Wind is a clean source of renewable energy, with minimal operational costs once a turbine is erected. Technological advances, and production process improvements, are reducing the construction costs for wind farms. Hence the increasing number of farms around the globe.
By the nature of their operation, wind farms must be positioned in extremely exposed regions, where unimpeded, consistent, robust breezes can be guaranteed. On-shore farms are typically constructed with a very heavy concrete base, which must have the strength to withstand the constant force, and leverage, on the turbine tower.
Not your average concrete construction.
Strong concrete?
The massive bases typically require in excess of 500 m3 of concrete each. Mix design is obviously crucial, with high GP cement content and other additives to achieve minimum permeability.
Critically, curing will play a vital role in the long-term strength of the concrete.
Specific curing challenges
The exposed conditions of the construction mean that ambient winds can hasten surface evaporation, with a negative impact on hydration quality. Excess evaporation means an increase in shrinkage cracking and bleedwater porosity, setting the scene for premature deterioration of the concrete itself.
Further, these same conditions may bring lower ambient temperatures. Where ambient temperatures are less than 10°C, it takes longer for the concrete to achieve its anticipated strength. The temperature differential between core and surface – given the sheer volume of concrete – can contribute to uneven curing resulting in internal weakness.
Extra protection is needed!
We’d like to introduce a couple of key options, for protecting the concrete and enhancing the curing process.
1. Enhance curing with hydrogel treatment
AQURON concrete hydrogel treatment is an excellent curing enhancement, equal or superior to 14 days’ water curing. And there are permanent benefits: the concrete porosity is sealed, and the slab hardened to a depth of 150mm, giving long-term durability.
2. Protect the slab with thermal curing blankets
CONQOR TCBs have proved popular for wind farm projects in cooler regions, protecting the slab against surface temperature loss and the resulting thermal differential. This in turn preserves the intended strength of the concrete.
Not only for wind farms!
Keep in mind that these are valid and practical solutions for a range of civil construction projects in exposed locations.
The MARKHAM team has accumulated years of experience in a very wide array of project types, and we’d love to talk to you about your project! Why not get in touch today?
Banner – Photo by Harry Cunningham @harry.digital from Pexels
Wind farm at dusk – Photo by Irina Iriser from Pexels
