Civil sector - Innovative technologies - Structural consolidation
Antique buildings often need much more complicated work compared to a simple renovation. These structures require structural consolidation work due to the ageing of the materials composing the framework. Deldossi studies the basic structure of the building in detail to be able to intervene in the best way on elements that have deteriorated over time. In this way it allows the structure to resist over time and to avoid unpleasant consequences, such as collapse, which time and atmospheric agents can bring about. We offer solutions for any type of structure: consolidation of walls and mending of damaged walls, regardless of the materials with which they were built, vaults in masonry, foundations, vaulted ceilings and wooden structures.
Vault consolidation
Vault consolidation using filled brick or stone, without frescoes or other decorative treatments consists in:
  • shoring of vaults on the floor below
  • cleaning of extradosal surfaces until the structural elements are bare
  • sealing and mending of damage, in both the extra and intradosal parts, with flaked stone and suitable complying mortar, if possible, with the characteristics of the original to restore the structural and aesthetic continuity
  • perforations measuring 16 mm in diameter, at least 6 per m2 reinforcement of them with 8 mm rods for improved adherence, blocked into place with suitable mortar or resins
  • provision and placement of electrowelded netting with a minimum diameter of 5 mm, with a 20x20 cm mesh
  • implementation on the extradosal surface of a concrete cladding with a thickness of about 4 to 6 cm
  • formation pockets in the load-bearing walls for placement of reinforcing beams and casting anchored to the concrete cladding
  • demolition of part of the vaults and walls to form passageways on the ground floor, including insertion of iron architraves to support the walls and formation of thin flooring between the vaults and the walls
  • cut of the walls all over the perimeter of the vaults for placement of the flooring
  • floor sealing formation with a thickness of 12 cm on the extradosal of the reinforcement beams and on the load-bearing beams
Stone wall consolidation
Rubble masonry consolidation.
The internal gaps and unevenness of the brick, stone or mixed walls can be filled by way of gravity casting with resistant sulphate binding cement with controlled pouring, with a single component based on modified cements and fluidifying and expansive additives. The end result of the work is that the wall is brought together by filling the internal gaps and unevenness with a suitable product compatible with the chemical and physical characteristics of the original structure. Therefore any kind of wall surface covering that was dilapidated, detached or simply had unsuitable mechanical characteristics was removed. All superficial unevenness (such as joints between elements, cracks, fissures) were stuccoed to avoid bulging of the fresh product. On the wall vestment perforations were made of 16-24 mm in diameter at a suitable depth and with wooden planks inclined slightly downward, at a distance of 80-120 cm apart. The holes form a regular vertical and horizontal grid on the surface of the wall. Injection tubes were set inside the holes with quick setting mortar. Water was injected into the previously injection-closed circuit to saturate the porosity of the material and to remove all possible debris from the inside 24 hours before the injection of the clogging mortar. The pattern of the grid and the distance between the holes was based on the depth of the wall, its nature, and the structural demands. The injection is done from injection tubes placed lower, until the fluid grout bulges from the adjacent or superior tubes. Then the injection tubes are closed, from which a fluid material seeps and then the upper ones are injected all the way to the extradosal of the wall. 2-3 days after the first injection a second grid of holes is made at the centre of the first (intermediate and offset to the previous ones to perform more filling of the wall with the same procedure as before).
Reinforcement of the wooden floors
The floors consist of a wooden framing, to which the plastered and frescoed wattle of the lower floor is fixed, while there is a double layer of plank floor, crossed perpendicularly one on the other to the extradosal on which the slab and floor stand. After demolishing the boardings, the existing floors, the cement slabs and the technological systems, the upper plank floor layer is removed, the underlying one is cleaned, and the fissures in correspondence of the joists of the framing are broadened; holes are then made along the plank floor cracks in correspondence of the joists, at the distance that the plan indicates. Iron connectors are set through epoxy resins and, after the resins dried, an electrowelded net of D=8 20x20 mesh, is fixed to them; lastly the reinforcing slab with 1600 LECA for an average thickness of 12-15 cm is cast.
Damaged element mending
The work consists in fixing the walls damaged by the shifting of the land, time and atmospheric agents. To do this, all old and ruined parts are eliminated and replaced by new materials in order to give the structure solidity.
During the work the structure is held up by support poles so that to avoid further collapse and damages.