Triaxial Compressive Properties of Graphene Oxide-Modified Concrete

Abstract

Thirty specimens of graphene oxide-modified concrete (GOMC) were prepared with curing age, graphene oxide (GO) dosage, and lateral confining pressure as the test variables. Complete stress–strain curves under triaxial compression were obtained, elucidating the failure mechanism and the effects of these parameters on the peak stress, peak strain, and elastic modulus. The results indicate that the failure modes of GOMC resemble those of ordinary concrete. The triaxial compressive peak stress showed no significant change from 14 to 28 days of curing, whereas the corresponding peak strain decreased. A higher GO dosage increased the peak stress, with a maximum enhancement of 22.4% observed at the optimal dosage of 0.06%, while its effect on peak strain was negligible. Increasing the lateral confining pressure from 0 to 12 MPa altered the failure mode, transitioning from vertical splitting to oblique shear (characterized by pronounced diagonal cracking) and finally to lateral shear. Analysis of variance (ANOVA) quantitatively confirmed that the lateral confining pressure had a more significant effect on strength enhancement than the GO dosage. Empirical formulas for predicting the triaxial peak stress, peak strain, and elastic modulus were developed. Furthermore, a parametric constitutive model was established, which demonstrates good agreement with the experimental data for GOMC under triaxial compression.