【国外标准】 Standard Practice for Making a Laboratory Pavement Marking Sample Using a Pavement Marking and Drop-on Particles

5.1 The method described in this practice provides a procedure to rapidly generate pavement marking samples in the laboratory, suitable for the testing of applied pavement marking properties.5.2 This practice is intended to provide uniform laboratory pavement marking samples that reduce the variability associated with obtaining pavement marking samples in the field.5.3 This practice is particularly useful for directly comparing applied pavement marking properties as impacted by variations in materials, film thickness, and drop-on particle application rates for quality control or development purposes.5.4 This practice can be used in evaluating pavement marking materials formulated and produced in the laboratory and for drop-on particles specifically made and prepared in the laboratory. It can also be used for testing materials that are already manufactured and either stored as work-in-process or placed in its final packaging. When testing manufactured materials in the finished goods state, it is extremely important that a representative sample of the pavement marking material and the drop-on particles are obtained for use, in order to draw the proper conclusions from any testing done on pavement marking samples made from these materials. For proper sampling of thermoplastic pavement markings in a finished good state, it is recommended to follow Practices D7307 and D7308. For proper sampling of liquid pavement marking with both single and multicomponent materials, it is recommended to follow Practice D8008.1.1 This practice covers a procedure and apparatus for producing a representative laboratory pavement marking sample by applying a pavement marking material onto a suitable substrate, followed immediately with an application of drop-on particles consisting of retroreflective optics or other functional particles such as skid resistance particles suitable for laboratory testing or display. Examples of pavement marking materials appropriate for this practice would include waterborne traffic paint, solvent borne traffic paint, and plural component pavement markings such as epoxy, modified epoxy, polyurea, methyl methacrylate, and thermoplastic pavement markings. Plural component materials with extremely fast gel times might not be appropriate for this practice because the material gels too quickly to allow proper embedment of the drop-on particles.1.2 The finished sample will consist of a pavement marking material applied in a liquid state to a sample substrate at the prescribed film thickness, with drop-on particles applied at the prescribed drop rate and embedment level on the surface of the pavement marking material, and then properly cured. The drop-on particles may consist of retroreflective optics such as glass beads or composite optics, or non-retroreflective particles such as skid resistant particles, or several of these items in combination.1.3 The values stated in inch-pound units are to be regarded as the standard except where noted in the practice. The values given in parentheses are mathematical conversions to SI units that are provided for information only and are not considered standard.1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.1.5 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.