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Title: A dissolution-precipitation mechanism is at the origin of concrete creep in moist environments

Abstract

Long-term creep (i.e., deformation under sustained load) is a significant material response that needs to be accounted for in concrete structural design. However, the nature and origin of concrete creep remain poorly understood and controversial. Here, we propose that concrete creep at relative humidity ≥ 50%, but fixed moisture content (i.e., basic creep), arises from a dissolution-precipitation mechanism, active at nanoscale grain contacts, as has been extensively observed in a geological context, e.g., when rocks are exposed to sustained loads, in liquid-bearing environments. Based on micro-indentation and vertical scanning interferometry data and molecular dynamics simulations carried out on calcium–silicate–hydrate (C–S–H), the major binding phase in concrete, of different compositions, we show that creep rates are correlated with dissolution rates—an observation which suggests a dissolution-precipitation mechanism as being at the origin of concrete creep. C–S–H compositions featuring high resistance to dissolution, and, hence, creep are identified. Analyses of the atomic networks of such C–S–H compositions using topological constraint theory indicate that these compositions present limited relaxation modes on account of their optimally connected (i.e., constrained) atomic networks.

Authors:
 [1];  [2];  [3];  [4];  [5];  [1];  [6]
  1. Laboratory for the Chemistry of Construction Materials (LC2), Department of Civil and Environmental Engineering, University of California, Los Angeles, California 90095 (United States)
  2. Materials Science and Engineering Department, Missouri University of Science and Technology, Rolla, Missouri 65409 (United States)
  3. Giatec Scientific, Ottawa, Ontario K2H 9C4 (Canada)
  4. Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831 (United States)
  5. Physics of AmoRphous and Inorganic Solids Laboratory (PARISlab), Department of Civil and Environmental Engineering, University of California, Los Angeles, California 90095 (United States)
  6. (CNSI), University of California, Los Angeles, California 90095 (United States)
Publication Date:
OSTI Identifier:
22679032
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Chemical Physics; Journal Volume: 145; Journal Issue: 5; Other Information: (c) 2016 Author(s); Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; CONCRETES; CREEP; EXPERIMENTAL DATA; MOLECULAR DYNAMICS METHOD

Citation Formats

Pignatelli, Isabella, Kumar, Aditya, Alizadeh, Rouhollah, Le Pape, Yann, Bauchy, Mathieu, E-mail: bauchy@ucla.edu, E-mail: gsant@ucla.edu, Sant, Gaurav, E-mail: bauchy@ucla.edu, E-mail: gsant@ucla.edu, and California Nanosystems Institute. A dissolution-precipitation mechanism is at the origin of concrete creep in moist environments. United States: N. p., 2016. Web. doi:10.1063/1.4955429.
Pignatelli, Isabella, Kumar, Aditya, Alizadeh, Rouhollah, Le Pape, Yann, Bauchy, Mathieu, E-mail: bauchy@ucla.edu, E-mail: gsant@ucla.edu, Sant, Gaurav, E-mail: bauchy@ucla.edu, E-mail: gsant@ucla.edu, & California Nanosystems Institute. A dissolution-precipitation mechanism is at the origin of concrete creep in moist environments. United States. doi:10.1063/1.4955429.
Pignatelli, Isabella, Kumar, Aditya, Alizadeh, Rouhollah, Le Pape, Yann, Bauchy, Mathieu, E-mail: bauchy@ucla.edu, E-mail: gsant@ucla.edu, Sant, Gaurav, E-mail: bauchy@ucla.edu, E-mail: gsant@ucla.edu, and California Nanosystems Institute. Sun . "A dissolution-precipitation mechanism is at the origin of concrete creep in moist environments". United States. doi:10.1063/1.4955429.
@article{osti_22679032,
title = {A dissolution-precipitation mechanism is at the origin of concrete creep in moist environments},
author = {Pignatelli, Isabella and Kumar, Aditya and Alizadeh, Rouhollah and Le Pape, Yann and Bauchy, Mathieu, E-mail: bauchy@ucla.edu, E-mail: gsant@ucla.edu and Sant, Gaurav, E-mail: bauchy@ucla.edu, E-mail: gsant@ucla.edu and California Nanosystems Institute},
abstractNote = {Long-term creep (i.e., deformation under sustained load) is a significant material response that needs to be accounted for in concrete structural design. However, the nature and origin of concrete creep remain poorly understood and controversial. Here, we propose that concrete creep at relative humidity ≥ 50%, but fixed moisture content (i.e., basic creep), arises from a dissolution-precipitation mechanism, active at nanoscale grain contacts, as has been extensively observed in a geological context, e.g., when rocks are exposed to sustained loads, in liquid-bearing environments. Based on micro-indentation and vertical scanning interferometry data and molecular dynamics simulations carried out on calcium–silicate–hydrate (C–S–H), the major binding phase in concrete, of different compositions, we show that creep rates are correlated with dissolution rates—an observation which suggests a dissolution-precipitation mechanism as being at the origin of concrete creep. C–S–H compositions featuring high resistance to dissolution, and, hence, creep are identified. Analyses of the atomic networks of such C–S–H compositions using topological constraint theory indicate that these compositions present limited relaxation modes on account of their optimally connected (i.e., constrained) atomic networks.},
doi = {10.1063/1.4955429},
journal = {Journal of Chemical Physics},
number = 5,
volume = 145,
place = {United States},
year = {Sun Aug 07 00:00:00 EDT 2016},
month = {Sun Aug 07 00:00:00 EDT 2016}
}
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