Mechanical properties and durability of roller compacted concrete pavements in cold regions

Roller compacted concrete pavement is a cost effective and beneficial pavement system which needs fewer material and less energy than other kinds of pavements. An important problem with the pavements is salt scaling that occurs due to a saline solution on cementitious surfaces. In order to reduce the negative effects of salt scaling, the influence of cement replacement by trass, a natural pozzolan, has been investigated. Mechanical and durability tests and salt scaling with air void analysis on hardened concrete were carried out to evaluate the effect of ordinary/trass selected mixes with/without air entraining agents. Results generally showed that although usage of air entraining agents reduced compressive and tensile strengths and increased water permeability and capillary absorption, it performed well against salt scaling in freeze-thaw cycles. The control samples with less w/c performed better than trass samples. In this research, spacing factor obtained about 0.07 mm and 0.1 mm for air-entrained and non air-entrained samples respectively.