Recent ICT reports online

The following reports from recently completed ICT projects are now available on our website …

R27-161: Construction and Performance Monitoring of Various Asphalt Mixes in Illinois: 2016 Interim Report. Five experimental projects were constructed to better determine the life-cycle cost and performance of pavement overlays using various levels of asphalt binder replacement (ABR) from use of reclaimed asphalt pavement, recycled asphalt shingles, and crushed concrete. The ABR varies from 15% to 48% in the experimental sections. The study of these projects prior to construction, during construction, and for a short monitoring period after construction is intended to determine the impact of various pavement conditions, pavement cross-section, mix design, and material properties on the ultimate performance of the hot-mix asphalt overlay. This second interim report documents the construction and initial testing of three of the five projects constructed in 2015. Also included in the report is an update on the performance of sections constructed in 2014 and the total recycle asphalt sections constructed in 2013. (The first interim report, published in February 2016, is available here.)

R27-169: Opportunistic Traffic Sensing Using Existing Video Sources (Phase II). The purpose of this study was to investigate methods for automatic traffic sensing using traffic surveillance cameras, red light cameras, and other permanent and pre-existing video sources. Success in this direction could potentially yield the ability to produce continuous, daily traffic counts where such video sources exist. The methods investigated come from the field of computer vision, including optical flow, background subtraction, and object detection and tracking, as well as control theory for fusing the results of these methods. The system developed as part of this project outperforms the state of the art in vehicle tracking, and it runs at faster frame rate. More work remains in improving robustness to occlusion and to improve accuracy of nighttime imagery.

Validation of Hot-Poured Crack Sealant Performance-Based Guidelines: Asphalt Crack Sealant Field Installation Guidelines. This report aims to guide pavement maintenance personnel in the selection, installation, and evaluation of materials for hot-poured crack sealant treatments for flexible pavements. The information provided in the guidelines is based on the field performance of 17 conventional sealants installed at five different sites in North America as part of the FHWA TPF-5 (225) pooled fund study: “Validation of Hot-Poured Crack Sealant Performance Based Guidelines”.

Validation of Hot-Poured Crack Sealant Performance-Based Guidelines. This report summarizes a comprehensive research effort made to validate thresholds for performance-based guidelines and grading system for hot-poured asphalt crack sealants. An extensive field performance study, incorporating a wide spectrum of commonly used sealants installed in eight test sites around the United States, was conducted, and the short-term and long-term aging effects of hot-poured crack sealants were evaluated. The research proposes new guidelines for full implementation as AASHTO specifications. In addition to the validated and revised thresholds of existing protocols, the research proposes a modified adhesion test and a simplified test for evaluating tracking resistance. Close inspection of the installation techniques and early performance feedback supported the development of a set of guidelines for crack sealant installation and application.