A platform for research: civil engineering, architecture and urbanism
A platform for research: civil engineering, architecture and urbanism
The visualization of water transport through hydrophobic polymer coatings applied to building sandstones by broad line magnetic resonance imaging
It is shown that broad line gradient echo magnetic resonance imaging (MRD) is an ideal tool with which to study the ingress of hydrophobic polymer surface treatments into porous building materials, specifically in this case sandstone. It is further shown that the method can be used to quantitatively visualize the movement of water into and through the treated material, both from the surface and bulk, as a function of time. The influence of treatment cure time, cure temperature and substrate hydration on the subsequent water transport have been investigated. For the first time direct evidence of water pumping through a treated surface is presented. Specifically related to sandstone, it is shown that the treatment applied in this work was ineffective if cure is at modest temperature for modest times. The treatment barrier efficiency was clearly demonstrated to increase with curing time and particularly temperature. It was also shown to be sensitive to the hydration state of the substrate at the time of cure. However, it has been shown that water will go through even well-cured treatment eventually. For the first time, clear and unambiguous evidence of 'water pumping' from the surface of a stone sample, through the treatment surface layer and into dry stone beyond has been obtained. This has considerable implications for the durability of treated sandstones under freeze-thaw conditions. Whilst many of these conclusions have been suspected within the building industry for some considerable time, and whilst there has been consequent concern as to the cost effectiveness of applying these treatments as a matter of course, as now often required, this is the first time that a direct measurement procedure which can be used to assess treatments has been demonstrated.
The visualization of water transport through hydrophobic polymer coatings applied to building sandstones by broad line magnetic resonance imaging
It is shown that broad line gradient echo magnetic resonance imaging (MRD) is an ideal tool with which to study the ingress of hydrophobic polymer surface treatments into porous building materials, specifically in this case sandstone. It is further shown that the method can be used to quantitatively visualize the movement of water into and through the treated material, both from the surface and bulk, as a function of time. The influence of treatment cure time, cure temperature and substrate hydration on the subsequent water transport have been investigated. For the first time direct evidence of water pumping through a treated surface is presented. Specifically related to sandstone, it is shown that the treatment applied in this work was ineffective if cure is at modest temperature for modest times. The treatment barrier efficiency was clearly demonstrated to increase with curing time and particularly temperature. It was also shown to be sensitive to the hydration state of the substrate at the time of cure. However, it has been shown that water will go through even well-cured treatment eventually. For the first time, clear and unambiguous evidence of 'water pumping' from the surface of a stone sample, through the treatment surface layer and into dry stone beyond has been obtained. This has considerable implications for the durability of treated sandstones under freeze-thaw conditions. Whilst many of these conclusions have been suspected within the building industry for some considerable time, and whilst there has been consequent concern as to the cost effectiveness of applying these treatments as a matter of course, as now often required, this is the first time that a direct measurement procedure which can be used to assess treatments has been demonstrated.
The visualization of water transport through hydrophobic polymer coatings applied to building sandstones by broad line magnetic resonance imaging
Die Sichtbarmachung des Wassertransports durch hydrophobe Polymerbeschichtungen auf Sandsteinen an Gebäuden durch kernmagnetische Breitlinienresonanzbilder
Bohris, A.J. (author) / McDonald, P.J.M. (author) / Mulheron, M. (author)
Journal of Materials Science ; 31 ; 5859-5864
1996
6 Seiten, 10 Bilder, 23 Quellen
Article (Journal)
English
| British Library Online Contents | 1996
| British Library Online Contents | 1995
Building sandstones of Northern Alabama
| Engineering Index Backfile | 1940
| British Library Online Contents | 1998