Abstract
In the previous paper, an analytical condition to do the prediction of a realistic early age crack in the RC box culvert was examined. However, the examined analytical condition is not verified with two or more structures. In this paper, the analytical condition which had been obtained by the previous paper is reexamined by three RC box culverts where a structural scale, a mixing of concrete, and the placing time were different. As a result, the analytical result of early age crack in three RC box culverts was different from the generative situation of measured crack, though the result of obtaining by previous paper had been applied. This cause is relative humidity used to presume drying shrinkage strain, relative humidity should input not actual relative humidity but an opposite value on the equation to presume drying shrinkage strain in JSCE. In this paper, a new equation to presume drying shrinkage strain using for the early age crack analysis in the concrete structure with long one direction was proposed.