Crack Networks and Chemistry in Pyrrhotite-Affected Concrete Extracted from a Massachusetts Site

Published

August 2, 2026

Author(s)

Patrick Dixon, Michael Mengason, David Goodwin, Thomas Russo, Ashley Carey, Osamah Dehwah, Stephanie Watson

Abstract

Homes in areas of Massachusetts are experiencing issues with crumbling foundations due to pyrrhotite, similar to homes in northeastern Connecticut. A basement of a Massachusetts residential home, built in the mid-1990s, experiencing pyrrhotite-driven deterioration, was cored shortly before the foundation was replaced. Here, the analysis of three cores on one wall is described. The cores were subjected to resonant frequency testing, and the dynamic Young's moduli range from 20.0 GPa to 4.5 GPa. These cores were then impregnated with fluorescent epoxy, sliced longitudinally and photographed. Cracks and damage were visible in all core slices. A yellow/green selection was performed on the photographs to segment the damage. To capture the full range of plausible damage areas, a wide range of brightness thresholds was used to construct a simple damage area fraction metric. In the three cores, this metric ranges from 3.5 % to 14.3 % and decreases with increasing dynamic Young's modulus. One core was preliminarily analyzed to estimate the changes in damage over the wall thickness and imaged with micro x-ray fluorescence (µXRF). µXRF appears to show sulfur-rich aggregates and a sulfur-rich local region of cement paste, suggestive of internal sulfate attack, over an analyzed region of a core section. Further imaging of cores with µXRF and data analysis will be performed to estimate the mineralogy of sulfur-rich regions and understand information on element distribution patterns in relation to the cracks and damage.

Proceedings Title

Second International Conference on Iron-Sulfide Reactions in Concrete

Conference Dates

May 12-14, 2026

Conference Location

Mystic, CT, US

Conference Title

2nd International Conference on Iron-Sulfide Reactions in Concrete

Pub Type

Conferences

Download Paper

https://doi.org/10.17605/OSF.IO/7Y4SG

Local Download

Keywords

cracking, dynamic elastic properties, field study, micro x-ray fluorescence, pyrrhotite

Citation

Dixon, P. , Mengason, M. , Goodwin, D. , Russo, T. , Carey, A. , Dehwah, O. and Watson, S. (2026), Crack Networks and Chemistry in Pyrrhotite-Affected Concrete Extracted from a Massachusetts Site, Second International Conference on Iron-Sulfide Reactions in Concrete, Mystic, CT, US, [online], https://doi.org/10.17605/OSF.IO/7Y4SG, https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=961295 (Accessed September 10, 2026)

Additional citation formats