Current Research
Evaluate the Importance of Fine Aggregates in Achieving Adequate Skid Resistance in TxDOT Hot Mix Asphalt Mixtures
tEXAS DEPARTMENT OF TRANSPORTATION (TXdot)
Figure 1: Three-wheel polishing and dynamic friction test devicesThe lack of skid resistance has been an important issue for TxDOT pavement as many of them cannot hold adequate skid resistance in the long run, and even some newly constructed roads are observed to have poor skid resistance. The main focus of the study is understanding the effects of fine aggregates and fines on the skid resistance of asphalt concrete since their impacts on the skid resistance and performance are not well understood. Through extensive study with a controlled asphalt mixture, the performing agency examined the effects of various asphalt mixture parameters on frictional performance. The study results revealed that aggregate portion in asphalt mixture gradation passing No. 04 and retained on No. 30 controls the mixture frictional performance due to its higher surface area. Although aggregates smaller than No. 30 sieve size have a higher surface area, the study results indicated that their effect on frictional performance is less significant. These study findings were verified in various TxDOT asphalt mixtures. The study is currently underway for field implementation and performance verification of asphalt mixtures frictional performance through test sections constructions in the state of Texas.
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Figure 2: Surface area of various portions of aggregate gradationPrincipal Investigators:
Imad Abdallah
Soheil Nazarian
Award Duration:
2021 - 2026
Figure 3: Typical friction deterioration curve of asphalt mixtureBudget:
$863,000
