80 m2 of pavement lifted with precision of 1 mm

SUMMARY

The “Taverne Tennis School”, active since 2006, has 4 covered outdoor courts and 3 courts within the large indoor room. Over time, the subfloor of the pavement of some areas of the indoor courts had lowered, causing depressions that were incompatible with the proper use of the fields. According to the client, this was done because of the presence of fill material and water infiltration below the slab.

OBJECTIVES

The goal was to compact the subfloor of about a total of 80 m2 of pavement, spread over 3 areas, restoring the original flatness. The intervention should not cause undesired liftings of the floor, also avoiding substantial interference with the use of the structure.

TECHNOLOGY APPLIED

By applying the GeoResin® Floor Lifting technology, it was possible to fill in the voids by injecting the GeoResin® swelling Geopolymers, designed specifically for this type of work.The completion time of the polymerization reaction of the Geopolymers is very fast. Such feature allows the material to remain confined in the surrounding area closest to the injection point, without dispersing too far. This allows precise lifting with millimetric tolerances. The bearing surface of the flooring was detected at a depth of 0.10 m from the floor surface. The drillings with a diameter of less than 3 cm, driven through the floor and extended to a maximum length of 0.80 m over its thickness, were spaced at regular distances. This way, it was possible to reach all the so-called “significant” volume with precision. At the end of the drillings, injection tubes were placed, introducing them into the holes. The injections were performed on two different levels of depth, starting with the most superficial one. The injections were done at levels of 0.20 m and 0.80 m from the bearing surface of the floor.

OUTCOME

By expanding, the Geopolymers reinforced the subfloor in the area surrounding the point of injection, restoring the contact between the subfloor and the flooring. Continuing with the injection, it was possible to produce a precision lifting of the sunken areas. The vertical lifting of the floor is an indicator of the efficacy of the treatment. The swelling process of the Geopolymers, in fact, causes densification of the soil in different directions from the vertical. During the work, the vertical displacements of the pavement were monitored with the use of laser instruments of millimetric precision. The average lifting was 50mm. The operation, which involved about 80 m2 of pavement, happened in two working days.