Coupled effect of coarse aggregate type and silica fume on creep coefficients of high-strength concrete

Standard concrete creep prediction models are essential for structural design; however, it would be unrealistic to expect accurate prediction results without calibration and validations through experimental studies involving local materials and conditions. This paper reports on the long-term creep of high-strength concrete based on experimental work of six independent concrete mixtures involving three types of aggregate, where three mixtures of them incorporated 10% silica fume. Creep testing was conducted with consideration of standard guidelines for loading and strain measurements for up to 2.5 years. Creep coefficients computed from measured strains indicated a substantial influence of the silica fume and aggregate types. The study found that two of the examined models were capable of producing reasonable predictions of the creep for concretes without silica fume. On the other hand, the a current industry model showed reasonable prediction of the creep of concretes with silica fume while underestimating creep for concretes without silica fume. Finally, a mixed formulation model with features from two of the models is proposed and calibrated for concretes with or without silica fume.