One of the greatest synergies in modern building history has been Concrete & Structural Steel - the foundation for every city on the planet. The combination of which is truly unlimited. Historically. the greatest threat to this system has been the slow and steady intrusion of detrimental elements (particularly chloride ions) through the protective concrete and harming the reinforcing steel. That damage to the steel then in turn damages the protecting concrete, which in turn speeds up the destruction of the steel - a vicious and expensive process to our nation's infrastructure...
...and from the beginning, we've struggled to find the answers to this detrimental and costly cycle with the addition of nitrites of sodium and calcium. Lower doses were useless and higher doses were unmanagable in the mix with hyper acceleration and losses in compressive & flexural strengths. We've experimented with other materials like long-chain hydrocarbons (alkanes & animal fats mostly) with little to no affect on corrosion and hard-to-handle concrete mixes as well...
ASTM C494 Type S Admixture
...until now. The introduction of an Ultra Low Permeabilty and Shrinkage Reducing admixture (based off the Vapor Lock 20/21 formula) to address the Initiation of steel corrosion. With a migrating (first 1 - 7 hours of fresh, plastic concrete), robust film-forming layer of protection around all ferous material (rebar, p/t tendons, etc.) to drastically inhibit the Propagation phase of steel corrosion - post crack prevention.
The Portland Cement Association has been clear when it comes to steel corrosion in concrete "Corrosion of embedded metals in concrete can be greatly reduced by placing crack-free concrete with low permeability and sufficient concrete cover." If you take care of the proper and sufficent concrete cover - we'll take care of the concrete permeability!
Very possibly the most important chemical concrete admixture advancement since High-Range Water Reducers (Super P's). Vapor Lock 40/40 is the first admixture system to address both phases of steel corrosion in concrete - completely. Two levels of protection that lead to a projected doubling of the lifespan of your concrete structure.
Proper Concrete Cover over Steel....
and an Ultra Low Permeability + Shrinkage Reducing
+ Steel Protecting film concrete.
MasterFormat Involving Vapor Lock 03 00 00 Concrete -
03 30 00 Cast-in-Place Concrete
03 37 00 Specialty Placed Concrete/Shotcrete
03 40 00 Precast Concrete
03 50 00 Cast Decks and Underlayment
03 70 00 Mass Concrete
07 00 00 Thermal and Moisture Protection -
07 10 00 Dampproofing & Waterproofing
See how the industry's 'top' corrosion inhibiting admixtures stack up against each other in the most realistic and advanced chloride corrosion testing to date -
Vapor Lock 40/40 can be budgeted in the fourteen cents ($0.14) a square foot, per inch of concrete thickness, installed, range.
*It's important to note - Vapor Lock is designed and dosed off of cementitious material (cement & fly ash) in your mix. As you move into "structural" concrete mix designs with higher sack contents, the budget of Vapor Lock similiarly increases.