Accelerated Laboratory Evaluation of Joint Sealants Under CyclicLoads

摘要

The sealing of joints and cracks in pavement structures has been in practice since thernearly 1900s. The optimized selection of joint sealant products can extend pavementrnservice life and reduce annual maintenance and rehabilitation needs particularly inrnregions which experience extreme climatic conditions.rnEarly sealant materials were not subjected to standardized testing procedures and manyrnfailed as a result. Since then, several test procedures have been investigated and a fewrnhave been accepted into approved standards, such as the American Society for Testingrnand Materials (ASTM), for many of the materials on today’s market. Variability withinrnthe sealants and the empirical nature of the tests have been ineffective in predictingrnsealant behaviour in the field. In addition, ASTM laboratory test procedures require longrnand sophisticated tests that many highway or transportation agencies are unable tornperform, relying on past performance or previous field trials. This potentially leavesrnmany newer and better performing sealants off the approved list of many agenciesrnbecause of the lengthy and expensive process of field acceptance.rnThe purpose of this research was to investigate and rank the performance of eight hotrnpour joint and crack sealant materials for applicability of use in Manitoba through arnperformancebasedrnlab testing approach. The project involves laboratory testing ofrnsealant materials to verify fundamental properties and performance simulation underrncyclic loading. Sealants were tested using a repeated compressive and tensile fatigue testrnat +30oC, 0oC and -30rnoC.rnThe results of the laboratory tests indicated that Type I sealants exhibited higher initialrnload values and also experienced adhesion failure at both the 0°C and -30rn°C testrntemperatures. The Type IV sealants generally exhibited lower resistance to load and threernof the eight sealants did not show signs of failure at any of the three test temperatures.