As the demand for aggregate in construction increases, recycling concrete waste as aggregate has been recognized as an environmentally sustainable solution with potential cost savings. It would allow recycling of construction and demolition waste and reduce some of the need to quarry and haul virgin aggregate. However, the use of recycled concrete aggregate (RCA) has been limited by concerns over its quality and performance, and by lack of uniform specifications as to what kind and how much of the aggregate to use in pavement construction. Studies and on-the-ground experience have shown that high levels of RCA reduce the durability of pavements. The effects of lower replacement levels have not been well documented, however.