Tensile Capacity of Short Headed Anchor Bolts Embedded in High Strength Fibrous Concrete

摘要

This investigation studied the effect of steel fibres on the pull out capacity of short- headed anchor bolts embedded in high strength concrete. The studied variables in experimental programme included testing short headed anchors embedded in 72 pull-out specimens, with three embedment depths (25, 37.5, and 50 mm), three compressive strengths (45, 53, and 58 MPa), four steel fibres volume percentages (0.0, 0.4, 0.8, 1.2) and two anchor diameters (10, and 12 mm). The steel fibres used were of the shelled type (Harex) with irregular cross-section type with an aspect ratio of 36.34. The test results showed that the embedment depth has the major effect on the pullout capacity. The pullout capacity increases also with the addition of steel fibres and with the square root of the concrete compressive strength, which is an indirect measurement of the tensile strength of concrete. The brittle type of failure of the unreinforced specimens changed to a ductile one with the presence of the steel fibres. For all the specimens, the failure angle ranged between (20-30°) with the horizontal plane.