Ahmed Shlash

ORCID Identifier(s)

0009-0003-1582-7836

Graduation Semester and Year

2023

Language

English

Document Type

Thesis

Degree Name

Master of Science in Civil Engineering

Department

Civil Engineering

First Advisor

Raad Azzawi

Abstract

This research investigates the effect of edge on concrete breakout strength within steel fiber reinforced concrete (SFRC) under pure tension load. Single and group sets of anchors with high-strength steel-headed studs type (F1554 Grade 105) were cast in place within concrete specimens of different amounts of steel fibers and varied edge distances. Steel fibers were used in three percentages (0%, 0.5%, and 1%) by a weight-volume fraction of the mixture to produce three types of concrete mix designs in the lab. The physical and mechanical properties of steel fibers concrete were calculated and measured by testing specimens at the Civil Engineering Laboratory Building (CELB). In total, nine-cylinder specimens of 4-inch diameter and 8-inch height for compressive strength, nine-cylinder specimens of 6-inch diameter and 12-inch height for split tensile test, and nine beam specimens of 6*6*20 inch for modulus of rupture and flexural behavior. Nine concrete pedestals of 2.5*7.5*20 connected to three concrete beams of 7.5*9*55, nine concrete pedestals of 5*10*20 connected to three concrete beams of 10*9*55, nine concrete pedestals of 7.5*12.5*20 connected to three concrete beams of 12.5*9*55 were cast-in-place with 27 sets of anchor groups and 27 of single anchor were installed and tested after 28 days of curing. The two factors of embedment depth and distance between anchors for all sets are kept constant without changing. The adequate embedment depth and the spacing between two anchors in grouping action are followed as specified and defined clearly in ACI 318-19. The experiments revealed that the increase of the amount of the steel fiber fraction increases the concrete breakout strength of anchor group in tension by (14.3%, 3.43%, and 8.21 %) corresponding to the change in edge distance (0.5 hef, 1 hef, and 1.5 hef) respectively for increasing of steel fiber from (0%-0.5%) and (44.88%, 33.3%, and 14.28%) corresponding to the change in edge distance (0.5 hef, 1 hef, and 1.5 hef) respectively for increasing (0%-1%). In the case of a single anchor, the concrete breakout increasing of increasing steel fiber fraction from (0.0%-0.5%) is (1.92%, 1.12 %, and 1.1%) corresponding to the change in edge distance (0.5 hef, 1 hef, and 1.5 hef) respectively. The increase from (0.0%-1.0% SFRC) is (6.76%, 16.6%, and 1.4%) corresponding to the change in edge distance (0.5 hef, 1 hef, and 1.5 hef), respectively. Also, the increase in steel fiber from (0.0%-0.5%) of the anchor group is causing an increase in strain around (+1.58%, +19.37%, and +1.89%) and displacement approximately (+25. 39%, +7.95%, and +22.33%) corresponding to the change in edge distance (0.5 hef, 1 hef, and 1.5 hef) respectively. The increase in steel fiber from (0.0%-1.0%) is causing an increase in strain around (+46.0%, +65.16%, and +11.79%) and displacement approximately (+49.21%, +15.91%, and 40.77%) corresponding to the change in edge distance (0.5 hef, 1 hef, and 1.5 hef) respectively. Similarly, the increase in steel fiber of single anchor from (0.0%-0.5%) is causing the rise in displacement around (+39. 73%, +56.86%, and +44.38%) corresponding to the change in edge distance (0.5 hef, 1 hef, and 1.5 hef) respectively. The increase in steel fiber from (0.0%-1.0%) is causing the rise in displacement around (+56.76%, +76.47%, and 68.75%) corresponding to the change in edge distance (0.5 hef, 1 hef, and 1.5 hef) respectively. The concrete breakout strengths for single and group anchors were compared and tested in the same conditions. The concrete breakout strength of the group anchors effect will differ by increasing steel fiber from (0.0%, 0.5%, and 1.0%). The differences are (+63.74%, +86.5%, +89.21%, +72.5%, +88.5%, +95.48%, +86.5%, +98.92%, and +100.0%) respectively, and corresponding to (0.5 hef, 1 hef, and 1.5 hef). Concrete average compressive strength increased by increasing steel fiber. The growth in the average strength from (0.0% -0.5%) is (3.04%) and the increase from (0.0% - 1.0%) is (9.62%). The split tensile strength increased by increasing the steel fiber. The rise of tensile strength from (0.0%-0.5% SFRC) is (9.05%) while the increase of strength from (0.0%-1.0% SFRC) is around (10.67%). The flexural strength increased by increasing the steel fiber. The rise of steel fibers by (0.5% and 1.0%) led to increased flexural strength by (9.5% and 38.5%) respectively. Finally, compare the experimental results of the concrete breakout strength with the modified Concrete Capacity Design Method (CCD).

Keywords

Anchor bolts, Pullout, Edge distances, Steel fibers, Group effects, Concrete capacity design, Embedded depths, Tension loads

Disciplines

Civil and Environmental Engineering | Civil Engineering | Engineering

Comments

Degree granted by The University of Texas at Arlington

Download

Share

COinS