Study on the bond behavior of high-strength geopolymer concrete: Fid-Bau Portal

Study on the bond behavior of high-strength geopolymer concrete

Padakanti, Rakesh / Sarella, Venkateswara Rao / Pancharathi, Rathish Kumar / Jha, Ankush

Geopolymer Concrete (GPC) is an evolving construction material well known for its environmental benefits derived from different aluminosilicate sources. However, fly ash-based geopolymer concrete normally requires thermal treatment for curing to attain compressive strength that again leads to increasing in the carbon footprint and manufacturing cost. Added to this, developing high-strength geopolymer concrete is more challenging. This paper explored ambient temperature cured high-strength geopolymer concrete using different aluminosilicate sources. One important parameter which needs special attention in the high-strength concrete is bond behavior, as it requires perfect transfer of forces from steel to concrete and maintaining strain compatibility. In this study, Particle packing model was used for aggregate optimization to have dense and compact mix. Blended high-strength geopolymer concrete attained compressive strength 93 MPa at 28 days under ambient temperature curing. The bond behavior of such a high-strength geopolymer concrete was studied considering the various parameters that influence grade of concrete, bar diameter and change in embedment length. Numerical modeling of the pull-out and beam end specimens was simulated using ATENA-GiD. It was hammered out that with increase in the grade of geopolymer concrete, there is an increase in the maximum bond stress; while with increase in the bar diameter and embedment length, there is a decrease in the maximum bond stress. An equation to predict the maximum bond stress for high-strength GPC is proposed based on multiple non-linear statistical analysis and compared with the equation proposed in ACI code.

Graphical abstract