Location
the Sixth International Conference on Durability of Concrete Structures (ICDCS 2018) which will be held in Leeds, UK
Event Website
https://engineering.leeds.ac.uk/icdcs2018/
Keywords
Alkali- Silica Reaction (ASR), a novel multiscale approach, concrete structures; expansion prediction
Abstract
This paper presents a new multiscale approach for evaluation of the volume change in concrete structures due to the alkali-silica reaction (ASR). A practical step by step approach that can be applied to the real structures is developed based on combined experimental and numerical assessment by considering the most influential ASR parameters at different scales. In the first step, the ASR expansion is measured using accelerated concrete cylinder test (ACCT) for different concrete mixtures covering different variables of important factors such as mix design (e.g., w/cm, fly ash type and replacement percentages), aggregate reactivity, alkali loadings, temperature, and relative humidity etc. All measured expansion data are then modelled using artificial neural network (ANN) modeling approach in the second step. In the third step, finite element (FE) model is utilized at different scales to analyze the real structures and representative volume element (RVE) taking into account the ASR gel expansion and structural boundary conditions. Finally, the effects of the structural constraints are taken into account by introducing correction factors to the predicted free expansion (i.e. no constraints) of the RVE by ANN model. It was found that a combined effect of both internal gel pressure and structural constraints determines the net volume expansion in a concrete structure. In order to show the applicability of the proposed approach, the model is employed for evaluation of the ASR-induced net volume expansion at different locations of a dam structure under realistic in-service conditions. The microstructural study was also done by using X-ray CT that can be used to estimate the ASR progress in concrete structure and validate / support the FEM based predictions.
Revised Paper along with responses for the reviewer's comments
Response to Reviewers' Comments.pdf (237 kB)
Responses to the reviewer's comments
ICDCS-2018-paper-Multiscale-modeling-ASR-Final-revised.pdf (591 kB)
Included in
A Novel Multiscale Modelling Approach for Evaluation of the ASR in Concrete Structures
the Sixth International Conference on Durability of Concrete Structures (ICDCS 2018) which will be held in Leeds, UK
This paper presents a new multiscale approach for evaluation of the volume change in concrete structures due to the alkali-silica reaction (ASR). A practical step by step approach that can be applied to the real structures is developed based on combined experimental and numerical assessment by considering the most influential ASR parameters at different scales. In the first step, the ASR expansion is measured using accelerated concrete cylinder test (ACCT) for different concrete mixtures covering different variables of important factors such as mix design (e.g., w/cm, fly ash type and replacement percentages), aggregate reactivity, alkali loadings, temperature, and relative humidity etc. All measured expansion data are then modelled using artificial neural network (ANN) modeling approach in the second step. In the third step, finite element (FE) model is utilized at different scales to analyze the real structures and representative volume element (RVE) taking into account the ASR gel expansion and structural boundary conditions. Finally, the effects of the structural constraints are taken into account by introducing correction factors to the predicted free expansion (i.e. no constraints) of the RVE by ANN model. It was found that a combined effect of both internal gel pressure and structural constraints determines the net volume expansion in a concrete structure. In order to show the applicability of the proposed approach, the model is employed for evaluation of the ASR-induced net volume expansion at different locations of a dam structure under realistic in-service conditions. The microstructural study was also done by using X-ray CT that can be used to estimate the ASR progress in concrete structure and validate / support the FEM based predictions.
https://docs.lib.purdue.edu/icdcs/2018/dsm/11
