Effect of alkali treatment on the mechanical properties and water resistance of bamboo scraps/magnesium oxychloride composites

Alkali treatment of bamboo scraps was adopted to improve the interface compatibility between the organic-phase bamboo scraps of the composite material and the inorganic-phase magnesium oxychloride. Scanning electron microscopy, Fourier-transform infrared spectroscopy, X-ray photoelectron spectroscopy, X-ray diffraction, and other techniques were used to characterize bamboo scraps before and after alkali treatment. The bamboo scraps treated with alkali exhibited improved bonding properties to cementitious materials. The mechanical properties and water resistance of the composite material were evaluated. The results indicated that the mechanical strength first increased and then decreased with an increase in alkali concentration. After treatment with 3wt% NaOH solution, the composite exhibited the highest compressive strength and bending strength. The softening coefficient also reached 0.57. Alkali treatment resulted in improved bonding of bamboo scraps with magnesium oxychloride cementitious material, as confirmed by mechanical property and water resistance tests, and SEM image analysis.