Graduation Semester and Year




Document Type


Degree Name

Master of Science in Civil Engineering


Civil Engineering

First Advisor

Raad Azzawi


This study investigates the effects of Polypropylene fibers on the concrete breakout of post-installed screw anchor bolts. Concrete anchors were installed within concrete specimens of differing amounts of Polypropylene fibers. Four differing mixtures were produced using, 0, 0.5, 1, and 1.5% fibers by volume of the mixture. Their physical properties were calculated through testing at the Civil Engineering Laboratory Building (CELB). In total, 16 cylindrical specimens, 4” in diameter and 8” in height, and 6 beam specimens, 6”x6”x20” were produced and tested. After 28 days of curing, the specimens were tested for their compressive and tensile strengths, as well as their modulus of rupture. Additionally, twenty screw anchors were installed and tested in the varying mixture types. The results of the tests were then analyzed. It was discovered that as the fiber reinforcement approached 1% and over, the compressive strength of the concrete decreased which was attributed to reduced workability and increasing air voids from poor consolidation. Although the compressive strengths of the 1% and 1.5% were reduced, there was a linear trend between the addition of fiber reinforcement and tensile breakout capacity, however the results also showed a relationship between the compressive strength of the concrete and the tensile breakout capacity. Regression analysis was performed and the CCD method modified in order to predict the breakout capacity of a post-installed anchor. In conclusion, the addition of fiber reinforcement will lead to an increase in the breakout capacity of an anchor, while the reduction in compressive strength of a specimen will lead to a decrease in the breakout capacity of an anchor. Due to loss in workability the addition of fibers can also lead to poor consolidation which can lead to a reduction in the compressive strength, and thus a reduction in the breakout capacity of the anchor.


Anchors, Fiber-reinforced concrete


Civil and Environmental Engineering | Civil Engineering | Engineering


Degree granted by The University of Texas at Arlington