An Investigation into the Effect of Pre-treated Milkweed Fibers on Hydration of Portland Cement: Fid-Bau Portal

An Investigation into the Effect of Pre-treated Milkweed Fibers on Hydration of Portland Cement

Sabziparvar, Amirmohammad / Taleponga, Donato / Foruzanmehr, M. Reza

Pre-treated milkweed fibers have been shown to have excellent hygroscopic properties, making them suitable for superabsorbent applications. These hollow fibers can be particularly used as a sustainable substitute for non-renewable superabsorbent polymers and act as an internal curing agent in cement paste mixes with low water-to-cement ratios. This study investigates the effect of pre-treated milkweed fibers on the hydration of Portland cement paste for internal curing agent application. Milkweed fibers were pre-treated by hydrothermal treatment and hybrid treatment, which combine the hydrothermal treatment and alkaline treatment. The impact of different pre-treated milkweed fibers on the hydration reaction of cement paste was investigated using thermogravimetry analysis (TGA/DTG), X-ray powder diffraction (XRD), and differential scanning calorimetry (DSC). It was observed that different pre-treatment methods resulted in MW fibres with different chemical compositions. While hydrothermal treatment removed waxes and pectin from MW fibres, hybrid treatment removed lignin and hemicellulose. According to the result of the study, the incorporation of hybrid treated MW fibers to cement paste samples improved cement hydration by forming more chemical bond water, which promotes the hydration of C₃S and C₂S and increases the production of CH and crystallized calcite. Contrarily, non-treated MW fibres and hydrothermally treated MW fibres performed less effectively as an internal curing agent than the hybrid treated fibre, primarily due to presence of lignin and hemicellulose and their retarding effect on the cement hydration reaction.