IMPACT OF SELECTED CHEMICAL ADDITIVES ON PERFORMANCE BEHAVIOR OF WARM ASPHALT CONCRETE MIX
Last modified: 2017-02-28
Warm mix asphalts are becoming a regular group of mixtures used in pavement structures in many European countries. Nevertheless there are still a lot of mind barriers which disallow a more distinctive use of this type of mixes especially with respect to improved healthy conditions for road workers and because of potential energy savings during mixing of such asphalt mixture. In parallel there are still ambiguities about possible weaknesses with respect to durability or cracking resistance. Last but not least the actual market offers quite large variety of different additives which needs suitable comparison and proof of real benefits of particular additives. Within the experimental study done as part of ongoing research at the Czech Technical University in Prague different chemical additives have been used representing synthetic waxes or surfactants, as well as comparing them with ready-to-use binders offered by some producers. Besides set of performance testing evaluated on binders a regular
asphalt concrete mix of 0-11mm grading has been designed. For each type of additive used in 50/70 distilled bitumen assessment has been done to determine the appropriate reduced manufacturing temperature at which later test specimens have been produced. In general for most of the used additives the manufacturing temperature was reduced by 20-30°C. On the mixes traditional as well as performance based characteristics have been evaluated and compared. Gained results are presented in the paper.
warm asphalt mix, low-viscosity binders, waxes, tensides, dynamic viscosity, durability, permanent deformations, crack propagation, flexural strength