Deformation capacity of fresh cement pastes

Abstract

The deformation capacity conditions several processes in cement-based materials, including workability and structural build-up. However, the origins of this deformation capacity present some ambiguities. This paper aims to contribute to improving the comprehension of the deformation capacity of fresh cement pastes. For this, the effect of water-to-cement ratio (w/c) and superplasticizer (SP) dosage on the viscoelastic properties of cement paste is examined using oscillatory rheology and yield stress measurements. It appears that water to cement ratio affects slightly the critical strain at the end of the linear viscoelastic domain (LVED) and strongly the storage modulus. The addition of superplasticizer seems to have a strong effect on the critical strain. In addition, it was shown that the critical strain at the end of the LVED is associated with strong physical forces (colloidal forces enhanced by early hydrates formation), while the transition strain at the flow onset is due to large structural reorganizations.