An Investigation on the Critical Degree of Saturation of Half Brick Samples via the Frost Dilatometry Methodology

Abstract

An Investigation on the Critical Degree of Saturation of Half Brick Samples via the Frost Dilatometry Methodology By Javeriya Hasan Master of Building Science in the Program of Building Science 2019 An assessment of freeze-thaw deterioration of bricks necessitates predicting the moisture content at which frost decay occurs, whereby this is called the critical degree of saturation (Scrit). The study involved performing frost dilatometry testing of eight half-brick samples. Strains along the x, y and z axes of samples were measured, whereby the results show that trends of frost decay were non-uniform along certain axes. However, along the z-axis, brick sample types 305-EB4, 295AF4, 297-EB2 showed Scrit values of 81%, 90% and 77.5% respectively, which were comparable to the slices’ Scrit, which were at 84.4%, 88.1% and 77.5% respectively. Similarly, for brick sample type 349-ER1, the Scrit at its x-axis was 92%, which was near to its slice’s Scrit, at 87.3%. Sample types 60 and 295-F2 showed differences as high as 17% in their Scrit values, at 56% and 88% respectively, compared to their slices, which were at 73.4% and 78.4%.

Investigating the Frost Dilatometry Methodology and Critical Degree of Saturation of Brick Slices Versus Half Brick Samples

“…This study aimed to see how the frost dilatometry methodology could be applied to larger brick samples, as well as see if there is any correlation between the S crit determined from a half brick versus a brick slice. Results showed that strain measurements for half brick samples were non-uniform, as different axes could be seen experiencing expansive and shrinkage strains (Hasan, 2019). Therefore, it was hard to define a clear and reliable S crit for the sample as a whole, when certain axes behave very differently than others.…”

“…Previous research conducted by Mensinga (2009) and Hasan (2019) provides great insight into the use of frost dilatometry to determine the critical degree of saturation for clay brick masonry for varying sized samples. However, each study focuses on a specific size sample and does not explore how different size samples may impact the resulting S crit , when tested following the same methodology within the same laboratory.…”

“…Overall, there are a few key studies that have provided valuable insight into the development of the frost dilatometry methodology. Previous studies conducted by Mensinga (2009), Williams (2014) and Hasan (2019), have all used the methodology of frost dilatometry to provide a better understanding of the critical degree of saturation (S crit ) associated with clay brick masonry. Mensinga (2009), focused on one-dimensional frost dilatometry, which consisted of conducting testing on brick slices.…”

“…More recently Hasan (2019) conducted a study mainly focusing on understanding the critical degree of saturation for half brick samples using the frost dilatometry methodology. This study aimed to see how the frost dilatometry methodology could be applied to larger brick samples, as well as see if there is any correlation between the S crit determined from a half brick versus a brick slice.…”

“…Therefore, it was hard to define a clear and reliable S crit for the sample as a whole, when certain axes behave very differently than others. In addition, when the S crit values for the half brick samples were compared to that of brick slices that originated from the same specimen, values varied by up to 17% (Hasan, 2019). It should be noted that although half brick samples and brick slices were tested from the same original whole brick, these samples were tested in different laboratories by different operators.…”