FIBRE-REINFORCED CONCRETE SLABS

THE CHALLENGE

Polished concrete floors are a popular and fashionable option for commercial, retail, and even residential construction projects. When the design was finalized for the impressive Torre Glorieta tower project, a plan for polished concrete floors on all 18 office levels was included. With the help of value-added concrete and on-site mixing, the crack-free floors were poured without a hitch. The risk in polished concrete floors lies in the required absence of cracks and curled joints, a tall order for any job. However, for Constructora Cimet—the owners, designers, and managers of the Torre Glorieta project—this was not an issue.

THE SOLUTION

The Torre Glorieta’s pristine polished floors were accomplished in two ways. Firstly, no wire mesh was used. Instead, synthetic fibre was added to the cement powder to reduce the cracking that concrete suffers during the hardening process. The concrete crew used about three kilograms of fibre per square metre, pouring for about four hours at a time to cover half a slab. Macro synthetic fibre was used, which provides similar benefits to steel fibre, but without the potential for corrosion. Deciding on a volumetric mixer, the team chose ProAll Mixer for all the building’s concrete. Using a volumetric mixer enhanced the crack resistance capabilities of the fibre. Fibre is optimally used when uniformly distributed and randomly oriented within the concrete. This aspect was further enabled by the use of a volumetric mixer—adding the fibre as it was mixed meant even dispersal and exact amounts, as well as the ability to pour continuously.

ON-SITE MIXING

Another reason for such quality concrete on the project was the use of a ProAll Volumetric Mixer. Using a mobile mixer meant the concrete was mixed on site. Not only did the decision to use a volumetric mixer solve supply chain issues related to location and traffic, on-site production gave the concrete crew better quality control. “You can see that even when it is inspected up close and in detail the cracks are minimal compared to any other construction that does not have the opportunity of having the concrete manufactured right there at the site,” says Tapia.

POLISHED CONCRETE FLOORS

3kg

OF FIBER PER SQUARE METRE

4hrs

PER HALF SLAB

In our city, due to the complex transit, the builders have to bring the concrete in mixing trucks that take more than one and a half or two hours of driving before it can be poured, which makes the concrete lose some of its main properties. With the opportunity to have a concrete manufacturing plant close to the structure, we have the advantage of using concrete with better properties than other construction sites

Carlos Tapia, Structural Engineer for CTC Ingenieros Civiles