Over the past decade, the Texas Department of Transportation (TxDOT) focused research efforts on improving hot mix asphalt concrete (HMAC) mix design to preclude rutting in the early life of pavements. However, these rut-resistant stiff mixtures may be susceptible to long-term fatigue cracking due to oxidative aging. This project completed initial development of an HMAC mixture fatigue design a...

In this paper, the effect of adding recycled glass powder (RGP) as a third component in polymer modified bitumen is studied. RGP and styrene butadiene rubber (SBR) is added to the base bitumen in order to prepare modified binders and mixtures. The initial study is performed to determine physical properties of unmodified, SBR modified and RGP-SBR modified asphalt binders which prove RGP's compat...

The National Center for Asphalt Technology (NCAT) has undertaken a wide range of hot mix asphalt (HMA) related research projects. These projects have been funded by various agencies such as the National Cooperative Highway Research Program (NCHRP) of the Transportation Research Board, the Federal Highway Administration (FHWA), the Alabama Department of Transportation, the South Carolina Departm...

The National Center f’or Asphalt Trchnolofiy (NCAT) has just complctd two Nation;ll Coopwrrive HicThw:tv Rr<e:lrch Pq!ram (NtHR6) Projects: NCHRP 9-X. “Designing Stone Matrix Asphalt (SMA) Mixtures.” and NCHRP 9-9. “Reilnement of Superpave Gyratory Compaction Procedure.” Dr. Ray Brown. NCAT director. was the p r i n c i p a l invcsti:etor on both pmjects. The fint project on SMA represented ;I ...

More than 90% of Malaysian roads are constructed using asphaltic concrete. However, previous investigations of asphaltic concrete have mainly concentrated on the macroscopic properties of the composite materials based on the assumption that the mixtures are homogeneous and isotropic. This paper applies a digital image processing technique to compare the orientations of coarse aggregate particle...

Granite is very widely distributed in the world, but granite an acidic aggregate with poor adhesion to asphalt. In untreated asphalt mixtures, pavement water damage and loose disease are more prominent, affecting service life of level. Enhancing road performance mixture generally improves properties granite. Qingchuan rock asphalt, anti-stripping agent KH5, aliphatic amine AJ-1 two groups compo...

During the process of compaction in Hot-Mix Asphalt (HMA) mixtures, the distance between aggregate particles decreases as they come together and eliminate air-voids. By measuring the inter-particle distances in a cut-section of a HMA sample the degree of compaction can be estimated. For this, a calibration curve is generated by computer simulation technique when the gradation and asphalt conten...