MULTISCALE MODELING OF ALKALI SILICA REACTION DEGRADATION OF CONCRETE

Author(s): Gianluca Cusatis, Mohammed Alnaggar and Roozbeh Rezakhani
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: 431-438
Total Pages: 8
Language: English

Abstract: Concrete infrastructures, especially those subject to wet environments (R.H. > 80%) are usually endangered by Alkali silica reaction (ASR). Inside concrete meso-structure, water transports alkali ions from cement paste into the aggregate, which react with the available non-crystalline silica inside each aggregate piece. The reaction product (ASR gel) imbibes additional water causing swelling and cracking, resulting in degradation of concrete mechanical properties. ASR is a complex, multi-scale chemo-mechanical problem driven by various environmental factors including humidity and temperature. The physics involved in diffusion and permeability inside concrete play a fundamental role in defining the kinematics, rate and extent of ASR. This paper extends the ASR-LDPM model which models ASR at the aggregate level to account for variable humidity conditions and combines the mechanical behavior of concrete with ASR, creep and shrinkage induced deformations. Finally, to solve large-scale structures, this micro-scale process is coupled into the Homogenized Lattice Discrete Particle Model (H-LDPM), which is a constitutive equation obtained by the mathematical homogenization of LDPM, a discrete model capturing various features of concrete internal heterogeneity with superior modeling and predictive capabilities under various quasi-static and dynamic loading. The capabilities of this approach are validated with reference to experimental data from the literature.

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