stiffback

strongback

A frame attached to the back of a concrete form to stiffen or reinforce it.
References in periodicals archive ?
Durham, again missing Chris Rushworth with a stiffback, mixed it up at the start and in the fourth over they hit the jackpot, Usman Arshad, their fourth bowler used, taking 1-1 as the new Chester-le-Street floodlights started to take real effect.
If Gerry had the endurance to sit past sunset in my father's stiffback chair I had misjudged him.
We would hammer into the existing rock tunnel and put stiffbacks to hold the panels from shifting either way," Ingersoll explained.