This practice provides procedures for the determination of the retroreflective performance of pavement markings. This practice does not set the minimum retroreflectance values for pavement markings, it describes sampling criteria for determining the retroreflective properties of pavement markings, which then can be used to determine compliance with a specification. It is the responsibility of the agency having jurisdiction to set the acceptable retroreflectivity values within their own specifications.
This practice does not purport to address all the concerns regarding contamination of the markings, but the following may be helpful. It is very important that the markings being evaluated are clean and dry. If the evaluation is being used relative to a measure of the performance of a contractor, it is imperative that the parties agree beforehand on the definition of clean and dry. There are many forms of contamination on a roadway that will lower the retroreflectivity readings of a marking, but not all of them can be removed. Asphalt oil and rubber skid marks are examples. Loose dirt can be removed by pressure washing, perhaps using soap, brushing or high-pressure air, however, these techniques are usually insufficient to remove dirt that is packed into the marking surface. Care should be taken to select areas that are typical of the marking section, avoiding areas of paint tracking or contamination, for example. It may be useful to take photographs using a digital camera and a good macro lens to be able to see the contamination on or between the glass beads.
1.1 This practice describes several field techniques to evaluate the retroreflective properties of pavement markings containing retroreflecting optics (for example, centerlines and edgelines) and applied to the road surface. The techniques described in this practice contain sampling criteria such as the length of test sections and the number of measurements needed. The practice is based on retroreflective measurements made with portable hand-operated instruments in compliance with Test Method E1710.
1.2 The data obtained from this practice can be used to determine the acceptance or rejection of a project based on specified levels of retroreflectivity established by the agency having jurisdiction.
1.3 This practice can be used for the evaluation of newly installed or existing pavement markings. When testing newly applied pavement markings, it is recommended that the evaluation be done no sooner than 48 hours after application but before 30 days after application so that excess retroreflective optics, such as glass spheres, are no longer present.
1.4 The assessment techniques in this practice are based on best practices and designed to provide three levels of confidence in terms of quantifying the retroreflective performance of markings. Each technique represents a tradeoff between the number of measurements and the confidence of the retroreflective performance of the markings under study.
1.5 This practice can be used by agencies as is or may be customized to meet an agency’s specific needs. Where applicable, the practice describes areas where different assumptions could be made, which would impact the sampling needs and the confidence levels of the results. When deviations from this practice are made, they shall be documented in the test report.
Note 18212;When measuring newly installed pavement markings, there are several factors that contribute to erroneous values for measurements made within a short time after application, such a......
Copyright ©2024 All Rights Reserved