Effect of Relative Humidity on Absolute and Differential Shortening of Columns and Walls in Multistory Reinforced Concrete Buildings

In tall, multistory reinforced concrete buildings, absolute and differential shortening between adjacent vertical members has become a significant problem during the recent past due to the use of high performance concrete and more advanced design techniques that resulted in smaller member sizes. The failure of nonstructural elements such as claddings has been observed in several structures constructed in the past few decades. The factors that cause these problems could be identified as time-dependent creep and shrinkage coupled with elastic shortening. Both creep and shrinkage depend on the relative humidity of the surrounding environment. This paper discusses the effect of relative humidity on absolute and differential shortening of vertical elements in reinforced concrete buildings.