Conventional chip seal applications have been utilized successfully for over 100 years as cost effective maintenance and rehabilitation strategies. The use of asphalt-rubber binder in a chip seal procedure began in the mid 1960’s and has been known as either Stress Absorbing Membrane (SAM) or Stress Absorbing Membrane Interlayer (SAMI). This was the first use of asphalt-rubber binder and throughout the history of the asphalt-rubber industry this particular application has evolved and improved to a point of consistent, predictable and high quality usage.
This paper will focus on the use of asphalt-rubber materials as the binder for SAM and SAMI applications. Proper binder design, chip seal design and construction procedures will be discussed and applied to the benefits concerning spray applied asphalt-rubber systems for corrective maintenance. Also additional spray applied maintenance systems that have evolved due to specific roadway or project conditions will be discussed.