Humidity Testing of Support Columns

Summer Consultants provided consulting services on a very urgent and necessary issue at an office building on a campus in the Metropolitan Washington DC region. The building is newly renovated, and consists primarily of offices, conferences, break rooms. Despite this renovation, in the basement boiler room,  cracks were visible along each side of multiple concrete columns, and it became clear that the columns were approaching failure.

Structurally speaking, the building was designed such that should one column fail, the building as a whole would be susceptible to progressive collapse. In order to prolong the life of the failing columns and allow time for consultation on how to modify the existing building systems to create space to repair the columns, a steel structure was installed around each of the failing columns.

As part of the project, I was given the opportunity to escort the contractor to perform humidity testing on four different columns. I was able to gain an understanding of how this testing was conducted and witness the actual testing firsthand. The contactor began by drilling a small hole in the concrete column. The depth of the hole was approximately 20% of the column depth, in this case, about 3.2-inches. Once the hole was drilled, a Wagner RAPID RH probe was set into the column and covered with tape to prevent any additional moisture or debris from entering the column. After 24 hours, we returned to the site, and the relative humidity percentage was recorded at each column . The hole was then patched with grout.

This was an interesting process to watch, as coordination with the contractor was important to understand as a consulting engineer on a project of this nature. It was beneficial for me, as a young engineer, to see a new type of concrete testing, and will likely be useful for me moving forward should column failure become an issue in any future project.