It is well known that the performance of hot mix asphalt (HMA) in service life is closely related to a proper aggregate gradation. A laboratory study was conducted to investigate the effects of nominal maximum aggregate size (NMAS) on the performance of stone matrix asphalt (SMA). The volumetric characteristics and performance properties obtained from wheel tracking tests, permeability test, be...

The 26 sample sites in 7 study plots adjacent to asphalt road and earth road in coastal wetland in the Yellow River Delta were selected to quantify plant diversity using quadrat sampling method in plant bloom phase of July and August 2012. The indice of β T and Jaccard's coefficient were applied to evaluate the species diversity. The results showed that the plant diversities and alien plants we...

The permanent deformation pavement of roads and streets at tropical zones Abstract (if layers are sufficiently compacted) is due to increase of asphalt layers temperature and consequential decrease of modulus of elasticity. Therefore, the asphalt mixture moves aside of the wheels of heavy vehicles and cause permanent deformations without volume variation. On the other hand, if the asphalt layer...

1190 www.thelancet.com/oncology Vol 12 December 2011 In October, 2011, 16 experts from nine countries met at the International Agency for Research on Cancer (IARC) in Lyon, France, to reassess the carcinogenicity of bitumens and their emissions, and of some N-heterocyclic and S-heterocyclic polycyclic aromatic hydrocarbons (PAHs). These assessments will be published as Volume 103 of the IARC Mo...

We conducted a cross-shift study with 66 bitumen-exposed mastic asphalt workers and 49 construction workers without exposure to bitumen. Exposure was assessed using personal monitoring of airborne bitumen exposure, urinary 1-hydroxypyrene (1-OHP), and the sum of 1-, 2 + 9-,3-,4-hydroxyphenanthrene (OHPH). Genotoxic effects in WBC were determined with nonspecific DNA adduct levels of 8-oxo-7,8-d...

In recent decades, economic development and population growth in the world has led to the expansion of road networks. Therefore the use of optimum methods for repairing and maintenance of these roads is considered as an important value. Today one of the options in this regard, is the use of asphalt recycling technology. The present study which took place in the summer of 2015 in Iran, Lorestan ...

Pavement surface texture and its skid resistance are two key safety parameters of highways, which both are influenced by pavement characteristics. This research is done on a newly constructed asphalt pavement (Qom-Garmsar freeway) in Iran. The goal is investigating the relation between skid resistance and pavement texture in order to asphalt content changes in Hot Mix Asphalt. Mean Texture Dept...

The present experimental research investigates the feasibility of partial substitution of styrene-butadiene-styrene (SBS) with ground granulated blast-furnace slag (GGBS) for the modification of bitumen and porous asphalt mixtures. The control asphalt mixture and the seven modified porous asphalt mixtures have been analyzed separately and their performance was compared. Modified bitumen and asp...

By measuring the spectral reflection from the four different road conditions dry, wet, icy, and snowy asphalt, a method of classification for the different surfaces--using two and three wavelengths--is developed. The method is tested against measurements to ascertain the probability of wrong classification between the surfaces. From the angular spectral response, the fact that asphalt and snow ...

Asphalt modification/reinforcement has received considerable attention as viable solutions to enhance flexible pavement performance. This is mainly prompted by the unsatisfactory performance of traditional road materials exposed to dramatic increases and changes in traffic patterns. This paper presents the evaluation of fatigue behaviour of nano reinforced Stone Mastic Asphalt mixtures. Fatigue...