Considering the effect of the randomness of concrete strength and relative humidity on concrete creep

Experimental research on concrete creep with different strengths under various ambient relative humidity was carried out. Based on certainty creep models provided in CEB-FIP Model Code 1990 and Model Code 2010, the Latin hypercubic sampling method was used to establish uncertainty models of concrete creep, and the sensitivity of concrete strength and ambient relative humidity to models was analyzed. Experimental results show that the creep coefficient has a negative correlation with concrete strength and ambient relative humidity, and the latter influences creep more than the former. In addition, the sensitivity of ambient relative humidity and concrete strength for CEB-FIP MC 90 and MC 2010 models changes with the variation of coefficients. Under different environmental conditions, there is deviation between the tested creep coefficients and theoretical values by certainty creep models, while the experimental data are within the 95% confidence interval of CEB-FIP MC 90 model, indicating that the presented numerical method for calculating the 95% confidence interval of the creep coefficient is reliable.