Advancements in research and development

The past 100 years have witnessed several innovative and creative improvements and developments in the field of highways and pavements. Improved safety, efficient operations and high quality roads have been the mark of the past Century. However, in spite of investing time and resources to build paved roads that will meet their design objectives, early failures and premature deteriorated surfaces have been commonly observed worldwide. Several major research initiatives such as USA SHRP were lunched to address old problems that are still unsolved today such as reflection cracking, rutting, stripping and other similar pavement problems. Unfortunately, after more than 10 years since the start of the SHRP initiative same problems are still observed on many highways in the world today. One of the main deficiencies in many of the current research approaches is their assumption that "newly constructed asphalt pavements are structurally sound". Subsequently, all attempts to treat and correct any problems or failures observed on the roads are related to causes and factors that may exist only after completion of the construction of the road. In other words, the solutions are mainly materials based and therefore modifications of the designs of the asphalt mixes as well as selection of different materials have been the main and only available course of action. Clearly, this approach neglects the fact that the construction process contributes to the main assumption of the current analytical approach. If the construction of asphalt pavements is shown to be flawed then the stated assumption may be questionable. This paper gives a brief background of historical problems associated with asphalt pavements; discusses its traditional approaches and remedies. Also, a new innovative approach is presented which focuses on the interaction between the newly laid soft asphalt layer and the stiff steel drum during the compaction of the asphalt mat. The new approach shows that defects are created during compaction which causes the premature deterioration and early failure of the newly constructed roads. A new roller (AMIR) has been developed and tested in several countries including Egypt, Canada, Sweden and Australia. The results of the field tests and evaluation of the implementation of this new technology is presented and discussed.