Nowadays, one of the major objectives for pavement management is the improvement of road safety through adequate maintenance and rehabilitation activities. Pavement surface characteristics play an important role in accident occurring, especially in wet conditions: the optimization of surface performance starting from hot mix asphalt (HMA) mix design phases is a fundamental requirement in road construction techniques. Compaction efforts, type of compaction and thickness of asphalt layer are the most relevant factors that influence pavement surface texture. Compaction aims to reduce air voids content and to optimize the granular skeleton in the mix; therefore also surface texture is affected by compaction and by the actual arrangement of the asphalt binder-aggregate matrix at the end of compaction. The compaction method influences the material behavior and the resulting difference in surface performance. The study focuses on the volumetric analysis of laboratory samples in order to verify the influence of different compaction techniques on the specimens homogeneity in terms of air voids distribution. The influence of different compaction techniques on surface texture of laboratory specimens was investigated, too. Two laboratory compaction devices, Gyratory Compaction (GC) and Unical Slab Roller Compactor (USRC) were used in this research to produce lab samples. Mixtures with aggregate of different nature (basalt and limestone) were selected. Gyratory specimens were compacted at different energy levels. Slabs were compacted at the same bulk density levels estimated from the gyratory samples. Typical laboratory tests were performed on the specimens: Air-void content and bulk density were used to determine the mixes volumetric properties whereas samples surface texture was analyzed using a laser profilometer. The relationship between surface texture, air voids content and bulk density was investigated. Outcomes of this study are expected to benefit both practitioners and researchers.
HMA FRICTION COURSE: VOLUMETRIC PROPERTIES VS SURFACE TEXTURE
VAIANA, Rosolino;
2012-01-01
Abstract
Nowadays, one of the major objectives for pavement management is the improvement of road safety through adequate maintenance and rehabilitation activities. Pavement surface characteristics play an important role in accident occurring, especially in wet conditions: the optimization of surface performance starting from hot mix asphalt (HMA) mix design phases is a fundamental requirement in road construction techniques. Compaction efforts, type of compaction and thickness of asphalt layer are the most relevant factors that influence pavement surface texture. Compaction aims to reduce air voids content and to optimize the granular skeleton in the mix; therefore also surface texture is affected by compaction and by the actual arrangement of the asphalt binder-aggregate matrix at the end of compaction. The compaction method influences the material behavior and the resulting difference in surface performance. The study focuses on the volumetric analysis of laboratory samples in order to verify the influence of different compaction techniques on the specimens homogeneity in terms of air voids distribution. The influence of different compaction techniques on surface texture of laboratory specimens was investigated, too. Two laboratory compaction devices, Gyratory Compaction (GC) and Unical Slab Roller Compactor (USRC) were used in this research to produce lab samples. Mixtures with aggregate of different nature (basalt and limestone) were selected. Gyratory specimens were compacted at different energy levels. Slabs were compacted at the same bulk density levels estimated from the gyratory samples. Typical laboratory tests were performed on the specimens: Air-void content and bulk density were used to determine the mixes volumetric properties whereas samples surface texture was analyzed using a laser profilometer. The relationship between surface texture, air voids content and bulk density was investigated. Outcomes of this study are expected to benefit both practitioners and researchers.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
