Effect of Clay Content on Performance of a Crushed Rock Mix

Sustainability and longevity of road pavements assets are of paramount importance to the economic development of any country. Spray sealed granular pavements are the most common type used in heavy duty Victorian rural arterial networks. Their bases are built of high quality crushed rock mixes, with specific gradings that provide, workability, high density and strength in addition to low permeability, when compacted to specification standards. Clay is commonly added to these mixes to provide cohesion between the coarse and fine particles. A certain type of clay, commercially referred to as `Claypro' has been in use in such bases but there are no published studies about how it affects long term performance. Also, it is unknown how varying its content affects the physical and mechanical properties of crushed rock mixes. This paper serves to report the tests and methodology used to address the above for one crushed rock mix. For the materials used herein, the results have shown that varying Claypro content has a significant effect on the shear and compressive strengths.