This specification will set the requirements of the material type and physical properties of the non-woven interlayer used in unbonded concrete overlay applications. The purpose of the interlayer is to ensure that any potential for mechanical adhesion of the two cementitious layers is mitigated. The interlayer is a material alternative to hot mix asphalt which has shown susceptibility to stripping in the presence of water intrusion into the pavement section.
The standard will set physical material requirements to include but not limited to lower and upper limits of the nonwoven fabric interlayer by establishing a weight per area, in-plane water permeability, and thickness under load which will establish an alternative to tradition use of hot mix asphalt as a bond breaker in unbonded concrete overlay applications. The current recommended material specification has been endorsed by the FHWA, AASHTO and the NCHRP. The material is currently in use by the concrete industry when an unbonded concrete overlay has been specified.
Keywordsconcrete bond breaker, geosynthetic interlayer,
The title and scope are in draft form and are under development within this ASTM Committee.Back to Top