Abstract
The constraint ring test is widely used to assess the cracking potential for early-age cementitious materials. In this paper, the analytical expressions based on elastic mechanism are presented to estimate the residual stresses of the restrained mortar ring by considering the comprehensive effects of hydration heat, autogenous and drying shrinkage, creeping, and restraint. In the present analytical method, the stress field of the restrained ring is treated as the superposition of those caused by hydration heat, external restraint, autogenous and drying shrinkage, and creep. The factors including the properties of materials, environmental parameters such as relative humidity and temperature, the geometry effect of specimen, and the relative constraint effects of steel ring to mortar ring, are taken into account to predict the strain development with age of mortar. The temperature of the ring, the elastic modulus, the creep strain, and the split tensile strength are measured to validate the model. The age of cracking is predicted by comparing the estimated maximum tensile stress of the restrained mortar ring with the measured split tensile strength of specimen. The suitability of the present analytical method is assessed by comparing with the restraint ring test and a soundly good agreement is observed.
Highlights
IntroductionThe cementitious materials change volume tremendously in the early-age due to the variations of moisture and temperature, and the chemical reaction
Early-age cracking of cementitious materials has driven great deal of research interests in recent years owing to its contributions in several aspects: the appreciation to the durability issues where cracking plays a dominant role, the advent of high-performance concretes with low water/cement (w/c) ratio which is much more prone to cracking, and the need for rehabilitation and repairing systems which is sensitive to cracks [1,2,3].The cementitious materials change volume tremendously in the early-age due to the variations of moisture and temperature, and the chemical reaction
The mean values of the compressive strength, splitting tensile strength, and elastic modulus of mortar are shown in Figure 3 with respect to mortar age
Summary
The cementitious materials change volume tremendously in the early-age due to the variations of moisture and temperature, and the chemical reaction If restrained, these volumetric changes would result in residual stress development that can lead to cracking [4]. Early-age cracking has been mainly evaluated by qualitative means, which are useful for comparing the sensitivity to cracking of different mixes and additives used to reduce cracking. They are not sufficient for a study of the mechanisms involved, which is an essential step towards developing new strategies and products to harness early-age cracking [8, 9]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
