Concrete overlays on bridge decks are expected to be more durable as compared with the more common asphalt solution. Besides stresses due to traffic load and temperature variations at service, the overlays are exposed to stresses due to long term shrinkage. Of interest is to evaluate the concrete overlay due to the shrinkage induced stresses at the composite interface. Three strategies have bee...

MUN, SUNGHO. Nonlinear Finite Element Analysis of Pavements and Its Application to Performance Evaluation. (Under the direction of Dr. Y. Richard Kim and Dr. Murthy N. Guddati.) This research documents the findings from the study of failure mechanisms of fatigue cracking in asphalt pavements using the finite element program that employs the viscoelastic continuum damage model for asphalt layer ...

The performance of asphaltic pavements during their service life is highly dependent on the mechanical properties of the asphaltic layers. Therefore, in order to extend their service life, scientists and engineers are constantly trying to improve the mechanical properties of the asphaltic mixtures. One common method of improving the performance of asphaltic mixtures is using different types of ...

Compound motion of double-tamper mechanism causes an impact force on the frame of flatiron-box, which affects the quality of the load when the asphalt paver is running. Different from the previous simplified model, in this paper, the double-tamper mechanism with two parallel slider-cranks is considered. According to the analysis of the structure and principle of the mechanism, and considering t...

The asphalt paving industries are faced with two major problems. These two important challenges are generated with an increase in demand for environmentally friendly paving mixtures and the problem of rapidly rising raw materials. Recycling of reclaimed asphalt pavement (RAP) is a critical necessity to save precious aggregates and reduce the use of costly bitumen. Warm Mix Asphalt (WMA) technol...

This paper describes the effects of reinforcement by randomly distributed nylon fibers and addition of nanoclay on some engineering properties of a typical asphalt concrete. The properties of asphalt concrete reinforced by different percentages of 25 mm nylon fibers have been compared with those of the mixtures containing different percentages of nanoclay and those in which both the fibers and ...

Various forms of asphalt pavement distress, such as rutting, shoving, and bleeding, can be attributed, in many cases, to low air voids in the mixtures during production and placement. The occurrence of low air void contents during plant production may originate as a result of an accidental increase in binder content or mix fines (or both). When low air voids are encountered during production, t...

Leaking underground storage tanks (USTs) containing gasoline represent a significant public health hazard. Virtually undetectable to the UST owner, gasoline leaks can contaminate groundwater supplies. In order to develop remediation plans one must know the extent of gasoline contamination. Centrifugal simulations showed that in silty and sandy soils gasoline moved due to the physical process of...

Document summarizes a procedure to establish pay factors for asphalt concrete pavement construction using performance models for fatigue and rutting based on the analysis of accelerated pavement tests from the Caltrans Heavy Vehicle Simulator (HVS) and the WesTrack accelerated pavement performance test program. Results of the performance-based approach are compared with pay factors determined b...