Admixtures: invisible but indispensable

What were the most difficult problems you came up against during construction of the piles and how did you overcome these problems?
Mapei’s collaboration in the project started with construction of the reinforced concrete columns supporting the bridge, which in this case feature an elliptical form and are made from concrete cast using climbing formwork. To guarantee consistency of the most significant properties and enable the piles to be constructed in a continuous cycle meant   guaranteeing their mechanical properties over a specified period of time, for which we used the latest, cutting-edge Mapei admixtures with the capacity to modify the hydration process and hardening rate of cementitious materials, so as to be sure they achieved the expected levels.

What part did Mapei play in the final surfaces of the piles?
A particularly important requirement of the client was that the exposed surfaces needed to have an excellent finish once the formwork had been removed, with no surface defects in the concrete, and that the colour had to be uniform. The requirement was achieved to the full, thanks not only to the correct design mix for the concrete, but also to MAPEFORM W60, a form-release agent in water dispersion for concrete.

Once the piles had been completed, it was time to cast the slab for the deck. What factors had an influence on the choice of products?
For this phase, too, various design factors had to be taken into consideration, such as the particularly high mechanical properties required, the rate of compensated-shrinkage, which had to be maintained within specified limits, and extended workability in hot weather, because the concrete for the slab was actually placed in June, 2020.

From the amount of products used we can get a sense of how challenging it must have been for Mapei to guarantee the right level of technical support. How did you organise your work?
Through incredible teamwork, and by being perfectly synchronised with the manufacturer of the concrete so that the most suitable materials were employed to achieve the properties required, with our mobile laboratories stationed in the mixing plants to check the concrete and make sure the values corresponded with the results we achieved in the lab and, lastly, by constantly monitoring the site throughout its entire duration.

It must have been a very important experience for you?
Concrete admixtures are invisible because, from the moment they are introduced into the concrete, they no longer exist physically. However, they are indispensable to achieve the performance properties prescribed in technical specifications and to construct infrastructures that remain durable over the years. To have played such an important part in the construction of this great work brought enormous satisfaction to every department and division of our company.