Influence Of Specimen Thickness On Uniaxial Compressive Damage In Uniaxial Compressive Test

Thickness of specimen has a great influence on the mechanical properties of plastic concrete,however the current study is not perfect.In order to further promote application of plastic concrete material,it is necessary to research on the content.We make four different groups include five kinds of ratio of high to width(1,2,3,3.7 and 5)specimens of plastic concrete for the question.Through uniaxial compression stress-strain curve experiment,finding the influence of height on the deformation distribution and strength of different layers in the specimen.Analysisng the same test by using the model of Concrete Damaged Plasticity with ABAQUS.We can get some results:In the uniaxial compressive test,the results show that thickness has great influence on failure performance,axial and lateral deformation,but has little effect on peak strength and peak deformation.Plastic concrete behaviors as expansion-shear failure under uniaxial compressive stress,and the maximum shear cracks are 3 specimen's width,and it occurs on the specimen's fixed end.Deformation in the length of the specimen is not uniform during the loading of force.In the uniaxial compressive test,the axial deformation of different layers in the specimen is non-uniform,closely relating to the height of the specimen and the loading process.When the ratio of length to width of specimen is more than 3,axial deformation mainly occurs at the loading end in the process of increasing the approximate linear load;but the increase of axial deformation mainly occurs at the fixed end,and the deformation at the loading end decreases rapidly in the process of increasing and decreasing of the load curve.When the ratio of length to width of specimen is between 2 and 3,axial deformation mainly occurs at the one end in the process of increasing the approximate linear load;but the increase of axial deformation mainly occurs at the other.The height of specimen has a great influence on the lateral deformation of plastic concrete under uniaxial compression,and the lateral deformation of the specimen is non-uniform.The lateral deformation of the specimen is small in the process of the approximate straight increasing line,and during the increase and decrease of the load curve,the lateral deformation increases rapidly,which is mainly located at the fixed end.When the height to width ratio is greater than 3 times,the trend is more significant.The effect of specimen height on the peak stress and peak deformation of plastic concrete under uniaxial compression is small.When the ratio of height to width is greater than 2 times,the peak stress and peak deformation are basically stable,and do not change with the increase of height.The results of numerical simulation are similar to the measured results.With the increase of height to width ratio,the axial and lateral deformations are distributed unevenly.The inhomogeneity of the plastic concrete leads to the non-uniform deformation under the action of force,which may result in the local damage of the larger and larger specimens.