Prediction of early-age compressive strength of epoxy resin concrete using the maturity method

This study is investigated with the prediction of the compressive strength of early-age bisphenol F-type epoxy resin concrete when using the maturity method. When testing the compressive strength of epoxy resin concrete, the strength development started from an age of 20 h at a curing temperature of 0 °C, and the difference between the compressive strengths at the ages of 6 h and 168 h was markedly reduced at a higher curing temperature. Thus, it appeared that the bisphenol F-type epoxy resin concrete was heavily affected by curing temperature. In addition, there were significant differences in strength development based on the hardener type. When calculating the maturity index, it was appropriate to use data up to the age of 72 h, and it appeared that the appropriate value of the constant n is 0.4 in the equation proposed by Ohama, et al. The maturity index was more heavily affected by curing temperature than curing age, and there was a significant difference depending on the hardener type. This study reviewed three prediction models, and when using the dose-response curve model, the coefficient of determination (R2) was the largest, so this is the model that should be used. Although it is possible to apply this model differently based on the hardener type, it was determined that there would be no problem even if a prediction model combining all the test data on the three hardeners was used. In conclusion, when using the prediction model deduced in the study, it was possible to easily predict the early-age compressive strength of bisphenol F-type epoxy resin concrete, and to prove that the maturity method is a non-destructive test useful for cast-in-place applications.