Field Implementation of Rubberized Chip Seal

016903442018Final Report (September 2017-December 2018)PDFTech ReportCMR 18-012MoDOT project # TR201804Chip sealsCrumb rubberLaboratory testsSkid resistanceSkid resistance testsTextureAggregate retentionBritish pendulum testCuring timeMacrostructureHighwaysMaintenance and PreservationMaterialsPavementsUnited StatesMissouriMissouri University of Science and Technology. Dept. of Civil, Architectural, and Environmental EngineeringGheni, AhmedPourhassan, AlirezaElGawady, MohamedDarwish, YasserSchonberg, WilliamMissouri University of Science and Technology. Department of Civil, Architectural, and Environmental EngineeringMissouri. Department of Transportation. Construction and Materials DivisionUnited States. Federal Highway AdministrationUS Transportation CollectionChip seals have been widely used as a pavement maintenance surface treatment due to its competitive cost and construction time. Recently, the research team developed a rubberized chip seal where natural aggregate is replaced with crumb rubber obtained from recycled tires. During this study, a total of 108 laboratory specimens and a field chip seal section with different crumb rubber replacement ratios were investigated. Aggregate macrostructure, retention, and skid resistance were measured. The crumb rubber showed a remarkable performance in aggregate retention measured using the Vialit and Pennsylvania tests. The values of the mean texture depth of rubberized chip seal specimens were significantly higher than those of the conventional chip seal. Finally, while a reduction in the British Pendulum Number (BPN) was recorded with an increase in the crumb rubber replacement ratio immediately after construction, after a period of more than a year of service life in the experimental section road, the rubberized chip seal segments recorded a much higher BPN compared to that of the conventional chip seal segment. Furthermore, it is recommended also to increase the curing time for chip seal, regardless of aggregate type, to at least six hours to improve the performance of the chip seal