Experimental study on the long-term performance of sisal fiber reinforced high-performance concrete subjected to drying-wetting cycles

Plant fibers have been gradually used in cement concrete. However, the long-term performance of high-performance concrete (HPC) reinforced with plant fibers has yet to be studied. This paper investigated the degradation of sisal fiber in HPC subjected to 9 months of drying-wetting cycles. The mechanical properties of HPC specimens were tested, and the degradation of sisal fibers in the HPC matrix was characterized by thermogravimetric analysis, X-ray diffractometer, X-ray photoelectron spectroscopy, and scanning electron microscope. After drying-wetting cycles for 9 months, the mechanical properties of the HPC specimens showed little change (within 10 %); the lignin content of sisal fiber was significantly reduced (the C1/C2 value was decreased by 68.9 %), and a portion of the cellulose was also subjected to alkaline hydrolysis, but there was no significant mineralization phenomenon. Therefore, sisal fiber reinforced HPC has good long-term performance under drying-wetting cycle conditions, but its durability under the coupling of multiple deterioration factors still needs further exploration. • The long-term performance of sisal fiber reinforced UHPC was investigated. • The mechanical properties of UHPC were not affected by drying-wetting cycles. • The sisal fibers inside the UHPC did not exhibit obvious degradation characteristics.