Meso-level Numerical Analysis Of High Strength And High Performance Concrete

On the mesoscopic level, concrete is simulated as the three-phase materialconsisting of hydrated cement past, aggregate and transition zone between cementand aggregate. For the past decades, people have lauched a deepgoing study on theconcrete material on a macroscopic level. Comparing with the normal concrete, HighStrength and High Performance Concrete (HSHPC) will have a bright future in along run due to its high strength,excellent durability and superior workingperformance, with so many merits, people still haven’t given enough credit to theHSHPC material. Given the current situation, it poses a simulation approach of howthe HSHPC material performs on the microcosmic level in this paper. According tothe data analysis, it will find out the macroscopic mechanical property and thefracture process in a microcosmic way. And it will also establish a multi-phasesconnection between microcosmic and macroscopic scale in order to conduct a deeperstudy on the fracture mechanism of the HSHPC material. The main contents in thispaper are as follows:(1) Based on the random nature of the aggregate distribution and morphology,Walraven formula is applied here to determine the convex polygonal aggregatedistribution of two-dimensional concrete specimen cross-section. It puts forward aconvex polygon algorithm in which the round aggregate area is the controlparameters and the inscribed polygon to round aggregate is the frame.(2) The mesoscopic components of each phase are endowed with thecorresponding mechanical parameter in the finite element analysis by the ANSYS.The APDL progamming language is used to compile the calculation application. In this application, it forms a series of sample number of the HSHPC material used toconduct the numerical experiments.(3) Taking the concrete with the strength of80Mpa for example, it poses asimulation with the numerical specimen under the uniaxial load to form thecorresponding stress-strain curve and the figure of damage element. Comparing thesimulation result with the practical experimental data, it indicates that the datasimulation is correct and reliable. To push further, the data specimen is used toconduct a numerical experiment of the uniaxial compression and tension. In this case,the macroscopic mechanical property of the concrete can be studied profoundly bythe change of the aggregate and mortar mechanical parameters. It tells that thestrength of the HSHPC material can be effectively enhanced by the strength increaseof the aggregate.Based on the mesoscopic numerical analysis, it provide a solid theoryfoundation to the study of the HSHPC material in this paper,which could supply agreat convenience for the understanding of the concrete internal action and areference for the mechanical property of the concrete under the complex forcecondition.