The Most Tested Expansion Joints in the Industry

Repairs of Damaged Expansion Joint Materials:

The included pictorial illustrations show a step-by-step rehabilitation of the expansion joint system on a typical parking garage. Also illustrated are a few common occurrences of header material failure (cracking). The illustrations below address the most common issues that cause those problems. Each specific situation requires individual consideration. These illustrations do not address each specific situation, but rather give you a general overview of the process.

This is the typical type of damage done to the joint when the concrete recess corners below have failed.

Figure 1

In Figure 1, there is a small void under the corner of the wing where the concrete recess was not properly filled in with bedding material, leaving a 1/8” void under the wing of the seal. In time as tire traffic impacts and crosses the expansion joint, the constant flexing of the elastomeric material causes a fracture on the top surface.

Figure 2

Figure 2 illustrates either failed patching material at the corners of the joint recess or fractured concrete due to poor compaction. The results are the same as figure one; unsupported or cantilevered elastomeric material bends and cracks from the weight of vehicular traffic.

Figure 3

Figure 3 is the least common found reason for header material failure. Figure three shows an undersized seal being put into place. The edge of the elastomeric header material and wings are cantilevered over the open joint, as wheeled traffic passes over the top of the seal the material bends and cracks. Sizing of the joint seals is an important part of the systems success. Consult EMS for proper seal sizing.

How to Make Repairs At Random Location Repairs

Step One:

In Figure 4, we show the removal of an old expansion joint system in its entirety. The random repair process is scaled down to accommodate specific isolated locations by carefully making multiple longitudinal saw cuts into the header material. The depth of the saw cuts should be approximately 1/2” deep, the width of each cut is approximately 1”. The depth of the cut is critical, damage to the wing of the seal can occur if the cut is too deep or the wing is torn from the body of the seal during elastomeric removal. The multiple cuts are made to remove small portions of material so the integrity of the winged seal is protected. If the wing of the seal is torn from the body of the seal, that portion of the seal must be removed and a new section must be field spliced into place. (SEE FIELD SPLICE PROCEDURE)

After the saw cuts are completed, removal of the elastomeric material should be done with a chisel and hand hammer until all the material is free from the wings of the seal. If entire joint is to be removed is simplified with the use of an air or electric impact chisel.

Figure 5 shows the partially exposed wing of the seal with the material removed from the top of the affected area. At this point you need to determine what caused the damage to the elastomeric header and caused the cracking.

• Lift the wing to look for the obvious empty void under the wing of the seal. (Figure 1)

• Look for broken away or cracked concrete at the edge of the recess. (Figure 2)

• Look for a gaping void where the seal is cantilevered over the edge of the concrete. (Figure 3)

If a broken corner edge is detected, then the affected area must have the joint removed to facilitate proper repairs to the concrete ledge. In some cases the damage may be isolated, in other instances similar to Figure 6, the damage may be too widespread to make localized partial repairs, the entire joint must be removed.

Figure 6

In Figure 6, the recess has been sufficiently cleared of the old failing joint system. All irregularities in the recess and joint stem opening are patched using a suitable patching material. Suitable material is defined as a 100% solids epoxy loaded with sand or Polycrete elastomeric concrete mixes.

The base of the block-out recess must be flat and level across from side to side. Grinding or chipping must correct slab deviation of more than 1/8”. After patching material has fully cured, the entire surface of the recess is to be sandblasted. The sandblasting process removes all laitance and foreign materials from the surface of the concrete in the recess. It also provides the elastomeric concrete with an aggressive anchor profile, which enhances the bond line. It should be noted that there is NO SUBSTITUTE for this process, and other methods have been tried unsuccessfully.

Install the new joint system, see installation procedure. Figure 7 shows a completed product finish.

Figure 7