By: Bob Maley, Technical Sales and Service
Over the past 25 years, lining/coating concrete has become more common, particularly in aggressive environments like wastewater applications. Concrete in these environments deteriorates at increasingly rapid rates. Prolonged wastewater detention times and environmental regulations have resulted in elevated H₂S concentrations as influent septicity has risen. Sulfuric acid (H₂SO₄), formed by a series of biological processes, attacks the portland cement paste causing the condition depicted below.
Just as one would be ill-advised to apply high-performance coatings to a densely-pitted steel substrate without first addressing the pits, deteriorated concrete substrates should be similarly treated so that a smooth substrate is achieved. Linings/coatings tend to follow the contour of the substrate resulting in uneven film build and more importantly, holidays/discontinuities within the film. Holidays/discontinuities will cause premature/catastrophic lining failure in immersion service.
If cement paste loss averages ⅜”, which is by no means atypical in aggressive environments, one would need to apply 375 mils of high performance lining/coating just to fill the “valleys,” then apply another 50-100 mils to build the film above the “peaks.” This would require multiple applications, create multiple potential failure planes, and likely create detrimental curing stresses where the film is excessively thick.
A more practical and economic solution would be utilizing an epoxy modified cementitious mortar to restore the concrete substrate back to its original condition. Fashioning a relatively smooth surface for application of the chemical resistant lining/coating is paramount to realizing its design life as a uniform and contiguous film is critical.
Many high-performance coating manufacturers offer such cementitious mortars; however, application characteristics and properties are widely varied. For instance, product X may be difficult to mix, product Y may be difficult to spray, product Z may be difficult to trowel, and so on.
Induron’s Mortarchem provides the best of all worlds…
- All components are conveniently packaged in a five- gallon pail
- Ceramic modification reduces the weight per mixed kit to less than 50% of competitors products
- Homogeneously mixed in less than four (4) minutes
- Effortlessly sprayed
- Effortlessly troweled
- 1-hour pot life @ 70°F
- Remains consistently workable throughout pot life
- Less wasted material
- Excellent film builds on vertical and overhead surfaces
- Excellent adhesion
- Can be recoated with itself in 4 hours @ 70°F
- Can be top coated the following day
- Trowel “licks” and irregularities effortlessly sanding once cured
- Mitigates outgassing
- Competitively priced
All of the above stated Mortarchem qualities translate into less time and effort. Saving time (labor) without sacrificing quality results in reduced job costs, which means greater profits. From an environmental standpoint, it contains zero HAPS (Hazardous Air Pollutants) and 0.01 lbs/gal VOC (Volatile Organic Compounds).
Everyone wins with Mortarchem, the structure, the facility owner, the specifier, the laborers, the applicators, and the contractor. Contact Induron to give Mortarchem a try, and you’ll be more than pleasantly surprised!