The journey to clarifying and simplifying many of Division II and III Road & Bridge asphalt related specifications is nearing completion. As many of you are aware, VAA has been working with VDOT to clarify and simplify many of the specifications associated with asphalt production and placement. These draft specification changes were recently distributed for comments. Through the combined efforts of many members, VAA provided several industry comments to VDOT for consideration. Highlights of the comments include a continued recommendation to move to High Modulus High Binder (HMHB) base mixes as the standard base mix for all VDOT projects. This largely impermeable mix provides for a long term, high performing, perpetual roadway base mix. A recommendation was also made to review the maximum density requirements for our mixes. The existing requirements are based on old Marshall mixes. Today’s mixes are designed for higher in-place density without the potential for flushing or rutting. This higher in-place density provides for a much more durable, long-lasting mixture.
Along with these relatively significant recommendations, we noted the erroneous addition of a prime coat requirement for subbase stone during patching scenarios and a conflicting requirement for bond strength testing in the Asphalt Surface Preparation and Overlay specification. The comment period ended on June 26.