Innovative Strengthening of a Damaged Column Head near Paris

In a supermarket close to Paris, engineers discovered severe cracks and spalling at a column head (capital). The structural capacity was compromised, and urgent strengthening was required to prevent further damage and ensure safety.

The Problem:

• Cracked concrete made bonded reinforcement plates ineffective.

• The system needed to actively confine the column, close existing cracks,

  and restore load capacity sustainably.

• Tight construction space ruled out traditional post-tensioned steel bars.

The Solution: CL-RESTRAP
The engineering firm Savae selected Carbo-Link’s CL-RESTRAP system — a high-strength CFRP strap with active post-tensioning.

• Custom straps and deviation saddles were manufactured to match the measured perimeter.

• Technicians received targeted on-site training for proper stressing tool use.

• Despite limited access, the lightweight strap was easily threaded through a narrow gap and post-tensioned horizontally with 8 t load.

The Result:

• Cracks visibly closed.

• The column’s capacity was restored within minutes.

• The supermarket was able to safely resume operations.

“We were thoroughly impressed by the system. Other engineers had told us it couldn’t be done. With CL-RESTRAP, we managed not only to close the cracks, but also to thread the strap through a very narrow opening. The installation was straightforward, and the prestressing process was completed within minutes.”
— Ludovic Moreno, Lead Engineer at Savae

Key Benefits of CL-RESTRAP:

• Active confinement & crack closure

• Reliable strengthening in confined spaces

• Rapid and straightforward installation

• Durable, sustainable solution

This project shows how CFRP post-tensioning can succeed where conventional techniques reach their limits.