Development of a Protocol to Maintain the Winter Mobility of Different Classes of Pervious Concrete Pavement Based on Porosity

Municipalities in the Pacific Northwest are increasingly using pervious concrete pavements (PCP). While this class of pavements offers significant ecological advantages, transportation departments must ensure that the pavements are safe for drivers and pedestrians in the region’s typical adverse winter conditions. To assist transportation departments in implementing more effective winter operations, this study aimed to develop a simple, image-based method to characterize the porosity of PCP.

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Improved Methodology for Benefit Estimation of Preservation Projects

This project evaluated WSDOT’s current process for calculating highway preservation project costs and benefits and then developed an improved approach. To quantify the regional economic benefits associated with its transportation investment projects, WSDOT uses software developed by the Federal Highway Administration known as the Highway Economic Requirements System—State Version (HERS-ST). The researchers developed a tool to supplement the HERS-ST for benefit and cost estimation processes. The improved method, combining the new HERS-ST-BAT tool with HERS-ST, will allow transportation agencies to more accurately and flexibly estimate changes in their own and user costs resulting from proposed pavement projects and to more effectively consider different investment alternatives.

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Preliminary Procedure for the Structural Design of Pervious Concrete Pavements

The growing popularity of pervious concrete (PC) pavement applications has increased the need for establishing its mechanical properties and understanding their relationships with measurable properties for the purposes of designing layer thickness. In this project researchers developed multi-variable linear regression models to predict strength properties for pavement thickness design and developed a recommended thickness design database for low-traffic-volume PC pavements.

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Portland Cement Concrete Material Characterization for Pavement ME Design Implementation in Idaho

This project began development of a database of portland cement concrete material inputs specific to Idaho in preparation for Idaho’s implementation of the AASHTOWare Pavement ME Design software for designing rigid pavements. The Idaho Transportation Department (ITD is transitioning from pavement design procedures based on the AASHTO 1993 Design Guide to AASHTOWare Pavement ME Design (Pavement ME). Pavement ME requires the definition of more than 100 design input parameters. On the basis of this project’s laboratory test results, the report recommends proper values for all PCC Pavement ME material inputs.

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Preliminary Study to Develop Standard Acceptance Tests for Pervious Concrete

The growing popularity of pervious concrete pavement applications, desired for their role in stormwater management and runoff control, has increased the need for development of quality control and quality-evaluation test procedures that are suited specifically for pervious concrete rather than for traditional concrete. This brief study took preliminary steps toward developing appropriate quality control and quality-evaluation test procedures by identifying suitable specimen sizes for testing, proper methods of casting and compacting specimens at the job site, the compatibility of fresh and hardened physical properties, and proper curing methods for compressive strength testing.

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Recommendations for Extending Asphalt Pavement Surface Life within Washington State

This study identified and evaluated hot mix asphalt (HMA) mix design and construction techniques that have potential for improving pavement surface life in Washington state. HMA pavement performance in Washington state varies across the state’s three broad climatic zones. In Western Washington, the average surface life of WSDOT pavements is 16.7 years. In Eastern Washington, the average surface life of WSDOT pavements is 10.9 years, and in the mountain passes, it is as low as 5 years. In addition, WSDOT pavements generally tend to fail first by cracking. However, rutting plays a more substantial role as traffic levels increase. The researchers evaluated and prioritized the application of 17 construction techniques to improve pavement life for Washington’s different climate zones and traffic conditions.

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