Effect of temperature on the thixotropic behaviour of self-consolidating concrete

Abstract

The static stability of high fluid concrete (self-consolidating concrete (SCC)) during the dormant period of cement can be improved by using rheological properties. The evolution of the thixotropy of a SCC with temperature ranging from 11°C to 31°C and during the setting time was investigated. A factorial design was carried out to mathematically model the influence of concrete temperature and viscosity-modifying admixture (VMA) dosages on the rheological properties of a SCC. A fixed initial slump flow consistency of 650 ± 10 mm was fixed to more clearly understand the rheological behaviour. A BML type 4 viscometer was employed to characterise the SCC a few minutes after mixing and 30 and 60 min after the first rheological test. It was found that temperature greatly affects the thixotropic behaviour with elapsed time. For high VMA concentrations, the area enclosed by the hysteresis loop is less affected by the temperature. The relevant mechanisms are also discussed based on the analysis of the test results of a factorial experimental plan.