Posted by José María Vaquero - 25 March, 2020
Construction projects at ports often involve highly specific requirements: The salt-laden air attacks the concrete, which, nevertheless, has to be able to withstand sustained extreme mechanical impact. Combining polymer fibers from the MasterFiber range for reinforcement and an innovative MasterEase plasticizer for easier and more efficient application, the experts from Master Builders Solutions found the ideal concrete mix design for the floor slabs of a new freight terminal at the Port of Barcelona.
Located about three kilometers to the south of the historic center of the Catalan metropolis on the Mediterranean Sea, the Port of Barcelona comprises more than 30 terminals. While a small number of them is reserved for ferries and cruise liners, the vast majority is dedicated to the large-scale movement of commercial goods, such as refrigerated and bulk cargo, liquids, metals, tropical fruits, and coffee. Set to increase the capacity of this part of the port, the design for the new cargo terminal includes an overall storage area of 81,000 square meters. The project also includes 30,000 square meters of foot paths and another 30,000 square meters of pavement.
Salt and weight impact up requirements
Next to high requirements in terms of mechanical resistance – mainly due to the heavy vehicles and machinery used for loading and unloading, for goods delivery and collection – a very particular kind of chemical impact had to be taken into account as well: the increased salinity of the air in the maritime climate; while this factor alone would accelerate the corrosion of the concrete as well as that of the steel reinforcement typically incorporated in the material, the intended use for bulk salt storage compounded the challenge. Thus, the crucial properties for the concrete used in the project included a high resistance to chloride impact.
Corrosion-free reinforcement with MasterFiber
The solution: fibers of the MasterFiber range from Master Builders Solutions. The corrugated polymer fibers are designed to partially or completely replace steel reinforcement, and they do not corrode – not even in the demanding environment of the new cargo terminal at the Port of Barcelona. Moreover, they provide high-strength properties even in cases where micro-fissures are present in the concrete. “The MasterFiber product range allows us to manufacture a high-performance concrete”, confirms Jordi Altet, Qualtity and R&D Manager at Promsa, the concrete producer commissioned for the project. “The fact that the fiber is corrugated enhances its bond with the concrete matrix and provides higher flexotraction resistance compared with other fibers.” And there also is a cost benefit over conventional steel reinforcement that, depending on the specifics of the project, can be as high as 40%.
MasterEase for efficient placement
The addition of the innovative MasterEase plasticizer greatly facilitated the placement of the fiber-reinforced concrete: “Construction requirements were complicated”, reports Ferran Casaus, Chief Sales Manager Admixtures Iberia at Master Builders Solutions. “The main benefit provided by MasterEase is the reduction of concrete viscosity, the ‘stickiness’ of the material, by up to 30%. Additional benefits include an optimization of the rheology of the concrete, the retention of consistency across extended periods, and the reduction of the water content in the concrete, which serves to enhance strength properties.” MasterEase is also highly suitable for use in concretes that incorporate demanding aggregates or a high ratio of supplementary cementitious materials – these, too, will be significantly easier to mix, pump, place and finish. And what is more: equipment such as mixers, pumps and piping will also benefit from a concrete optimized with MasterEase, which serves to reduce machine wear and tear and significantly extends equipment service life.
Benefits across all project stages
“The use of structurally supporting polymer fibers yielded benefits across all stages of the project”, says Carles Cots, Fiber Business Manager Europe at Master Builders Solutions, and adds that, compared with conventional reinforcement, they accounted for savings in labor of about 50%. In addition, the concrete slab could be produced without the use of pumps. Over time, reduced maintenance requirements will make for additional savings as, unlike steel reinforcement, polymer fibers are completely corrosion-free.