The Effect of the Dedicated Binder on the Properties of Cold Recycled Mixtures

The most important priority in the field of environmental protection is the implementation of the principle of closed - cycle materials management in construction. This problem also plays an important role in road construction. Due to the increasing traffic load of heavy vehicles and the impact of climatic factors, the road structure is subject to destructive processes that lead to the loss of its durability in time. Therefore, the roads periodically need to be modernized. Very often, it is necessary to carry out critical activities on the foundation to improve the load - bearing capacity of the pavement structure. As part of these works, large amounts of reclaimed asphalt and aggregate are obtained during milling of the lower structural layers of the surface. Applying the principle of closed - cycled material management, the most effective technology for using this material is its re - construction using deep cold recycling technology. This technology uses hydraulic binder and bituminous emulsion, and currently, more and more often, foamed bitumen. Due to the fact that the materials obtained from road structure layers are of very different quality, it is necessary to use a binder that will be dedicated specifically to the materials used (reclaimed asphalt pavement, reclaimed stone). In experiment Portland cement CEM I 32.5, hydrated lime and cement by - pass dust as a by - product obtained from cement plants were used. All components were mixed in various proportions controlled by experiment plan. The influence of a dedicated binder on absorption, dynamic modulus, phase angle in the specific temperature range and rutting resistance of a cold recycled mixture designed with reclaimed asphalt pavement, reclaimed aggregate and foamed asphalt was examined. The obtained test results were subjected to statistical analysis using the ANOVA test in order to determine the significance of the influence of individual components of the dedicated binder on the considered parameter of the cold recycled mixtures. It was determined that the dedicated binder used for the tested recycled asphalt mixture ensures its most favorable parameters when contains: 40% CEM I 35.2, 20% hydrated lime and 40% cement by - pass dust.