A Review and Comparative Study of Existing Shrinkage Prediction Models for Portland and Non-Portland Cementitious Materials

Abstract

This paper reviews shrinkage prediction models for cementitious materials and presents analysis of selected published data utilizing the aforementioned models. The main objective of this review is to revisit and reexamine the primary shrinkage mechanisms, that is, capillary pressure theory, Gibbs-Bangham shrinkage, and withdrawal of disjoining pressure in Portland and non-Portland cement. In particular, the theoretical basis for current shrinkage models is elaborated on and its soundness and applicability to explain the published experimental data are discussed. Additionally, a specific comparison was made among high water-to-cement (w/c) ratio ordinary Portland cement (OPC), low w/c OPC, and alkaline activated slag.

Quantitative Analysis of Phase Assemblage and Chemical Shrinkage of Alkali-Activated Slag

“…On the other hand, many researchers have shown that AAS has significantly higher shrinkage (both autogenous and drying) than OPC Neto et al 2008;Ye and Radlińska 2016). These large deformations can lead to concrete durability issues, as cracking is expected to occur when volumetric changes are restrained.…”

Mitigation of Drying and Carbonation Shrinkage of Cement Paste using Magnesia

“…In addition, the incorporation of MgO barely affects the moisture loss of HCP, which may imply that the pore structure of HCP keeps relatively unchanged due to MgO addition. According to the basic principle of capillary pressure theory, the amount of moisture loss in drying cementitious materials is mainly controlled by the drying relative humidity, water activity and surface tension of pore solution, as well as pore size distribution (Ye and Radlińska 2016b). Given that the properties of pore solution in cementitious materials merely change considerably with organic compound incorporation such as surfactants, they are believed to remain relatively constant due to MgO addition (also supported by the thermodynamic modeling).…”

Bonded Concrete Overlays: A Brief Discussion on Restrained Shrinkage Deformations and Their Prediction Models

“…1and (2) can be rewritten and formulated ultimately as for instance in Eq. 4 [21]. Other approach has been presented in [42], where the deformation of the solid body at time t εs.ex(t) was given as in Eq.…”

“…However, according to the authors' knowledge, there is no precise explanation of this behaviour. Ye [21] suggested two possible reasons: firstly, the saturation degree Sw (Eq. 4) assumes the existence of water only in capillary form, while for low w/c higher water content may be contained in nano and gel pores, where capillary theory is not applicable.…”

“…4) assumes the existence of water only in capillary form, while for low w/c higher water content may be contained in nano and gel pores, where capillary theory is not applicable. Secondly, a possible solution given in [21] is that the viscoelastic response during desiccation (also influenced by w/c) is overwhelming in comparison with shrinkage. Thus, it is probable that the structural effects of specimens' size are in fact affecting the external measurement.…”