Recovery of creep and observations on the mechanism of creep of concrete

Summary Test data on the recovery of creep of mortar specimens made with different cements are presented. It is shown that, whereas creep depends on the strength of mortar (as influenced by the cement), the creep recovery is not a function of this strength. From measurements on the change in weight of specimens, under load and free-standing, it is concluded that creep is not caused by the movement of water from the cement paste into the surrounding medium. The possibility of creep being connected with the removal of zeolitic water from calcium silicate hydrates is discussed, and reasons for the non-reversible character of creep recovery are suggested.