Abstract:Uniaxial， biaxial， conventional triaxial and true triaxial compression tests were conducted on plastic concrete to investigate the effects of different loading conditions on the dilatation characteristics and failure mechanism of the specimens. The results indicate that under different loading conditions， the specimen exhibits dilatation before reaching its peak， which is a precursor to specimen failure. The dilatation value of the sample is related to the material properties and the size of the lateral limit. The greater the strength of the material， the smaller the dilatation value. The stronger the lateral constraint， the greater the dilatation value and strength of the specimen. After the peak of the stress-strain curve of the dilated sample， the deformation shows softening or plasticization characteristics， while the stress-strain curve of the non-expanded sample shows hardening characteristics after the peak. The lateral strain expansion of the specimen first occurs in the direction of lower lateral stress. When the dilatation occurs in the direction of higher lateral stress， the specimen is about to dilate. The dilatation of lateral strain can be used as a basis for predicting the dilatation of the specimen.
