Mesoscale Modeling of Nonlinear Influence of Ambient Relative Humidity on Drying Shrinkage of Concrete

Abstract:

Creep and shrinkage are complicated time-dependent processes taking place in cementitious materials. In typical concretes, the most significant part of shrinkage is represented by drying shrinkage; it is caused by a decrease in relative humidity of pores which leads to an increase in capillary tension of pore water and in the solid surface tension at pore walls.Experimental data indicate that the ultimate value of drying shrinkage measured on concrete and mortar specimens is a nonlinear function of the ambient relative humidity. The nonlinear behavior is partially caused by microcracking, and partially by creep of the cement matrix. On the other hand, drying shrinkage of hardened cement paste, measured on very thin specimens at gradually decreasing relative humidity, is found to be a linear function of relative humidity.The aim of this paper is to assess the nature of the macroscopic shrinkage computed employing finite element simulations at the meso-scale level in which the drying cement paste is described by a viscoelastic model with tensile cracking and with a constant shrinkage coefficient.

• Periodical: Applied Mechanics and Materials (Volume 825)
• Pages: 129-134
• DOI: https://doi.org/10.4028/www.scientific.net/AMM.825.129
• Online since: February 2016
• Authors: Petr Havlásek*, Milan Jirásek
• Keywords: Concrete, Creep, Finite Elements, Modeling, Shrinkage

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