The George Bush Intercontinental Airport opened in 1969 and has undergone numerous expansions since. When a groundwater infiltration in the Inter-Terminal Train (ITT) underground tunnel was noticed, immediate repairs were needed. The ITT is a passenger train service connecting all airport terminals and a hotel. The Houston Airport System would only have a limited amount of time each night to shut down the ITT to conduct the repairs. So, they needed a solution that could be applied to the negative side (inside) of the tunnel and could also be effectively applied in short windows of time.
The repair team chose the Krystol Leak Repair System and Krystol T1 to provide blind side integral Krystol crystalline waterproofing, to address the most severe cracks and leaks that were posing a significant structural threat to the tunnel. The Krystol T1 product was chosen for its ability to penetrate concrete walls and stop water under hydrostatic pressure. It met the US Army Corps of Engineers standards in the project specification especially referencing its ability to reduce the permeability and increase the chemical resistance of concrete.
The repair team first chiselled a chase/keyway at the leaking cracks and applied the fast-setting Krystol Plug, which halted leaks immediately and then they applied Krystol Repair Grout over the plug to permanently stop the water. Then the team applied Krystol T1 over the leak repair and to the concrete walls to protect against future water intrusion. Both Krystol Repair Grout and Krystol T1 contain Krystol® Technology, which chemically reacts with water and un-hydrated cement particles to form insoluble needle-shaped crystals that fill capillary pores and micro-cracks in the concrete and block the pathways for water and waterborne contaminants. A unique feature of the Krystol Technology is its ability to lie dormant indefinitely within the concrete. If a new crack should form in the concrete and water begins to penetrate, it will react to seal the leaking location, giving the repair and the concrete a self-healing ability.
As part of the Krystol Leak Repair System, Krystol Repair Grout is a crystalline concrete waterproofing product that stops the flow of water to permanently repair leaking cracks, holes and joints in concrete, and can also be used to resurface and waterproof defective, damaged or deteriorating concrete. The grout employs advanced fiber technology and shrinkage controlling additives to prevent cracking.