Real-Time Smoothness Measurements on Portland Cement Concrete Pavements During Construction.

摘要

This report presents the findings of a research study conducted to evaluate and demonstrate real-time smoothness measuring technologies for concrete paving. Real-time smoothness refers to measuring and evaluating the concrete pavement surface profile during construction, somewhere along the paving train while the concrete surface is still wet (plastic). These measurements are then used to check for objectionable profile characteristics, things that are known to happen in projects that can affect pavement smoothness. With this information, paving operations can be adjusted on the fly. Ideally, deviations are detected in real time and corrections are made such that the final hardened concrete surface can avoid being ground to achieve the smoothness requirements. The work under this study was executed in three distinct but connected phases. Each phase served to evaluate promising and emerging technologies with the potential to measure real-time smoothness. Draft model specifications and guidelines were developed to facilitate evaluation and implementation of these technologies by state highway agencies. Phase 1 focused on identifying all potential technologies by contacting leading transportation agencies, paving contractors, paving equipment manufacturers, and representatives of concrete pavement associations. Numerous real-time smoothness-measuring technologies were reviewed, and three of these were recommended for further evaluation; however, only two were available to participate in this study. Three additional technologies were identified, but not recommended for subsequent evaluation because they lacked technical maturity or a proven history on concrete paving applications during the time frame for this study. Phase 2 consisted of a thorough field evaluation to evaluate objectively the most viable realtime smoothness measuring technologies identified during Phase 1, the GOMACO Smoothness Indicator (GSI) and Ames Engineering Real Time Profiler (RTP). The research team worked closely with the two technology vendors, an experienced paving contractor, and a host agency. During Phase 2, both real-time profilers demonstrated adequate performance as tools for construction quality control. However, it was clear that these technologies are not suitable for quality assurance devices or for calculation of pay adjustments for smoothness. These findings were corroborated during Phase 3, which consisted of a series of additional field demonstrations throughout the nation. Broad and specific enhancements for these technologies were provided to the vendors at the end of Phase 2, and the most critical issues were addressed during Phase 3. During this phase, the GSI was demonstrated in Arkansas and Michigan, and the Ames Engineering RTP was demonstrated in Texas, Michigan, and New York. This report provides documentation of the field data and performance of these technologies as captured during the three project phases. In general, it was found that the two technologies evaluated in the field have Reasonable agreement to reference profiles; An ability to provide a relative estimate of roughness; and An ability to recognize areas where roughness accumulates the most aggressively (i.e., localized roughness).