Sulfate Attack on Stabilized and Recycled Materials in Pavements

Abstract

There have been several instances of sulfate attack on portland-cement- and lime-stabilized materials and on recycled portland-cement concrete used in pavements at US Air Force (USAF) airfields. While the chemical reactions are similar to those found in
conventional sulfate attack on portland-cement concrete, the nature of the attack in a pavement setting makes conventional methods for protecting portland-cement concrete from sulfate attack ineffective for these stabilized and recycled materials. This paper will review the nature of the failures encountered on these USAF facilities. These examples show that even use of Type V sulfate-resistant cements proved inadequate to prevent attack. The paper will conclude with a discussion of our current shortfalls in knowledge and guidance in this area.