Spalling behaviour of CFRP-reinforced concrete and effectiveness of fire protection measures

In the building construction sector, there is a growing need for lightweight systems with reduced environmental impact. A new construction method involving the combined use of concrete with a high compressive strength and carbon textile reinforcement or more specific Carbon Fibre Reinforced Polymers (CFRP) with high tensile strength has been developed. Because CFRP is corrosion-resistant, concrete cover can be minimized, resulting in more material-efficient and slender cross-sections.
However, concrete with high compressive strength is susceptible to explosive spalling under fire exposure when no mitigation measures are used. Spalling reduces the load-bearing cross-section and exposes the reinforcement directly to fire, potentially causing sudden structural failure. This study evaluates the spalling behaviour of high-strength, fine-grained concrete typically used with textile reinforcement, including the influence of the textile reinforcement. The effectiveness of intumescent coatings and fire protection boards in preventing spalling in CFRP-reinforced concrete is also examined.
Unprotected specimens consistently exhibited explosive spalling. ... mehrWhen protection measures such as intumescent coatings or fire protection boards were applied, specimens without textile reinforcement or with the tested acrylate-based CFRP variant showed no explosive spalling. However, even with these protective measures, specimens reinforced with the tested epoxy-based CFRP variant still experienced spalling.