Concrete strength evolution in WTG foundations
Onshore WTG foundations are massive cast-in-place concrete structures and essential components in the Balance of Plant (BoP) of wind projects. Optimizing the construction process of these foundations can lead to significant gains in the overall project efficiency.
How's concrete strength measured
Concrete's compressive strength doesn't develop instantaneously. Instead, it increases over time as a result of the chemical process known as cement hydration. When water is added to cement, it triggers a reaction that forms new compounds, ultimately creating a rigid, stone-like structure. If you want to know more about cement hydration, check out this post.
The most significant gains in compressive strength occur within the first few days after the concrete is cast. During this period, the concrete is rapidly hardening. As time progresses, the rate of strength gain slows, but the concrete continues to become stronger.
In the construction industry, concrete is typically designed to achieve a specific compressive strength at 28 days. This 28-day strength is a standard measure used for the design and assessment of concrete structures. It serves as a key reference point for engineers to ensure that the concrete will be able to support the intended loads over the lifespan of the structure.
At 28 days, the majority of the concrete's strength has been realized, providing a reliable indication of its final performance characteristics.
Assessing the strength at early ages
While the 28-day strength is an important benchmark, there are significant advantages to assessing concrete compressive strength at earlier ages.
By the evaluating the strength before the 28-day mark, construction teams can make more informed decisions that lead to significant optimizations in the construction process.
Modern technology is instrumental in enabling accurate early-age strength assessment. Advanced sensors, data analytics, and simulation tools can predict the strength evolution over time. These tools provide real-time data that allow construction teams to make dynamic decisions based on the actual performance of the material.
Simulation of the concrete strength evolution in a WTG foundation
The plot below illustrates the rapid increase in strength during the first two to three days in a WTG foundation for a wind project located in a hot weather region. This simulation allows us to identify the strength development at critical regions of the foundation and assess whether subsequent construction operations can be performed safely without compromising the integrity of the structure.
With this information in hand, project managers can confidently adjust construction schedules, optimize resource deployment, and ensure that every aspect of the project is progressing in sync with the concrete's actual development, rather than relying solely on traditional timelines. This approach allows for schedule optimizations of operations such as backfilling or anchor cage bolts preloading.
If you are looking to optimize your construction planning by leveraging advanced numerical simulations to predict the strength evolution in your wind turbine foundations, don't hesitate and get in touch 📧.