The mortars and grouts existing in the joints of the foundations of wind turbines, are placed on site, in very diverse landscapes (deserts, oceans, etc.) and extreme environmental conditions of temperature, humidity, salt spray, etc. These joints work under fatigue strength as a critical element in the pole structure.
The building project needs to avoid risks in this joints and this is why the Engineering, Certification and Insurance companies need to have material properties and requirements to be tested in the worst environmental scenarios.
The manufacturer of the grout powder usually performs the identification tests. Some of them are double-checked by the reference laboratory. But the core of the tests are carried out on the fresh grout and on the hardened grout.
If a qualification of the grout is required, at least two batches will be tested.
The key point for fresh grout are the high number of tests in different conditions from 0 up to 35 ºC with all the raw materials and the machines in the designed temperature. Also Setting Time, the Air Content, Sedimentation and Bulk Density are tested.
The main test is the Fatigue Strength, with dynamic tests, with a global amount of 44 million cycles. Other static tests are needed like the Compressive Strength, Tensile Strength, Flexural, Modulus of Elasticity, Poisson’s Ratio, Density, Chloride Ion content, Pull-out resistance, Shrinkage, mortar Expansion, Autogenous Shrinkage, Freeze-Thaw cycling, etc.