Know-how

Stone

Consolidation of masonry with composite pins

The composite materials used are glass and carbon fibre rebars

They provide high resistance, insensitivity to corrosion, and low thermal expansion: an ideal reinforcement for masonry and ashlar structures.

They can take up shea stresses such as for balcony corbels, tensile stresses over great lengths (tie rod) where they serve as steel reinforcement in concrete or as replacement for metal systems in reinforced stone that is splintering subsequent to the metal's corrosion.

Placed in core drilling holes (lengths of up to 30 metres are possible with rebar rods butted together using bonded carbon sleeves or by covering the elements) or in grooves, these composite rebars are sealed using RENOFORS PIERRE (stone) or RENOFORS PIERRE THIXO resins (thixotropic resin used to assemble glass or carbon fibre tie rods in stone).

Reinforcement of vault arches

The high performances of composite rebars and their implementation allows to consolidate and reinforce existing structures, while preserving their structural and architectural layouts.

The RENOFORS ARCATURE process is used to pin together the elements of an arch.

The upper masonry is connected by placing composite rods (made of glass or carbon fibre) according to the intensity of the stresses. They are sealed using RENFORS PIERRE resin in core drilled recesses. The mechanical characteristics of the rebars and the implementation methods allow to consolidate and contain stone arches without altering their architecture or their original structural characteristics.

Tying of walls using composite tie rods embedded in the masonry

The usual methods used to tie walls of buildings lead to the implementation of metal tie rods whose extremities are secured with metal anchors that more often than not are visible. Beyond the aesthetic appearance, this system concentrates the stresses at the extremities in line with the anchors and causes pressure bulbs. The nature of the tie rods exposes them to the effects of metal corrosion and to all induced stresses.

The wall tying system that RENOFORS has developed implements composite fibre tie rods which are chemically inert. Sealed over their entire length using RENOFORS PIERRE resin, they harness the entire masonry in a linear and uniform manner. They ensure high structural performances but do not add any stresses to the structures. The core drilling performed using air or water-cooled diamond tools do not cause any percussion or vibration in the masonry already subject to structural disorders.

If necessary, reinforcements can be post-stressed in order to further increase the performances of the strengthening system. The wall ties are invisible and do not alter the architecture of the façades.

Exposed tie rods

Some tie rods in certain buildings are exposed (e.g. transverse tie rods in naves or aisles). Nevertheless, the anchoring on the façade can remain invisible. Anchors are replaced with the rebars' sealing within the walls or completed according to the situation with additional rebars (also invisible) used to support masonry bulbs.
Renofors implements all kinds of tie rods: metal (stainless steel, Kevlar, titanium single-strand, and composite).

Post-stressing of composite rebars

In some cases, in order to reduce the number of tie rods and/or make them active (rebalancing of loads, etc.)
Renofors post-stresses the rebars using a hydraulic jack or a torque wrench depending on the stresses to be obtained.

Internal shoring and rebalancing of loads

The replacement of stone elements requires careful cleaning, which implies cumbersome securing operations with sizeable shoring.

In some cases, according to the nature and layout of the facilities, an internal shoring system can be implemented through a variation on the RENOFORS PIERRE process (stone process) by inserting composite fibre rebars in the masonry and sealing them with resin.

Similarly, this principle can be applied to rebalance loads by installing rebars sealed in core drilled holes, in order to take on unwanted thrusts or stresses without altering the architecture of the buildings.

Moving of assembled structures

The pinning and tying methods mentioned in the previous sections can be used to consolidate a set of structures, e.g. porches, statues, altars, pediments, etc. while preserving the original structural characteristics.

Moving these structures thus is greatly simplified, considering modern and fast cranage means.

These methods allow to limit – if not eliminate – dismantling operations that can be detrimental to the structure.

Pinning of statues and facings

The various possible applications and variations of Renofors processes can be used to consolidate structures as varied as elements of architecture and of monumental sculptures.
The RENOFORS PIERRE (stone) and RENOFORS ASSISES (course) techniques can be used to consolidate, reinforce, and stabilize delicate and complex structures

Strengthening of ramparts and stabilization of ruins

The RENOFORS PIERRE process (stone process) is often used to stabilize ruins, strengthen ramparts, spike rocks, or make the masonry more homogenous.

The RENOFORS PIERRE process is used to make old walls more homogenous by associating the interior and exterior facings, to anchor masonry or overhanging architectural elements. This technique can be used in the substructure to increase the cohesion of the foundation masonry. An extended load repair bulb is thus created, which limits ground-crushing effects.