Long-term creep experiment of concrete circular columns with different loading ages was done. The experimental result shows that internal creep coefficient is generally smaller than external creep coefficient, the loading age has great influence on external creep coefficient and little influence on internal creep coefficient. The creep prediction models at home and abroad with short-term loading age （9d） have high predictive accuracy for creep coefficient. The creep prediction models at home and abroad with long-term loading age（39d） have l...
