Creep Rupture Of Concrete Under Sustained Uniaxial Compression

Creep of concrete material is an important mechanics performance related to time,which is a generally slow deformation process of concrete material under long-term load.It will affect the overall safety of the structure and lead to macroscopic structure damage.Based on that, this paper mainly explores the concrete creep damage characteristic andcritical precursor behavior before destruction.By means of a large number of tests, experiment observed two typical creepprocesses, a sample of concrete creep damage did not occur in the process, the nother wasdisastrous rupture during creep.Through statistical analysis of the experimental datum, three typical stages of creepfailure process were observed, that is the initial rapid creep stage, stable creep stage,accelerating creep stage. Statistical analysis show that creep damage time exist obviousdiscreteness, but close to damage point, strain rate with time evolution presented a criticalpower law behavior and the power index close to-2/3. Based on statistical creepdeformation values obtained in steady creep stage, the strain rate deformation is nearlyconstant; strain rate deformation corresponding to the minimum point of the slopeincreases as time; destruction slope is proportional to the time; there is no obvious relationbetween compressive strength and failure modes. After the destruction of macro-crackedconcrete specimens, Macro cracks are mainly two forms: one is a single diagonal crackalong the rupture surface; the other is "X" type crack along the two diagonal directions. Bythree-dimensional finite element simulation, the evolution of the axial deformation and theaxial deformation rate of the concrete during creep deformation were analyzed.