Grout is commonly used as a structural design element in commercial building and construction. Most often, grout is used in flange connections to disperse compressive loads. Early in the adoption of tubular steel pole structures for utility transmission and distribution, it was common for engineers to specify grout for the same reasons in the field. While made for the right reasons, this decision has had problematic consequences for steel poles and towers in the decades following.
Simply put, grout serves its purpose best supporting interior structures. In commercial buildings, flange connections are protected within the building so they’re not exposed to the elements. But on transmission structures, which are exposed to Mother Nature day after day, grout hides and causes some serious structural issues.
Why Grout Removal Is Necessary
Perhaps the most costly consequence of utilizing grout on flange connections is that the grout traps moisture against anchor bolts, since it forms a barrier within the structure. That moisture leads to corrosion that degrades the bolts over time, which can damage the structure so extensively it is at imminent risk of collapse. Since the grout masks this issue, there is no way to know the problem is occurring, unless you’re looking for it.
While most engineers know not to grout new structures, poles and towers last for decades. That means, if you have any existing tubular steel structures with grouted base plates, it’s necessary to remove the grout and perform an anchor bolt inspection to determine the extent of section loss due to corrosion. Depending on what the assessment yields, you can decide on a remediation strategy.
Exo provides expert inspection and repair support for steel poles, lattice towers, and their components, including:
Grout Removal: We can completely remove grout from base plates without taking steel structures out of service.
Corrosion Inspection: We can inspect for and determine wall loss and member loss due to corrosion, so it is repaired or remediated as completely as possible.
Anchor Bolt Repair or Replacement: Deciding whether to repair or replace anchor bolts should be data-driven. We will share detailed insights with you after each inspection to help you make an informed choice.
Don’t leave outdated grout unattended. Work with Exo for safe, total grout removal from every in-service pole and tower.
