Sachraa Ganggamuren Borjigin - Academia.edu (original) (raw)
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Papers by Sachraa Ganggamuren Borjigin
Proceedings of the 3rd ACM SIGSPATIAL International Workshop on GeoSpatial Simulation, 2020
Transportation Research Part D: Transport and Environment, 2022
CONCREEP 10, 2015
In this work, we analyzed x-ray microtomographic images to quantify the porosity of small mortar ... more In this work, we analyzed x-ray microtomographic images to quantify the porosity of small mortar specimens, with a particular focus on the porosity of the interfacial transition zone (ITZ). Specimens were nominally 5 mm diameter, 4 mm long cylinders with 0.5 mm diameter glass bead aggregates. Specimens were scanned via synchrotron-based x-ray microtomography while they were positioned in an in situ loading frame in a split cylinder configuration. Scans of undamaged specimens were evaluated for porosity both in the bulk paste and in the ITZ. Specifically, voids in the paste and porosity in the ITZ were superimposed onto a map of the tensile stress in the specimen in an attempt to identify critical flaws, and to measure their role in split cylinder strength. Preliminary results indicate that the ITZ porosity has a lower effect on split cylinder strength than the large flaws that occur either in the ITZ or the bulk cement past. INTRODUCTION Properties of the interfacial transition zone (ITZ) in concrete have long been recognized as critical to both transport properties and mechanical properties (e.g. Buyukozturk and Wecharatana 1995). The high porosity characteristic of the ITZ can provide a critical flaw that can dictate fracture toughness, as well as provide a path of least resistance for fluid transport. Despite its importance, high quality 3D quantitative measurements of ITZ porosity have been limited. In this work, we have employed x-ray microtomography to make 3D measurements of porosity around artificial aggregates in a cement matrix. Within the resolution of the imaging technique, we are able to quantify porosity with respect to distance from the aggregate and spatial variation relative to casting direction and load axis. We are also able to look at the spatial variation of interface porosity in the zone of maximum split cylinder tension to partially examine variability of split cylinder strength. Finally, we are able to identify preferential pathways for mass transport via interfaces and shortest matrix distances. The focus of the work described here is an analysis of voids in both the bulk cement past and the ITZ, and to assess the relative importance of the voids with respect CONCREEP 10 408
Journal of Nanomechanics and Micromechanics, 2016
Proceedings of the 3rd ACM SIGSPATIAL International Workshop on GeoSpatial Simulation, 2020
Transportation Research Part D: Transport and Environment, 2022
CONCREEP 10, 2015
In this work, we analyzed x-ray microtomographic images to quantify the porosity of small mortar ... more In this work, we analyzed x-ray microtomographic images to quantify the porosity of small mortar specimens, with a particular focus on the porosity of the interfacial transition zone (ITZ). Specimens were nominally 5 mm diameter, 4 mm long cylinders with 0.5 mm diameter glass bead aggregates. Specimens were scanned via synchrotron-based x-ray microtomography while they were positioned in an in situ loading frame in a split cylinder configuration. Scans of undamaged specimens were evaluated for porosity both in the bulk paste and in the ITZ. Specifically, voids in the paste and porosity in the ITZ were superimposed onto a map of the tensile stress in the specimen in an attempt to identify critical flaws, and to measure their role in split cylinder strength. Preliminary results indicate that the ITZ porosity has a lower effect on split cylinder strength than the large flaws that occur either in the ITZ or the bulk cement past. INTRODUCTION Properties of the interfacial transition zone (ITZ) in concrete have long been recognized as critical to both transport properties and mechanical properties (e.g. Buyukozturk and Wecharatana 1995). The high porosity characteristic of the ITZ can provide a critical flaw that can dictate fracture toughness, as well as provide a path of least resistance for fluid transport. Despite its importance, high quality 3D quantitative measurements of ITZ porosity have been limited. In this work, we have employed x-ray microtomography to make 3D measurements of porosity around artificial aggregates in a cement matrix. Within the resolution of the imaging technique, we are able to quantify porosity with respect to distance from the aggregate and spatial variation relative to casting direction and load axis. We are also able to look at the spatial variation of interface porosity in the zone of maximum split cylinder tension to partially examine variability of split cylinder strength. Finally, we are able to identify preferential pathways for mass transport via interfaces and shortest matrix distances. The focus of the work described here is an analysis of voids in both the bulk cement past and the ITZ, and to assess the relative importance of the voids with respect CONCREEP 10 408
Journal of Nanomechanics and Micromechanics, 2016