Investigation of shrinkage behaviour and cracks in cement paste using moiré interferometry

Abstract

This paper focuses on using the cure reference method (CRM), which was previously developed for the measurement of residual strains in composites, to determine the shrinkage that develops in cementitious materials. The experimental technique involves both the replication of diffraction grating on the cement paste specimen during the curing process and the use of high-sensitivity moiré interferometry. An automated fringe analysis system was developed and applied to obtain the full-field displacement and strain information on the surface of the specimen. Overall shrinkage as a function of time, location, and surrounding drying conditions was measured. Moreover, a method of combining CRM and the sealing of the entire specimen was used to investigate the contribution of chemical shrinkage. Chemical shrinkage as a function of water/cement (w/c) ratio, temperature, and time was explored. The experimental results demonstrate the same trends of shrinkage behaviour as documented in the literature. Furthermore, the ring test was performed to investigate shrinkage-induced cracks.

Deformation behaviors of cemented backfill using sulphide-content tailings

“…In cementitious materials, the overall shrinkage is primarily attributed to the drying effect (drying shrinkage) and chemical reaction between water and cement (chemical shrinkage or non-drying shrinkage) (Chen et al, 2010). In view of a previous experimental study (Chen et al, 2010;Deng et al, 2012), the shrinkage ratio of cemented tailings materials would be stable over 7 days. In this study, the dimension of curing for 7 days ( 7 ) was defined as initial size.…”

Influence of Thickness on Residual Stress Profile in Veneering Ceramic Layered: Measurement by Hole-Drilling

“…The strain-gaue method, however, presents a number of inherent drawbacks widen used to measure strain gradients such as those liberated around a drilled hole. The possibility of replacing the traditional strain-gage rosette with a full-field coherent optics technique is discussed in several recent papers: holographic interferometry is examined in Refs [4].and moire interferometry is examined in Refs [5,6].The potential of these techniques appears best exploited when measurements are performed in nonconventional situations(i.e, presence of stress gradients, measurements on small components).…”