Behavior of reinforced concrete columns confined with prestrained shape memory alloy plates

Abstract EN

External confinement of concrete columns increases the column capacities.

This is essential for deficient columns to restore their named capacity, or for safe columns to enhance their capacities if required.

This paper introduces a simple technique using the superior properties of shape memory alloys (SMA) to actively confine circular concrete columns.

The SMA plates were tensioned prior to confinement and placed in their exact locations.

The temperature change was applied after the plates were placed on the columns, leading the SMA plates to compress the columns.

The experimental program consisted of six circular concrete columns specimens (100 mm diameter, 600mm height).

The parameters studied in the experimental program are the applied tension force to the external stirrups prior to the confinement process, and type of confinement (active or passive).

The increase of the column capacities due the active SMA confinement was observed, as well as the change of the column behavior after active confinement.

Finite element models were performed using ABAQUS software to verify the experimental results.

The paper concluded an increase of (17% -38% ) in the column capacities compared with the unconfined column.

The finite element analysis showed close results to the experiment program, which could lead to a future wide range study to generalize this simple technique on different concrete columns.