Projects

Durability cracking in asphalt pavements is a major deterioration mechanism for asphalt concrete (AC) pavements in areas experiencing temperature and precipitation extremes. In this study, we develop a case study example of thermal and durability cracks widely observed in the Southwest of the United States. Significant factors and root causes influencing occurrences of thermal durability cracks are presented using data compiled from forensic investigation of sites, field core characterization, and mechanistic assessment of the conventional flexible pavement structures.

Field aging of asphalt concrete (AC) mixtures is a complex phenomenon resulting in significant changes in the rheological properties and chemistry of binders and impacting key performance characteristics of asphalt mixtures. Laboratory simulation of the field aging characteristics of asphalt concrete (AC) mixes is essential in characterizing its long-term performance. Hence, long-term aging protocols have become a key part of the Balanced Mix Design (BMD) framework adopted by many state and local agencies.

Although cracking resistance research has been carried out extensively in other states, a large amount of the work is not immediately applicable to Arizona, where the climate is substantially more extreme both in heat and in cold than in many other parts of the country.
The main goal of this is to develop a balanced mix design framework that can be used in diverse climatic regions and develop a better understanding of fracture behavior of polymer-modified mixes. 

The in-place density of asphalt pavements is a key indicator of construction quality, durability, and long-term performance. Pavement construction requires coordination and monitoring to ensure proper compaction which in turn achieves the targeted in-place density. Two major factors hindering targeted in-place density are uniform mat temperature and uniform rolling pattern. The objective of this study is to develop an automated monitoring protocol with the use of aerial images using the uncrewed aerial vehicle (UAV).

Fiber reinforcement is considered to improve the cracking resistance of asphalt concrete (AC). Fibers can delay crack propagation and improve fracture resistance through various crack-bridging mechanisms.
The main goal of this study is to investigate the cracking performance of Fiber Reinforced Asphalt Concrete (FRAC) based on comprehensive fracture characterization performed through a series of monotonic and fatigue fracture types of experiments.


 

Reflective cracking in hot-mix asphalt (HMA) laid over existing jointed concrete airfield and highway pavements is considered a major pavement distress. Reflective cracking mechanisms are complex due to intertwined effects of temperature and vehicular loading conditions causing intensified stresses in overlays.
The proposed study presents an HMA overlay thickness design model for reflective crack growth.

Automation technology offers numerous advantages to the trucking industry in terms of fuel savings, operational efficiencies and preventing fatal crashes. Truck spacing is one of the key parameters of a truck platoon that can be optimized to balance fuel savings and impact to the pavements. The rest period defining the duration between the loading applications from two consecutive trucks can impact permanent deformations and fatigue cracking in asphalt pavements.
The main challenge with this new type of loading scenario is the uncertainty of the stress state configurations that may be generated during the loading phase of the platoons. 

Pavements and roofs play an essential role in shaping the urban microclimate, affecting energy balance, and contributing to the so-called Urban Heat Island (UHI) effect. UHIs phenomenon appears to be one of the main contributing causes for the increase in Building Energy Demand (BED) and adverse health conditions.
Main goal of this research is to quantify the benefits and tradeoffs of cool pavement technologies used in urban areas using validated computational models.

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