Performance of cast-in anchors in early age concrete with supplementary cementitious materials

This paper investigates the behavior of cast-in headed anchors in early age concrete with different mixes and supplementary cementitious materials. A series of anchor pull-out tests of cast-in headed anchors were conducted using slag and fly ash as Supplementary Cementitious Materials (SCMs) and their amounts were varied from 0 to 50% for slag and 0 to 25% for fly ash of total cement content in concrete. The tests were conducted from 18 h to 28 days after concrete being casted. The results from the experiment were compared with the current theoretical model used in literatures and design standards to predict concrete cone failure for mature concrete to check their applicability for early age concrete with SCMs. Further, a comprehensive 3D finite element model was developed and verified against experimental results. The verified finite element model was used to conduct detailed parametric studies varying concrete and anchor properties. A detailed discussion on the anchorage behavior with different types and amount of SCMs based on findings of this study is presented in this paper. The concrete cone capacity method was found to be applicable for early age concrete with headed anchor with 40 mm effective depth and concrete strength as low as 3 MPa for anchors tested in this study.