ASTM D5249-10 (R2021) PDF Download

ASTM D5249-10 (R2021) standard is a specification that outlines the requirements for backer material used with cold- and hot-applied joint sealants in Portland cement concrete and asphalt joints. The backer material can be in the form of rods or strips and serves multiple purposes.

The standard defines three types of sealant backer material: Type I, Type II, and Type III. These materials have different properties and functions, including limiting the amount and depth of sealant applied to a joint, acting as a barrier interface to prevent backside adhesion (bondbreaker), and providing a form to assist the sealant in developing a shape factor.

The backer material should be easily compressed and installed in the joint reservoir. It should also withstand heat when used with hot-applied sealants. The standard specifies various physical properties that the material must conform to, such as density, tensile strength, water absorption, compression deflection force, compression recovery, heat resistance, and maximum shrinkage.

The standard provides detailed information on the test specimen, test procedure, apparatus, and calculations for evaluating the physical properties of the backer material.