Title: Effect of Admixtures on Mechanism of Plastic Shrinkage Cracking in Self-Consolidating Concrete
Author(s): Faez Sayahi, Mats Emborg, Hans Hedlund, and Andrzej Cwirzen
Publication: Materials Journal
Appears on pages(s): 51-59
Keywords: admixtures; cracking; plastic settlement; plastic shrinkage; self-consolidating concrete (SCC)
This research studies the effect of retarder, accelerator, stabilizer, air-entraining agent, and shrinkage-reducing admixture (SRA) on plastic shrinkage cracking in self-consolidating concrete (SCC). The main objective is to identify the dominant cracking cause—that is, plastic settlement or plastic shrinkage—in an SCC containing a particular admixture. During experimentation, crack-free concretes were achieved by adding air-entraining agent and SRA, while accelerator and retarder increased the crack area. The impact of admixtures on the cracking mechanism was identified by comparing the respective vertical and horizontal deformations. It was observed that the crack-free concretes had moderate settlement and horizontal shrinkage, while the cracked specimens exhibited significant deformation either vertically or horizontally.