MODELLING SHRINKAGE AND THERMAL DEFORMATIONS IN HIGH PERFORMANCE CONCRETE AT EARLY AGE

Author(s): Mateusz Wyrzykowski, Dariusz Gawin, Pietro Lura
Book Title: RILEM International Symposium on Concrete Modelling - CONMOD 2014
Editor: Kefei Li, Peiyu Yan and Rongwei Yang
ISBN: 978-2-35158-139-1
e-ISBN: 978-2-35158-140-7
Publisher: RILEM Publications SARL
Publication year: 2015
Pages: 127-134
Total Pages: 8
Language: English

Abstract: High Performance Concrete (HPC) undergoes a decrease in the internal relative humidity (RH) both due to self-desiccation and drying. The resulting shrinkage can lead to micro- or macro-cracking already at early stages of hardening. At the same time, an increase of temperature occurs in the concrete elements due to release of heat of hydration (self-heating), which leads to the buildup of thermal stresses and possibly to cracking. It has been shown that the thermal expansion coefficient (CTE), a key factor in terms of thermal stresses buildup, is coupled with the evolution of the hygral state of the concrete, especially for HPC with low water-to-cement ratio and fine pore structure. Since the CTE increases considerably with the decrease of the internal RH, thermal and hygral strains need to be considered together while assessing the deformations of the concrete. In this work we use a poromechanical model for the description of the coupled evolution of the hygral state, governed both by self-desiccation and drying, and the thermal state, governed by the evolution of the hydration process. At the same time, the effect of internal curing, which reduces both the hygral and the thermal deformations, is introduced into the model.

Online publication: 2015
Publication Type: full_text
Public price (Euros): 0.00