Assessment of the surface permeation properties of recycled aggregate concrete

The water permeability, air permeability and surface permeability of recycled aggregate concrete (RAC) are compared with those of a control concrete made with natural aggregate. The study shows that the permeation properties of RAC depend on mix-design, conditions of curing and drying of samples. Relationships between permeability and other physical characteristics of concrete such as water absorption capacity and diffusivity are discussed. According to the criteria existing for ordinary concrete made with natural aggregate, RAC could be classified as being of moderate quality rather than poor quality. The testing methodology shows that some of the techniques used to measure the permeability of RAC need to be modified in order with the distinctive characteristics of this material.