This job called for chemical grout injection. Although small in physical size at twelve foot wide and ten feet deep it was a concrete vault in the in the ground in the middle of the campus. We started with drilling injection ports six inch’s on center covering about forty linier feet of vertical crack and installing seventy two ports. The ports and cracks were then injected with water to encourage the maximum travel of the chemical grout and then chemical grout was applied to the ports. Part two was to soak foam rod with chemical grout and stuff it into the two horizontal expansion joints creating the the cover to the vault.with this application completed water was then injected behind the foam rod and on the surface to activate the chemical grout inside the expansion joints creating a new watertight seal in the cracks and expansion joints. There are hard job and complicated jobs but this particular job was extreme in nature. The boilers had been turned off before we could begin, but even with a forced air fan the walls measured a temperature of 120 degrees and the large steam pipes measured 165 degrees. Work was completed in ten minute shifts, with the second man at street level acting as a safety observer and and helper to the man down in the vault. The chemical grout injection was a great success and with the heat results were almost instantaneous. Normally we would have protected the walls from chemical grout spills but the heat was to much for any tape we tried and we had to scrape all the extra material off the walls and the injection ports were removed and grouted back in with concrete mortar.
Written by: Chris Swenson