Marrowbone Crack Repair

Virginia

Tom Brown and Dennis Clute worked directly with Sam West, Project Engineer, to develop the solicitation package including Specs and Drawings for the RCC crack repair on the Marrowbone RCC Structure.

Most of the cracks were typical of cracking on these types of structures. The first step in the process was to identify all of the cracks.

Most cracks need not be repaired, but the sponsors wanted them filled and there was money set aside for the repair.

Tom Brown had made contact with a representative from De Neef Chemicals at a seminar a couple of years ago. It was there that Tom gathered information on the latest technologies for concrete crack repair. Clute and Brown worked with Sam Ware to develop a job specific specification and the documents needed for the solicitation package. Several contractors were solicited; Extreme Technologies got the contract.

The cracks must be cleaned by power washing.

The surface is power washed first.

Holes are then drilled on an angel to ensure that they intersect the crack.

The holes are ported and water is forced into the cracks through the ports.

The water flushes out the crack and provides moisture for the hydrophilic repair product.

The crack filler is poured into five gallon buckets.

The crack filler is a one component product but an accelerator is usually added to accelerate expansion.

The crack filler is pumped into the crack using a professional painter’s pump.

The crack filler doesn’t expand until it comes in contact with water.

The crack has to be wet prior to pumping in the filler.

The crack filler expands as soon as it comes in contact with water.

Expansion of the crack filler ensures intimate contact and good coverage to fully fill the crack.

Quality control is needed to ensure the crack is filled to the specified limits.

The surface of the crack is sealed to prevent ultraviolet light from damaging the crack filler .