Publication Date



Open access

Degree Type


Degree Name

Doctor of Philosophy (PHD)


Civil, Architectural and Environmental Engineering (Engineering)

Date of Defense


First Committee Member

Ronald Zollo - Committee Chair

Second Committee Member

Carol Hays - Committee Member

Third Committee Member

Antonio Nanni - Committee Member

Fourth Committee Member

Brian Metrovich - Committee Member

Fifth Committee Member

Mohamed Fahmy - Committee Member


Fracture mechanics is applied to study the behavior of concrete containing expanded polystyrene (EPS) aggregate replacement. The EPS replaces a portion of the normal weight fine aggregate. Previous research has shown EPS aggregate replacement changes the failure mode in compression from a typical instantaneous failure, as in normal weight concrete (NWC), to a more gradual dissipation of load carrying capacity. This behavior is investigated through the use of fracture mechanics. The fracture energy, critical stress intensity factor and characteristic length of EPS concrete, NWC and fiber reinforced concrete (FRC) are experimentally determined. The two types of tests used to study these properties are the three point bending test recommended by the RILEM technical committee and a wedge splitting test developed recently. The conclusions derived from this research demonstrate that EPS aggregate replacement increases the size of the fracture process zone in front of the crack tip. This increase in size changes the failure mode of concrete allowing it to maintain load after reaching peak load and absorb more energy during the fracture process.


Fracture Mechanics; Concrete; Expanded Polystyrene; Aggregate