The water resistance and mechanism of FeSO4 enhancing bamboo scraps/ magnesium oxychloride cement composite

Ferrous sulfate (FeSO4) is used to enhance the water resistance of magnesium oxychloride cement (MOC) effectively in this paper. A FeSO4 reinforced bamboo scrap/magnesium oxychloride cement (F-BS/MOC) was prepared using ordinary agricultural and forestry processing waste bamboo scraps as toughening materials and FeSO4 as the water-resistant agent to improve MOC strength after soaking in water. The addition of 2% FeSO4 made the softening factor reach 0.82, and decreased the water absorption rate to 9.6%. To explore the waterresistance mechanism of FeSO4 reinforced composite, XRD, SEM, and XPS were used for analysis. The XRD results showed that FeSO4 did not introduce new crystals, but the crystal retention rate of the modified composite was significantly improved. The SEM image showed that the number of pores and pore size in the modified composite were reduced, and 518 crystals in a gel-state were formed. The fair characterization of XPS confirmed the existence of Fe-O(OH) and improvement of the bond energies of Mg-Cl and Mg(OH)2, forming a Fe-O(OH)phase 5 complex. The construction of the complex system showed the existence of Fe-O(OH) adsorption of 518 crystals; and FeSO4 enhanced the water resistance of the composite was thus embodied.