Preparation Of Wood Fiber Reinforced Gypsum-based Composites And Their Application In Interior Design

Gypsum in gypsum-based composites is an air-hardened cementitious material with high brittleness,poor water resistance and easy to fracture,which limits its use in the construction field.Therefore,this project prepares wood fiber-reinforced gypsum-based composites for the disadvantages of low toughness and poor water resistance of gypsum products,and studies the preparation process and toughening properties of the composites,aiming to provide theoretical basis for their application in the field of new building materials,and the results of the study are as follows:(1)The best process ratio of wood fiber reinforced gypsum-based composites is 10%wood fiber admixture,30-40 mesh wood fiber,and 0.7 water-paste ratio.The absolute dry flexural strength of the composites under this process is 25%higher than that of pure gypsum,the water absorption rate is reduced by 10%,and the softening coefficient is improved.(2)The longer the maintenance time of the specimen,the higher the strength of the composite;the results of the pore structure analysis show that the addition of wood fiber makes the pore size of the composite pore larger,but with the increase in the number of wood fiber mesh,the pore size of the pore drops back,and the fiber reinforcement effect of too high mesh is not good.The higher wood fiber addition leads to the increase of peak heat release rate(pkHRR)and total heat release(THR)of gypsum-based composites,and their flame retardant properties are weakened.(3)The water resistance of the gypsum-based composites with single cement addition was enhanced,but the mechanical strength decreased to some extent;the mechanical strength of the composites with single PVA addition increased,but the water resistance deteriorated;the flexural strength and compressive strength of the composites with cement and polyvinyl alcohol(PVA)synergistic enhancement increased by 40%and 63%,respectively,compared with the unmodified composites,and the 2-h water absorption rate and 24-h water absorption rate decreased by 10.17%and 11.17%,respectively,compared with the unmodified composites.The 2-h water absorption and 24-h water absorption decreased by 10.17%and 11.97%,respectively,and the softening coefficient increased by 0.4,indicating that the two materials synergistically compensated the defects of low strength of cement alone and poor water resistance of PVA alone.(4)PVA emulsion and gypsum,cement hydration reaction will affect each other.Fourier infrared spectroscopy(FT-IR)and scanning electron microscopy(SEM)results show that the addition of cement produced hydration products such as calcium vanadate and calcium silicate gel inside the composite;PVA cross-linked and polymerized in the gypsum-cement slurry to form a network structure,which wrapped the cement gypsum particles and changed the microscopic morphology of the hydration products;XRD results show that the addition of PVA had little effect on the internal XRD results showed that the addition of PVA had little effect on the composition of the material inside the composite.(5)The wood fiber-reinforced gypsum-based composites were applied in interior design,showing the characteristics of natural antique color,and their appearance was similar to that of pure gypsum board.Through secondary processing,the color and texture of other materials can be simulated,and the decorative effect is not inferior to other materials.It provides sustainable and green alternative solutions for ceilings,partitions and other applications,while broadening the prospects of gypsum-based composites in the field of building materials.