The Necessity Of Alkali Resistant Glass Fiber Mesh For Crack Control Around Wind Turbine Foundation Rings

During continuous operation, wind turbines transmit alternating loads from wind forces and mechanical vibrations to the foundation concrete through the steel foundation ring. The pronounced stiffness mismatch between the ring and the surrounding concrete makes the adjacent region the most critical stress concentration zone, where micro-cracks initiate once the local tensile stress exceeds the concrete's ultimate strength. To effectively control cracking at the source, embedding Alkali Resistant Glass Fiber Mesh in the concrete cover around the foundation ring serves as a key technical measure-its flexible reinforcement action distributes tensile stresses and restrains the opening and propagation of micro-cracks, significantly enhancing the surface crack resistance of this vulnerable area.

Operational data indicate that within 3 to 5 years of service, concrete around the foundation ring frequently shows loosening, cracking, and even grout exudation. Fatigue-induced shear failure at the steel–concrete interface leads to debonding, and the lower flange repeatedly abrades the concrete, forming voids. Cracks not only reduce structural rigidity but also provide pathways for corrosive agents such as rainwater and chlorides, accelerating rebar corrosion and concrete deterioration. According to the Chinese code Design Specification for Wind Turbine Foundation of Onshore Wind Farm Projects (NB/T 10311-2019), the maximum allowable crack width under normal service conditions is 0.2 mm, underscoring the critical role of crack-control design. The installation is straightforward-placing the mesh in the stress-concentration zone prior to concrete placement-and adds no complicated procedures while delivering substantial durability benefits.

In conclusion, for wind turbine foundations subjected to the coupled effects of alternating loads and harsh environmental conditions, alkali resistant glass fiber mesh is by no means a redundant addition; it is a necessary engineering practice to ensure safe operation throughout the asset's service life and to minimize long-term maintenance expenditures.