Carolina Foundation Solutions

Cracked Slabs & Concrete- Cracks are very commonly found within concrete materials. Most cracks within concrete are “hairline” or “shrinkage” cracks, which are to be expected and typically do not require repair. The hairline cracks are often 1/16 to 1/8 of an inch in width and exist only in the surface of the concrete. As concrete hardens and cures, the water dries out and causes it to shrink, which creates the shrinkage cracks. This process often spans throughout the first seven years of the life of concrete.

Cracks within concrete which are in need of repairs can vary. Based on the standards of The National Association of Home Builders (NAHB), cracks in interior slabs which exceed 3/16 inch wide are typically in need of repair. Another sign of cracks which may be in need of repairs are when vertical displacement in present. Cracks in areas of the concrete slab which are intended for vinyl flooring, tile floors, or wood flooring often will need to be addressed as well. Cracks which may potentially continue to expand or that have vertical displacement can create tiles to crack, grout to crack, and wood floors to squeak or buckle.

Settled Slabs- Floor slabs most often settle due to poor compaction of the underlying sub-grade; however, dramatic changes in the water table, poor exterior drainage, and ruptured sub-surface piping can also be factors. Carolina Foundation Solutions, LLC offers a variety of solutions to stabilize and, in most cases, lift a floor slab back into place.

Solutions:

Pressure Grouting

Pressure grouting is a process where holes are drilled through the surface of the slab and a very loose cementitious grout mixture is then pumped under pressure to fill voids beneath the concrete. While the grout is still in a liquid form, it creates hydraulic pressure under the slab, potentially causing it to lift upward and back into place. The holes in the concrete are then filled and capped flush with the adjacent concrete surface.

Concrete Slab Piers – The Best Solution for Sinking Slabs

Sometimes slab settlement cannot be corrected by pressure grouting alone. When the sub-grade underneath the slab becomes saturated from leaking pipes or the level of un-compacted fill is very high, the slab can continue to settle even after being pressure grouted. To solve this problem, Carolina Foundation Solutions, LLC offers A.B. Chance helical piers outfitted with a special bracket designed to go through the problem soils and bear the weight of the slab on a permanent anchoring system.

First, a hole must be cored through the slab to accept the helix. Next, the helical pier is advanced through the fill, or saturated zone, and into dry, firm, stable, load bearing soil. Then, a special bracket, designed to support a section of the surrounding slab, is attached to the top of the helical pier shaft and the bracket is used to lift the slab back into place. Finally, the void under the slab is filled with grout and the core holes are patched. For more information about helical piers with slab brackets, visit http://www.abchance.com/accessories/concrete-slab/.

The assembly is used to raise the concrete slab using a screw lift system through the slab. It consists of screw lift slab pile assembly and helical pile. This is a screw lift slab pile cap assembly to be mounted on over a 1-1/4″ square helical pile. The assembly is supplied Hot Dip Galvanized.

NOTE: Standard access hole: 6″-8″ dia for square shaft piles; 10″ dia for round shaft piles. Slab pile assemblies for access holes up to 12″ diameter available as Special Order.

Epoxy Crack Repairs

Carolina Foundation Solutions uses a variety of epoxy compounds to repair cracks within concrete which are in need of repair. The typical repair process consists of cutting the cracks open (using a concrete saw), vacuuming out any dust and loose debris, and then injecting or pouring a 2-part epoxy into the cracks, forming a bond between the separated edges of the concrete.

Stitch-Weld Crack Repairs

Some cracks within concrete slabs are deemed structural cracks. These cracks are repaired using a process commonly referred to as “stitch-weld crack repair”. The process is very similar to that of the standard epoxy repair, but also includes the use of various Fortress Stabilization Systems products. Find out more about the Fortress Stabilization Systems products at http://www.fortressstabilization.com/products.php.

Fig. 1: An existing crack in concrete slab

Fig. 2: Saw-cut crack and areas for staples

Fig. 3: Crack fixed with installed carbon fiber staples and injected epoxy