Abstract
Shrinkage, settlement, and thermal deformations of concrete start to develop as soon as the casting is finished. The majority of standard tests currently used to measure free deformations are carried out on hardened concrete. Therefore, the prediction of thermal and other stresses at an early age cannot be determined. This article describes the design and the operation of an experimental device used for measuring the volume change of mortar in relation to the real temperature history. Measurements are carried out on a mortar having a water/cement (W/C) ratio of 0.35 and started approximately 20 min after the addition of water in the mixture up to 24 h of hydration. The measured deformation includes autogenous shrinkage and thermal expansion or contraction caused by the temperature changes induced by the heat of cement hydration. An experimental method is proposed to uncouple these deformations. The investigations show that the autogenous shrinkage amplitude is strongly affected by the temperature history of mortar. Therefore, for a good estimate of the shrinkage amplitudes of cement-based material, temperature must be taken into account in testing.
Highlights
For practical use of cement-based materials, good knowledge of their mechanical behavior is necessary
We present an experimental method that makes a separation of autogenous shrinkage and thermal deformation possible
The first series consists in measuring the volume change of the sample at a constant temperature (20°C)
Summary
For practical use of cement-based materials, good knowledge of their mechanical behavior is necessary. Among others, is a very important property for the good working of a structure since it very often generates either early age cracking (thermal shrinkage and autogenous shrinkage) or late cracking (drying shrinkage). The correct knowledge of the phenomena governing the free deformations of the concrete and the evaluation of their real amplitudes make it possible to avoid cracking and to guarantee a better durability of the structures. The measurement of shrinkage deformations is carried out on hardened concrete. With this test method, the deformations of the freshly mixed concrete are completely ignored and may result in the statement of inaccurate laws of behavior
Sign-in/Register to view highlights & summary 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 callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
