The enlargement of the Punta Sollana breakwater dock in Bilbao comprised a research, development and innovation project designed to attain a high-performance concrete created through recycling industrial by-products generated in steel manufacturing.
The expansion of the port of Bilbao has been completed using new, more efficient, environmentally-friendly materials. Sacyr was responsible for the work and developed an R&D&i project to attain a high-performance concrete by reducing its volume and increasing safety aspects.
Whereas in the enlargement of the Panama Canal unique and special concrete mixes were used in order for the project to meet the durability requirements, Sacyr’s ongoing research work has achieved a new composition, this time intended for the Basque port. The project has used industrial by-products generated by the ordinary steel manufacturing process in the electric arc furnaces of various steelworks in Vizcaya.
The 330-metre-long Punta Solana breakwater dock, measuring 60 metres in width, was built using concrete with a density of 2.65 tonne/m3. To achieve this strength, in this area of Bilbao’s industrial port Sacyr used a steel aggregate from recycled black slag material, a mix of metal oxides with a greater density than natural aggregates.
Innovation with special advantages
However, what does all this achieve? With these mixtures, Sacyr has managed to create a much slenderer crown wall for the breakwater with an elevation of the same height as that for the project. In addition, the concrete mixes provide high levels of resistance to compression and penetration of low-pressure water, and resistance to frost, thawing, fire and sea water.
They also more than meet the required levels of elasticity, density, porosity and performance with regard to carbonation. This concrete has made it possible to use blocks, which, being the same weight as the project blocks, perform much better within the breakwater’s protective layer, as the sizing is carried out in proportion to the cubic density, not to the weight.
Approximately 18,000 eight-tonne concrete blocks and 3,000 concrete blocks weighing 75 tonnes were used in the construction project. In addition, one million cubic metres were used of fill material, divided into large boulder rip rap up to 500 kg (20%) and quarry run (80%).