to the hot-mix asphalt rutting resistance measured under wet and dry conditions in the Purdue wheel-tracking device. Among the different aggregate shape properties, texture had the strongest correlation with rutting resistance. Resistance to rutting increased exponentially with an increase in aggregate texture.

Correlation of fine aggregate imaging shape indices with asphalt mixture performance

Predominantly flexible pavement structural response to loads is predicted by using an elastic multilayer analysis. This type of analysis is based on the assumption that pavements are subjected to static loads and that paving and subgrade materials are linear elastic materials. In this paper, ABAQUS, a three-dimensional, dynamic finite element program (3D-DFEM), was used to analyze flexible pavements subjected to moving loads at various speeds. A number of material models were used to represent actual material characteristics such as viscoelasticity and elastoplasticity. The validity and then the application of 3D-DFEM to flexible pavement analysis were examined. Validation was accomplished by analysis of both static and dynamic cases. The static and dynamic verification studies indicated that 3D-DFEM can be used with confidence to predict actual pavement response from moving loads.

Use of a three-dimensional, dynamic finite element program for analysis of flexible pavement

Resilient modulus tests were performed on five cohesive soils sampled from the subgrades of in-service pavements. The stress at 1% strain in the unconfined compression test (Su1.0%) was found to be...

Resilient modulus of cohesive soils and the effect of freeze-thaw

This report presents the findings of a research project to investigate whether the relative contributions of the structural layers to rutting in a hot mix asphalt (HMA) pavement can be determined from an analysis of its transverse surface profile. The report presents a recommended method for estimating the relative contributions of pavement layers to total rutting. The report will be of particular interest to engineers in the public and private sectors with responsibility for the design, construction, maintenance, and rehabilitation of HMA pavements.

Contributions of pavement structural layers to rutting of hot mix asphalt pavements

Multilayer solutions that calculate stresses, strains, and displacements in pavement structures caused by surface loading have been in existence for several years. However, most elastic layer computer software applications have been developed for mainframe computers. Recently, computational capabilities of the practicing engineer have been greatly enhanced by recent developments in personal computers. Results of this study involved development of an accurate and efficient solution to the multilayer problem. In addition, software was developed for use on a personal computer that included routines for backcalculating pavement layer moduli from measured surface deflections. A convergence technique, employing a combination of closed form and numerical solutions, has been developed to provide accuracy of results at the surface of the pavement and near the load. Special methods of solving the system of boundary equations were developed to obtain the terms needed for the closed form part of the solution. Maximum efficiency has been obtained through an in-depth analysis of the parameters affecting accuracy and their relationship with the numerical integration step. In its current form, the computer solution WESLEA is a fully competent three-dimensional solution that will handle up to five layers with varying interface conditions and a maximum of 20 loads. The fifth layer is semi-infinite and can be made stiff based on the choice of modulus of elasticity. A personal computer-based backcalculation program, WESDEF, has been developed utilizing the multilayer program. An evaluation of the new program is made through comparison of identical deflection data using the BISAR n-layered computer program.

Thomas D. White

Papers

Correlation of fine aggregate imaging shape indices with asphalt mixture performance

Use of a three-dimensional, dynamic finite element program for analysis of flexible pavement

Resilient modulus of cohesive soils and the effect of freeze-thaw

Contributions of pavement structural layers to rutting of hot mix asphalt pavements

Multilayer elastic program for backcalculating layer moduli in pavement evaluation