Shear strength of epoxy anchors embedded into low strength concrete

► Cyclic shear tests were conducted on anchors embedded to low strength concrete. ► The obtained results indicate that increasing the anchor diameter have decreased the shear strength. ► A decrease in shear capacity was observed for lower concrete strengths. ► A reduction factor is introduced depending on the bar diameter and concrete strength. ► Establishing an upper limit for the anchor bar diameter in the related standards is proposed. Chemical anchors are getting more frequently used to connect structural elements. The studies regarding the chemical anchors embedded in low strength concrete are very limited in the literature. However, the compressive strength of the concrete may be 10MPa or lower in many strengthening applications. Steel bars having 12, 16 and 20mm diameters have been selected as the anchor rod in this study. They have been embedded in to concrete blocks with 5.9 and 10.9MPa compressive strength. Solvent-free epoxy based three component chemical adhesive has been used for the connection between concrete and anchor bar. The depth of holes is 10, 15 and 20 times that of the anchor diameter. The anchors have been embedded such that they are sufficiently away from the free edge so as not to cause any concrete failure. The load–displacement cycles of all anchors have been obtained by reversed cyclic tests with incremental displacement. The obtained results indicate that increasing the anchor diameter have decreased the shear strength. Even though the anchor damage has been caused by steel failure, a decrease in shear capacity was observed with the lower strength concrete.