Mathematical Model for Early-Aged UHPFRC Compressive Strength Changes

Compressive strength is the most important mechanical index of ultra-high performance fiber-reinforced concrete (UHPFRC). The rule changes in compressive early-aged UHPFRC great significance to guide curing, formwork removal, and prestress stretching. Therefore, it very necessary study an accurate mathematical model describe change at early age. For this purpose, a new age proposed work for predicting long-term according few test data from UHPFRC. This can overcome shortcomings existing models, such as exponential model, logarithmic polynomial model. first demonstrated by using four groups compiled previous research studies. Subsequently, experiment was carried out further verify mixed proportion used 10.87:0.82:1 (powder:steel fiber:water), design grade 120 MPa. Based on experimental data, shown that average fitting error standard deviation were about 10%~20% precisely predict UHPFRC, with determination coefficient (R2) 0.9974. results show significantly reduced when compared predicted 60th day closest actual concrete. greatest advantage method lies its simple formula, fast implementation, no need complex operations. It has been superior models due higher accuracy prediction accuracy, be better later only taken stage.