Title:
Influence of Concrete Material Ductility on Headed Anchor Pullout Performance
Author(s):
Shunzhi Qian and Victor C. Li
Publication:
Materials Journal
Volume:
106
Issue:
1
Appears on pages(s):
72-81
Keywords:
anchor; connections; ductility; engineered cementitious composites; pullout; structural capacity
DOI:
10.14359/56319
Date:
1/1/2009
Abstract:
While steel anchors are widely used in the construction industry, the fracture failure problem of anchor/concrete connections associated with the inherent brittleness of concrete has not been fully resolved. In this paper, the influence of material ductility on the anchor pullout performance is systematically investigated by replacing normal concrete with a relatively new ductile concrete material - engineered cementitious composites (ECC) - that strainhardens to several percent tensile strain capacity (also known as tensile ductility, the maximum tensile strain a material can sustain before load drop due to fracture failure). The experimental results show that anchor/ECC connections exhibit a more ductile failure mode, a higher ultimate strength, a higher displacement capacity, and a higher energy absorption compared with connections with regular concrete materials. The cone-shaped brittle fracture mode typically observed in concrete materials is replaced by distributed inelastic damage in the form of microcracking over a volume of material near the anchor heads. This significant enhancement of ductility suggests that the use of ECC material can be very effective in redistributing loads among anchors in a group, resulting in improved load response of steel anchor connections.