Hot-pour sealants come in different grades according the job requirements. Standards for what grades are suitable for what jobs are set by the American Society for Testing and Materials (ASTM). All Koch sealants are ASTM-compliant.
Joints allow pavement to expand in the summer and contract in the winter. Ordinary maintenance of roadways and sidewalks includes resealing pavement joints. In a large field test study conducted for the Strategic Highway Research Program (SHRP) and the Federal Highway Administration (FHWA), Koch 9005 sealant was found to be comparable to silicone-based sealants for use in highway joint resealing.
Other factors taken into consideration when deciding what grade of Koch Sealant should be used are location and purpose. The sealant best suited for use on highways in the hot, dry southwest is not the same sealant as that which will work best on northern highways. By the same token, while an oil-based sealant is suitable for the joints in a small, rural airport runway, the same sealant will break down if subjected to the jet fuel sprays encountered on the runways of large urban airports. In a 10-year study conducted by the U.S. Army Engineer Research and Development Center, Koch 9005 was one of only two sealants that had a 50 percent loss of adhesion after 58 months in a jet fuel environment.
