J.F. Brennan Co. Inc.  - 820 Bainbridge Street - La Crosse, WI 54603 - Phone: 608/784-7173 - Fax: 608/785-2090

Concrete Repairs – Preplaced Aggregate Concrete (PAC)

Preplaced Aggregate Concrete (PAC) placement has been used on thousands of bridge, dam and other structures since the 1970s.  After the deteriorated concrete is removed from the structure, the contractor erects water tight forms and places clean, graded aggregate into the form.  The aggregate is normally sluiced into the form using pumping systems and hoses.  The grout is then pumped into the forms to fill the voids within the aggregate mass.  The non-shrink, cement/fly ash based grout is formulated to not only fill the voids in the aggregate but also to flow into the micro-fissures in the original concrete or masonry structure.

Markets Served:

Casinos, Government Agencies and Municipalities, Harbors, Industrial, Pulp & Paper Mills, Railroads, Utility Companies.

Advantages:

1. High bondability and low shrinkage –  70 to 90%

2. PAC can be placed above or below the water without                 the need to dewater

3. Point to point aggregate contact yields increase                       strength

4. No cracking as grout mix allows complete hydration of              the cement by pozzolanic activity.

5. Ideal for remote locations as aggregate and grout both               can be pumped long distances without the need for                   concrete trucks immediately adjacent to job site.

Disadvantages:

1. Depending on site location, costs may be slightly                     higher for initial repairs but repairs should be more                     durable than cast-in-place repairs

2. Engineering firms are not always aware of the PAC                   process

Experience:

Hydro Dam Piers

Bridge Piers

Spillways

Abutment Walls

Tunnels