University Events

Description: Mechanical Engineering MS Thesis Defense by
Mr. Vinh T. Nguyen

December 23, 2015

2:00 p.m. - 4:00 p.m.

Textile Building, Room 101E Conference Room

TOPIC:
Design and Analysis of Embedded Pipe Network and Conducting Spreader Layer in Asphalt Pavement to Reduce Common Pavement Failures in Hot and Cold Climates and to Harvest Energy


ABSTRACT:
Pavements are one of the primary modes of everyday transportation in every country in the world. According to the National Asphalt Pavement Association, the United States alone has more than 2.6 million miles of paved roads and highways, and 93 percent of those are paved with asphalt. The asphalt material has very high absorptivity and low emissivity causing asphalt pavements to absorb solar radiation from the sun and rise in temperature in hot climates. The raising in temperature causes asphalt pavements to become softer and more susceptible to permanent deformation, also known of as rutting, under traffic. After rising in temperature, the pavements can also release the stored energy to their surroundings causing the nearby air and building temperature to increase. This phenomenon is referred to as the Urban Heat Island Effect (UHIE), which highly reduces the air quality and increase electricity usage from nearby buildings. In moderate and cold climates, thermal cracking of asphalt pavements is responsible for costly annual maintenance and rehabilitation. There are two popular types of thermal cracking: low temperature cracking and thermal fatigue cracking. Low temperature cracking mostly appears when the thermal stress developed exceeds the tensile strength of the asphalt mixture. However, if the thermal stress developed is below the asphalt mixture tensile strength, pavement failure may still occurs due to repetitive thermal cyclic loads. This type of pavement failure has been widely proposed by many researches to be a potential mode of pavement distress in moderate climate where the daily temperatures highly fluctuate. Previous research by our group and others have found that a spreader layer made of highly thermal conductive material coupled with a pipe network can act as an adequate sink for the pavement and lower the surface temperature significantly for hot climates to reduce rutting. In this study we have theoretically investigated the performance and behaviors of the asphalt pavement coupled with the pipe-spreader system under realistic environmental conditions. The results obtained from this research have shown that adding the highly conductive spreader layer to a pipe network helps reducing both the surface temperature and rut depth (by 6 mm after 5000 load repetitions) while still maintaining large pipe spacing value to minimize structural risks. It has also been discovered that the thermally induced tensile stress at the pavement surface was reduced significantly (by at least 80%) with the help of the pipe-spreader system. The thermal energy collected from the pavement was also investigated as an energy source to power two different absorption refrigeration cycles (Amonia-water absorption refrigeration cycle and Lithium-Bromide absorption refrigeration cycle) to provide cooling of nearby residential buildings. The results in this research indicate that the thermal energy obtained by the collector system is not enough to power the absorption refrigeration cycles and additional energy input is needed to provide adequate cooling. Thus, the cost of implementing and maintaining this system would be quite high. However, this system is very promising to pay for itself in the long run.

THESIS ADVISOR:
Dr. Sankha Bhowmick

THESIS COMMITTEE:
Dr. Sankha Bhowmick, Dr. Mehdi Raessi, Dr. Rajib Mallick

Open to the public. All MNE students are encouraged to attend.

For more information, please contact Dr. Sankha Bhowmick (sbhowmick@umassd.edu, 508-999-8619).


Thank you,

Sue Cunha, Administrative Assistant
scunha@umassd.edu
508-999-8492