What is the oxidized asphalt or milled tack rate?

The oxidized asphalt or milled tack rate is a critical parameter in roadway construction and maintenance, particularly for applications such as hot mix asphalt overlays. The value represents the amount of tack coat applied to create a bond between an existing pavement surface and new asphalt material.

A tack coat is vital for ensuring that the layers of asphalt bond together effectively to prevent delamination, which can lead to road failure. A tack rate of 0.06 (+/- 0.01) gallons per square yard signifies an effective amount that provides good adhesion without excessive buildup, which could lead to bleeding or other pavement issues.

This specific rate is identified based on empirical research and practical applications in the field that ensure a balance between sufficient bonding and optimal material use. The allowance for a slight variance of +/- 0.01 gallons provides some flexibility in application while ensuring that the performance characteristics necessary for durability and longevity are achieved.

The rates listed in the other choices could either result in insufficient adhesion, leading to potential failures, or excessive application that could cause other issues, making the specified rate an industry standard for effective pavement management practices.