Numerical Simulation Research On Fracture Property Of Basalt Fiber Reinforced Reactive Powder Concrete

Normal concrete has some disadvantages such as large self-weight,low tensile strength,high brittleness and low toughness etc..Basalt fiber reinforced reactive powder concrete,as a new type of construction material,has a lot of outstanding performances.For example:high strength,good flexibility,good wear-resisting and impact resistance,it also shows good property in corrosion resistance.However,the study on basalt fiber reinforced reactive powder concrete is still in the initial stage,and most of the studies are on the aspect of basic mechanical behavior,only few are on the aspect of fracture property,especially,the numerical simulation study on the fracture property is basically in the blank stage. Therefore, the numerical simulation study on the fracture property of basalt fiber reinforced reactive powder concrete was performed in this thesis,here are the main study contents.In this thesis,the smeared cracking model was used in the numerical simulation. Cube compressive strength test,prism axial compression test ,cylinder splitting tensile test and three-point bending beam fracture test were done to get the relative parameters.Specimens including five different basalt fiber volume contents(0%,0.5%,1%,1.5%,2%) were tested to measure the influence of basalt fiber on the mechanical properties of reactive powder concrete.Based on the test results and related theories,the uniaxial compressive stress-strain curve,uniaxial tensile softening stress-strain curve and fracture energy applied to the fracture numerical simulation of basalt fiber reinforced reactive powder concrete were proposed.The parameters obtained from the tests were used to develop the smeared cracking model by using the finite element analysis software ABAQUS.The analysis of basalt fiber reinforced reactive powder concrete fracture failure process and the law of crack development were given by doing the numerical simulation of three-point bending beam with different basalt fiber volume contents,also the simulation curve of load-displacement(P-δ) and load-crack mouth opening displacement(P-CMOD)on the loading point were obtained.Compared with the test results,the relative difference of peak load on loading point is about 5%,the relative difference of maximum displacement on loading point is about 10%,and the relative difference of the maximum crack mouth opening displacement is about 8%.The numerical simulation results match well with the test results,that means the smeared cracking model developed before can reflect the complete fracture process of basalt fiber reinforced reactive powder concrete well.Based on the numerical model parameters,the ABAQUS finite element software was used to analysis the three-point bending beam with different seam height ratio,height and span-depth ratio,all of the basalt fiber reinforced reactive powder concrete use the same basalt fiber volume content 1%.The load-displacement curve(P-δ) on the loading point and load-crack mouth opening displacement curve (P-CMOD)were obtained,and the influence on the fracture property of different seam height ratio,beam depth and span-depth ratio were given.The result shows that with the change of the model’s seam height ratio,height and span-depth ratio,the peak load(Pmax) of the loading point,the maximum crack mouth opening displacement(CMODc),the equivalent critical crack length(ac)and the maximum displacement of loading point (δmax) also present a certain change rule.