Tunnelling GFRP Solutions

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Tunnelling GFRP Solutions

GFRP Bar & Stirrups

The GFRP BAR and Stirrups are successfully used to replace the traditional reinforcement bar within concrete structures in temporary tunnelling works (D-walls, retaining walls, piles and the like) e.g. within the tunnel breakthrough, the so-called ‘soft-eye’.

The GFRP BAR CRG reinforcement elements are made from reinforced polyester resin matrix, together with a unidirectional Glass Fibre (GFRP type E-Glass) continuous thread profile.

The GFRP BAR CRG provides the following advantages:

– Extremely high tensile strength

– High flexural strength

– High shear strength

– Extremely high modulus

– Significant enhancement of the friction effect (pull-out effect)

– Cuttability

– High corrosion resistance


Used in tunnelling works, Maccaferri GFRP CRG fibreglass bolt is equipped with a steel head for post-tensioning and is used in rock bolting, soil nailing and ground anchors. It is made of a reinforced polyester resin matrix, together with a unidirectional glass fibre (GFRP type E-Glass) continouscontinuous thread profile. The thread process does not affect the glass fibre integrity, withwhile significantly enhancingement of both friction effect (pull-out), and overall tensile strength capacity.

The steel head is sized according to the mechanical performance of the specific profile on which it is installed. The tensioning system is fast and effective and is calibrated to ensure the integrity of the GFR profile.

It is also possible to connect two elements by a S355 steel sleeve.

The GFRP BOLT CRG is recommended for temporary application only (ACI440.1R, refers).


Fibreglass reinforced solutions (GFRP), a well-established method for consolidation and reinforcement of the excavation face in underground construction, enhance soil stability and improve safety conditions. Our portfolio features a wide range of innovative solutions:

  • Profiles and elements in fibreglass of different section
  • The customizable anchoring systems P.E.R. Ground
  • Glass fibre reinforcement nets
  • Glass fibre reinforcing bars

Corrugated Fibreglass Hollow Sections

The corrugated fibreglass hollow sections, made from a polyester resin matrix reinforced with continuous unidirectional E-Glass type GFRP fibres, maintain the integrity of the fibres throughout their length. This uninterrupted fibreglass reinforcement significantly enhances tensile strength and pull-out resistance. The corrugated design also increases adhesion, and when combined with the high tensile capacity of the tube, ensures reliable stabilization of the excavation face.



P.E.R. Ground System

The P.E.R. Ground System, designed for challenging excavations, combines a fiberglass-reinforced element with an expandable sheath, filled with pressurized mortar. This system improves pull-out resistance, efficiently controls mortar usage and reduces perforations by up to 45%, enhancing safety and saving resources. P.E.R. Ground is customizable in various combinations, allowing multiple functions to be performed simultaneously (e.g., P.E.R. Ground Drain for both reinforcement and drainage).