Freeze-Thaw Endurance of Strain-Hardening Cementitious Composites with Low Clinker Content

This paper delves into the influence of freeze-thaw (FT) cycles on the mechanical and cracking behavior of strain-hardening cementitious composites (SHCC). These composites were made using a low carbon cementitious matrix – limestone calcined clay cement (LC3) – and reinforced with 2 wt.% ultra-high molecular weight polyethylene (PE) fibers. Performance evaluation was conducted through uniaxial tension tests at a quasi-static deformation rate. Some specimens were preloaded to 1% strain before FT exposure, while the others were investigated without any damage (virgin). All the specimens were then subjected to standard FT cycles as per RILEM recommendations (TC 117-FDC) and exposed to both de-icing salt solution and distilled water for a total of 180 cycles. Following this exposure, further uniaxial tensile tests until ultimate failure were carried out. Analysis of mechanical properties unveiled a marginal deterioration in tensile strength post-FT cycles compared to reference samples. However, all composites sustained a reasonable strain capacity of a minimum of 2.5%, with an average crack width controlled at around 100 µm. From a physical degradation standpoint, evident scaling manifested only when specimens encountered FT cycles in de-icing salt solution. In general, SHCC made of the LC3 matrix showed exceptional resilience to such challenging environments, maintaining a level of performance deemed satisfactory.