Research On The Performance Of Basalt Fiber Reinforced Phosphogypsum-based Composite Cementitious Material

Phosphogypsum(PG)is a kind of industrial solid waste with high yield and low utilization rate.Phosphogypsum based composite cementite material(PGCs)is an effective way to consume phosphogypsum,but it has low bending strength and poor water resistance,so it is often modified by fiber.However,in the current study of fiber-reinforced PGCs,there are some key problems,such as ignoring fiber diameter,using materials and research performance limitations,and using unreasonable research methods,which need to be further explored.Therefore,in this study,green high-performance basalt fibers(BFs)with different diameters,lengths and dosages were mixed into a new type of phosphogypsum matrix composite to prepare the same batch of basalt fiber reinforced phosphogypsum matrix composite(BFRPGCs),and the following studies were carried out:(1)Based on single factor experiment,to explore the basalt fiber diameter,length and content of PGCs shrinkage properties,water absorption,porosity and other physical properties and the compressive strength and the influence of mechanical properties such as flexural strength,toughness,and combining with different sample of X ray diffraction(XRD)and scanning electron microscope(SEM),gives the mixture phase composition and the natural gas hydrates,To analyze the mechanism of action of fiber.(2)Based on the two-factor three-factorial response surface(RSM)test,the influence of the length and dosage of basalt fiber on PGCs was investigated,and the influence of the diameter,length and dosage of basalt fiber on PGCs was investigated by box-Behnken RSM test.The regression models of two RSM test analysis methods on flexural strength,compressive strength,porosity and water absorption were established to verify the feasibility of response surface analysis method and analyze the significant influence of basalt fiber parameters on PGCs,so as to predict the performance of BFRPGCs and realize its multi-objective optimization.(3)The influence of the diameter,length and dosage of basalt fiber on the water resistance,dry-wet cycle durability and freeze-thaw cycle durability of PGCs was investigated,the flexural and compressive strength and quality of the sample were recorded,the softening coefficient,strength coefficient and dissolution rate were calculated,and the damage condition of the sample surface was recorded.It is verified that basalt fiber in a certain parameter range can improve the water resistance and durability of PGCs.