Strength Development of High Strength High-Performance Concrete at Early Ages

摘要

This study aims to investigate the characteristics of the early strength development of HPC. Experimental tests were conducted on concrete with a 28 days' strength of 56 Mpa starting from 6 hours after mixing. The test methods include ultrasonic pulse velocity measurement and maturity method in addition to the standard compression test. Seven curing ages (6hrs, 12hrs, 1day, 2days, 3days, 7days and 28days) were selected for the tests. Test results show that the increase rates of the strength growth of HPC are significantly different before and after 1 day of curing age. By selecting the curing age of 1 day as the separating point, a prediction model is proposed to describe the strength development in the two separated stages and is further verified by the tests. Moreover, compared to the test results, it is found that the prediction model releases better agreement than those obtained from the method of maturity.