We are a team of experts, dedicated to supporting project owners, engineers, and contractors from the project’s conceptual phase to detailed design, documentations, and valued engineering. Our commitment extends to practical training and on-site support, ensuring successful project completion. We also offer project specific solutions and optional inspection and maintenance services. Based on our extensive experience in structural strengthening, we guaranteed quality and optimal solutions for your projects. Furthermore, our global partners, who are trained and qualified by us, are empowered to utilize our products worldwide

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A very wide spectrum of applications

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Post-tensioning Systems


The CarboStress system by StressHead uses external post-tensioning, employing a carbon fiber reinforced polymer (CFRP) tendon and two anchors. These anchors concentrate force at the plate ends, transferring it into the structure.

Our system includes a fixed anchor and a post-tensioning anchor. The fixed anchor secures one tendon end, while the post-tensioning anchor, operated by a hydraulic cylinder, tensions the opposite end. To suit diverse needs, we offer standard and customized anchors.

For enhanced durability, strength, and stiffness, the CFRP tendon can be bonded to the surface or shielded by, for example, a metal cover to prevent mechanical damage.

  • Bridge strengthening
  • Earthquake strengthening
  • Building strengthening
  • Circular strengthening
  • Easy to install
  • Lightweight
  • Low space requirements
  • Non-corrosive and chemical resistant
  • Concentrated transfer of force at the plate ends
  • Outstanding long-term behavior – no creep and slip behavior
  • Can be applied under operational conditions
  • Maintenance free
  • StressHead CarboStress® head:
  • Material: Carbon fiber reinforced polymer (CRFP)
  • Tensioning force: PP0 = 220kN
  • Anchored force: FSpk,min = 300kN
  • Sika® CarboDur® S626 CFRP plate:
  • Material properties: Elastic
  • Post-tension at time t=0: σPo = 1’410 N/mm
  • Post-strain at time t=0: ƐPo = 8.5 ‰
  • Tensile strength: ftk ≥ 2’800 N/mm
  • Longitudinal modulus of plate: ≥ 165’000 N/mm

StressHead® CL-RESTRAP is an external post-tensioning system made of carbon fiber reinforced polymer (CFRP) tapes that are wound endlessly into a loop. The use of thin, multilayer tapes allows very small bending radii. The loops can be produced in any length and dimension, have excellent long-term behavior and are easy to assemble by hand due to their feather-light weight.

  • Shear strengthening of beams and joists
  • External post-tensioning of circular structures (E.g. water tanks and silos)
  • Outstanding material behavior related to fatigue and relaxation
  • Large tensioning-elongation (εP0≈ 6.3‰), small tensioning losses with concrete creep
  • Active tensioning system simple calculation
  • Feather-light system
  • Easy handling and installation
  • Low space requirement
  • No corrosion and chemical resistant
  • Loop dimension variable

A standard CL-RESTRAP loop is designated according to its post-tensioning force. The associated ultimate loads and post-tensioning forces are defined in the table below. It should be noted that the posttensioning force can be doubled in the case of shear reinforcement due to both-sided installation.

The posttensioning system is tensioned like a tension belt around the element to be reinforced. In the case of small radii, it is pulled around deflection saddles. Bolts are placed in the ends of the loops, which are tightened and locked using hydraulic clamping pliers. The loop is thereby pretensioned.


StressHead Ltd regularly conducts roadshows and presentations directly in your office. If you are interested, please contact 

We are also happy to arrange individual installation demonstrations for small groups, companies or universities on request. Do not delay, put in your request today.

Installation demonstration locations:

  • Schlieren ZH, Reitmenstrasse 7 (CH)