EXPERIMENTAL INVESTIGATION OF CONCRETE BREAKOUT STRENGTH OF ANCHOR IN TENSION WITHIN FIBER REINFORCED CONCRETE

Abstract

This research investigates the effects of steel fibers on the concrete breakout of the cast-in-place headed stud anchors in tension. High strength anchors (F1554 G105) is used in this study for varying steel fiber dosage of 0.0%, 0.5% and 1.0% by volume fraction of concrete. The physical properties of steel fiber reinforced concrete were calculated through various test at the Civil Engineering laboratory Building. In total, 9-cylinder specimens of 4” diameter and 8” height, and 9 beam specimens, 6”x6”x20” were made and tested. After 28 days of curing, the specimens were tested for their compressive strength and modulus of rupture, as well as 9-cylinder specimens of 6” diameter and 12” height to test for split tensile test. Nine headed stud anchors were installed and tested in the various mixtures. The depth of anchor embedment is kept constant, and the spacing between anchors is specified as per ACI 318-14. No grouping action was found. CCD method (ACI 318-14) is modified in order to predict the concrete breakout capacity of the cast-in-place anchor. The experiment revealed that the increase in dosage of fiber fraction increases the compressive strength of the concrete by 35% and 48% for 0.5% and 1% respectively from normal weight concrete without steel fibers. The breakout strength of concrete in tension increased by 77% for 0.5% volume fraction of steel fiber in concrete and increased 107% for 1.0% volume fractions of steel fiber in concrete in comparison with 0.0% Steel fiber reinforced concrete. It is found that the diameter of cone of concrete reduced as the dosage of steel fibers increased and the failure angle increased as the dosage of steel fibers increased.