Date Approved


Embargo Period


Document Type


Degree Name

PhD Doctor of Philosophy


Civil and Environmental Engineering


Henry M. Rowan College of Engineering


Cheng Zhu, Ph.D., PE

Committee Member 1

Yusuf Mehta, Ph.D., PE

Committee Member 2

William T. Riddell, Ph.D.

Committee Member 3

Gilson R. Lomboy, Ph.D., PE

Committee Member 4

Hamed Seyyedhosseinzadeh, Ph.D.


Cold regions, Extruded Polystyrene (XPS) Boards, Tire Chips, Foamed Glass Aggregates (FGA), Foamed Concrete, pavement insulation




Civil and Environmental Engineering


Pavements in cold regions suffer from additional deterioration due to the influences of extreme climate on frost-susceptible subgrade layers. To address this problem, one efficient strategy is to add a thermal insulating layer above the frost-susceptible layer. This study aims to evaluate the insulating effects of four materials: XPS boards, tire chips, foamed glass aggregates, and foamed concrete. Large-scale insulated pavement boxes (1.2m×1.2m×0.8m) were constructed to compare the thermal performance of different materials. The thermal performance of each box was evaluated and graded based on indicators related to the short-term temperature decrease and long-term temperature variation.

Experimental results show that with the same insulation layer thickness, XPS boards have the best overall performance (65.8/100), followed by foamed glass aggregates (60.1/100), foamed concrete (52.7/100), tire chips (48.8/100), and the control box (38.8/100). Furthermore, finite element method (FEM) models were developed and calibrated to predict the thermo-mechanical coupled performance of insulated pavement structures. Parametric analyses using FEM enable the formulation of a thermally-mechanically balanced insulation pavement design procedure, which can be used to predict the maximum allowable load repetitions under specific local climate conditions. The cost analysis indicates that to achieve equivalent thermal performance in the subgrade layer, using an insulation layer could save approximately $1M/mile in construction cost.