Strength of bonded anchors in concrete in direct tension

Abstract

Bonded anchors are being used in several civil engineering applications, whose performance needs to be investigated. This paper discusses the experimental investigations made on the strength and failure modes of bonded anchors in concrete. The effect of strength of concrete, embedment length and diameter of anchors has been studied. The important parameters influencing the strength of anchorage system are compressive strength of concrete and the embedment depth of anchors. Three strengths of concretes namely 45 MPa, 52MPa and 52MPa were used along with three embedment lengths of 50mm, 100mm and 150mm. It has been observed that concrete cone failure was predominant in all the specimens. The anchorage strength increases as the compressive strength of concrete increases. As the embedment length of anchor increases, the anchorage strength also increases. The diameter of the anchor does show much influence on the strength of anchorage. The strength of bonded anchors was observed to coincide with the strength estimated as per both CCD design method and ACI 349 method. Bonded anchor load carrying capacity has been observed to closely match with that of the post-installed anchors.