Compaction Grouting (Compaction Grout Columns)

Compaction grouting, also known as low mobility grouting, is a ground improvement technique that reinforces unsuitable soils in-place and is used to remediate sinking structures or to underpin existing foundations. Compaction grouting can be performed with only 6 feet of overhead space. The process of compaction grouting involves advancing small-diameter temporary steel casing to a predetermined design depth and then pumping a stiff (low mobility, low slump) grout in controlled lifts at high pressure as the casing is gradually withdrawn. This process displaces and compacts the surrounding soil and builds high-stiffness compaction grout columns. The stiff columns, combined with the improved surrounding soils, act together to support the structure. The grouting material is mixed on-site with a mobile mixer and is injected in a controlled manner to predetermined volume, pressure or movement criteria. In some instances, compaction grout columns can be used to jack up existing structures that have undergone settlement.

Jet Grouting (Jet Grout Columns)

Jet grouting is a ground improvement technique that improves unsuitable soils in-place and is used for underpinning existing foundations, constructing earth support walls, and constructing groundwater cutoff walls. The process of jet grouting involves advancing steel drill rods using a high-pressure bottom discharge water/grout jet, stopping the bottom-discharge once the predetermined design depth is reached, and then engaging a high pressure side-discharge grout jet that erodes and mixes the soil as the drill rod string is slowly rotated and gradually withdrawn. This process creates “soilcrete” jet grout columns with increased strength and reduced permeability.

Void Grouting

Void Grouting can be used to fill unwanted voids, such as below slabs-on-grade or within abandoned pipes and tunnels.  Our tailored grout mixes, combined with our mobile grout mixing and pumping equipment, allow us to develop project-specific void grouting solutions using neat cement, cellular concrete, low-mobility or chemical grouts.

Slab Raising (Mudjacking)

Slab raising, also known as mudjacking, is used to help repair existing slabs that have undergone settlement due to underlying unsuitable soils. Slab raising involves coring a series of localized holes in the slab and pumping grout under pressure until the slab returns to its original level.  In many cases, the repaired slab functions with minimal to no future settlement. However, since slab raising only addresses the resulting symptom (i.e. slab settlement) and does not correct the underlying unsuitable soils, there is the risk that the soil and slab could settle again over time. If needed, ground improvement methods such as Compaction Grouting can be considered as a permanent solution to directly address the unsuitable soils.

Slab Curl Repair

Slab curl repair is a type of Void Grouting.  Slab curl occurs when the top and bottom surfaces of concrete slabs cure differently, causing the slabs to flex and cure in a concave shape at the control joints.  This “curling” results in uneven slab contact with the underlying soil or base material, ultimately leading to deterioration and cracking of the slab under everyday service loading. The grouting process for slab curl repair involves coring a series of localized holes along the control joints and pumping grout to fill the void below the curled portion of the slab. After the grouting process is complete, owners sometimes choose to grind down the curled portion of the slab to restore an even floor surface.

Lightweight Cellular Grouting (Cellular Concrete)

Lightweight cellular grouting is a process that involves mixing cement, water and closed-cell air bubbles. The grout can be modified to accommodate a variety of applications including mass lightweight filling, soil stabilization, pipe abandonment and Annular Space Grouting.

Annular Space Grouting

Annular Space Grouting is a type of Void Grouting that consists of filling the annular space between an inner “host” pipe and an outer “liner” pipe in cases where the host pipe has deteriorated and requires repair/lining.  The grouting process requires access at each end of the pipe or access at regular intervals for relatively long pipe alignments.  Grouting is normally performed from the lower end of the pipe with neat cement or cellular concrete grout being pumped “uphill”.