Antana would like to share the construction solutions we have implemented to reinforce and consolidate the concrete pillars in the refurbishment of a house in Madrid.
The affected structure consists of 6 pillars of 11cm x 11cm section which, as can be seen in the image, showed significant damage. The longitudinal reinforcement of the pillar was made of smooth steel rods which, under the loads supported, had "detached" from the concrete. This type of reinforcement ceased to be used several decades ago, and was replaced by corrugated rods with frames to improve the adhesion between steel and concrete.
The first step was to clean up the pillar by removing the disintegrated pieces of concrete. Also, as the reinforcement showed signs of rust, it was necessary to passivate it and apply a protective film of synthetic resin and silica fume (Sika® MonoTop®-910 S). It was applied directly by brush, once it had been mixed with water, to improve its adhesion with the repair mortar that would be applied later.
In this case, a product enhanced with synthetic resin and silica fume (Sika® MonoTop®-910 S) was chosen.
It was applied directly with a brush, after kneading with water.
Once the reinforcement had been repaired, the column section was recomposed by applying a non-shrink mortar (Sika® MonoTop®-618). For this purpose, two opposite sides of the column were formed and the mortar was added in successive layers (up to 80 mm thick, according to the manufacturer's specifications).
Once the original section had been reconstructed, it was clad with 10 mm thick rolled steel planks, already U-shaped from the workshop, supported on 16 mm thick steel plates with a surface area of 60 cm x 60 cm on a base levelled with mortar.
For the placement of the pillar casings, clamping jacks were used to reduce vibrations to the pillars.
Subsequently, 400 mm x 400 mm x 12 mm plates were placed at the head of the new columns in order to collect the loads and avoid punching of the new casing into the existing slab.