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Title: Micromechanical Response of Crystalline Phases in Alternate Cementitious Materials using 3-Dimensional X-ray Techniques
Abstract

Cementitious materials are complex composites that exhibit significant spatial heterogeneity in their chemical composition and micromechanical response. Modern 3-dimensional characterization techniques using X-rays from synchrotron light sources, such as micro-computed tomography (μCT) and far-field high-energy diffraction microscopy (ff-HEDM), are now capable of probing this micromechanical heterogeneity. In this work, the above mentioned techniques are used to understand the varying micromechanical response of crystalline phases (cubic iron oxide andα-quartz) inherently present within an alkali-activated fly ash (AAF) duringin-situconfined compression. A subset of the crystals probed using ff-HEDM are registered with the tomographic reconstructions and tracked through the applied loads, highlighting the combination ofμCT and ff-HEDM as a means to examine both elastic strain in the crystalline particles (and by extension local stress response) and plastic strain in the matrix. In this study, significant differences in the load carrying behaviors of the crystalline phases were observed wherein the cubic iron oxide crystals laterally expanded during the confined compression test, while theα-quartz particles laterally contracted and at the final load step, shed load likely due to failure in the surrounding matrix. Finally, the two characterization techniques are discussed in terms of both advantages and associated challenges for analysis of multi-phase cementitious materials.

 
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NSF-PAR ID:
10153870
Author(s) / Creator(s):
; ;
Publisher / Repository:
Nature Publishing Group
Date Published:
Journal Name:
Scientific Reports
Volume:
9
Issue:
1
ISSN:
2045-2322
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
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