Boeing

Location: Long Beach, California

Structure: Boeing C-17 Assembly Ramps

Problem

Inhibiting Formation of FOD Concrete Fragments. The concrete assembly ramps are 13 inches thick. Random fine cracks have developed as a result of the loading and unloading of C-17 aircraft taxiing across them over time. The cracks have enlarged, and additional small cracks have propagated from them. These cracks lead to the formation of concrete fragments, foreign object debris (FOD), which can become airborne and have the potential of being sucked into jet engines causing damage.

Solution

The SURTREAT® process involved the surface application of chemical formulations, which penetrate the surface to a minimum depth of 2 inches. The process reacts with the cement phase to increase strength, decrease porosity, and inhibit rebar corrosion along with cement chemical degradation.

SURTREAT® Solutions

• Inhibits salt, water, air and contaminates from penetrating the concrete and forms a better seal in the pores and micro cracks

• Controls pH and maintains the high alkalinity in the concrete and is highly acid resistant

• Migrates to the rebar in liquid and ionic phase and reacts to form a very stable passivating film – more stable than in new concrete

• Converts rust to a stable, inert compound – and increases compressive, flexural, and tensile strength. Also increases hardness and abrasion resistance

Scope of Work

• Perform inspection

• Apply solution

Testing

Concrete strength is determined by measuring the force in kilo Newton’s (kN) required to pull a 2 x 1 inch plug from the concrete surface.  This force is also expressed in the more conventional psi compression strength scale.

The increase in overall strength is very significant in percentage terms and demonstrates how SURTREAT® formulations can increase the surface strength of concrete. It is anticipated that the increase may be even greater in areas along the crack faces, which have become weak and are prime sources of fragments and FOD. SURTREAT® inhibits the formation of FOD by increasing concrete strength.