Durability of ettringite-based composite reinforced with polypropylene fibers under combined chemical and physical attack

High-performance fiber reinforced cementitious composites from ettringite-based binders require much under-standing of durability before its real-life applications in construction industry. A strain-hardening fiber re-inforced ettringite-based composite from the hydration between ladle slag and gypsum with polypropylene (PP) fibers was the object in this study. To investigate the durability of the developed composite under aggressive conditions in cold regions (e.g., the Northern Europe), the material was subjected to a combined sodium sulfate-chloride solution along with freeze-thaw cycling process, which represented the marine environment of cold regions. The experimental study reports the vital role of PP fibers in control crack propagation and, hence, greatly enhanced the durability of the composite. In addition, the developed composite attained good mechanical performance with deflection-hardening behavior and multiple crack even after aging processes. Materials, aged in water, was mainly destructed by volume expansion from water uptake in structural pores, while those, cured in Na2SO4-NaCl solution, was mainly spoiled by volume increase from both physical and chemical attacks.