Arshad Raffik
Andrew Jin
Elijah Welsh
Nurul Ahad

Water Repellent Spray for Concrete

Introduction:
Concrete is one of the most durable building materials. It provides superior fire resistance compared with wooden construction and gains strength over time. Structures made of concrete can have a long service life. As of 2006, about 7.5 billion cubic meters of concrete are made each year, which is more than any other artificial material in the world. Concrete is widely used for making architectural structures, foundations, brick/block walls, pavements, bridges/overpasses, highways, runways, parking structures, dams, pools/reservoirs, pipes, footings for gates, fences and poles and even boats. Used in large quantities almost everywhere there is a need for infrastructure, concrete is one of the most frequently used building materials in animal houses and for manure and storage structures in agriculture.

However, cracking is a major problem in construction, usually caused by exposure to water and chemicals. Our innovation, a repellent spray for water and other substances, attacks the problem at the source and has been proven effective in products such as Jason Markk, Reshoevn8r, or Crep Protect, which is ultimately a repellent spray for shoes. Instead of having consumers replace their original concrete with self-healing concrete or even foamed concrete, which is very expensive, they can just use a repellent spray that ultimately prevents cracking on the concrete that they already have. Cement is one of the most widely used materials in construction, but also one of the largest, said to be responsible for around “7 percent of annual global emissions” (Choi, 2016), so why repeat the process all over again, when you can just apply a repellent spray like the one we’ve decided to bring to life.

Other engineering innovations
Concrete plays a vital role in the construction industry. Over the years, increasing demands from the construction industry had led to the birth of various types of concrete and innovations intended to repair concrete. Foamed concrete is one of the variations of lightweight concrete, where it is prone to harmful substances’ penetration, which will disrupt its overall durability and the purpose of usage. As for self-healing concrete, many challenges remain with respect to understanding the self-healing mechanism of bacteria in concrete. Furthermore, concrete is an inhospitable environment for bacteria, so “[e]nsuring the survival of bacteria” (Lee, 2018, February 27) is the biggest challenge facing self-healing concrete. This is because, the survival rate of bacteria after being introduced to concrete still remains unclear to this day.

Also, there are other innovations intended to repair concrete such as Fastpatch Dpr concrete repair kit and Olympic concrete patch. The Fastpatch Dpr concrete repair kit can repair concrete cracks on sidewalks in both, warm and cold weather. The Olympic concrete patch repairs cracked concrete underground and under swimming pools. Although these innovations do a good job at repairing concrete, our product provides a better solution and at a cheaper price. The Fastpatch Dpr concrete repair kit costs $108.50, which is expensive, compared to our water repellent spray which costs $64.95. Our innovation, the water repellent spray for concrete, is designed to prevent the concrete cracking process before it even starts. For example, when our product is sprayed on the concrete it gives it resistance to a variety of substances and repels excess water. This prevents the concrete from starting to crack, thus stopping the problem itself. Furthermore, the other two concrete repair kits can only be used when concrete is cracked. Since our product prevents cracking, there wouldn’t even be a need for concrete repairs.

Technical description of our innovation
Our water repellent spray is a proprietary water-based silane-siloxane water repellent and impregnating sealer for concrete and masonry surfaces. It roughly costs $0.15 to $0.25 per square foot for us to apply the sealer, unless you choose to purchase a gallon of our product for $64.95 and apply it yourself. In most cases, the investment in a sealer is well worth the expense, when you consider that the cost to replace concrete is generally $7 to $8 per square foot. It is easy to apply using simple tools, such as a paint roller of pump-up sprayer, as well as environmentally friendly, in which it provides a breathable type water barrier beneath and to the surface. Chemically, silane and siloxane forms a covalent bond within porous masonry that clots surface pores. Silane and siloxane is known to be “hydrophobic and oleophobic” (Lourenco, 2017), in which they will only wear away if the concrete surface itself wears away.

It provides long lasting protection against deterioration or staining caused by water absorption, salt and freeze-thaw cycles. By chemically, physically and biologically adjusting the magnitude of water repellency, our innovation offers the unique advantage of controlling the longevity of concrete and allowing their “deployment as semi-permeable or impermeable materials” (Lourenco, 2017). With our water repellent spray for concrete we’ve demonstrated that they can be used as covers for concrete and establish chemical compounds that develop high and stable water repellency.

Below is technical information regarding the application and conditions need to be met in order for us to apply our water repellent spray:

Drying Time…………………………………….………..1-2 hours
No Foot Traffic………………………………………………………..12-24 hours
No Wheel Traffic…………………………………………………….24 – 48 hours
Application Temp…………………………………………………….45°F – 85°F
Wet Appearance……………………………………………………….Clear
Dry Appearance………………………………………………………..Invisible
Blush Resistance (Maintaining Glossy Finish)……………..Excellent

The process of the innovation itself
Our water repellent spray for concrete is a novel technology for constructing water-tight barriers to prevent the cracking of concrete. It penetrates and chemically bonds deep within the substrate to form a hydrophobic barrier (hydrophobic literally means “the fear of water”) within the pores, allowing the surface to repel water and other substances. Once sealed, substrate become less susceptible to cracking, spalling, pitting, staining, mold, mildew, algae and efflorescence. Our innovation is a great water repellent sealer for concrete driveways, paver patios, stamped concrete pool decks, garage and warehouse floors, basement floors, brick homes and more. Also, it is resistant to freeze-thaw cycles, de-icing salts, mold, mildew, fungus and efflorescence, in which water and other substances will bead off sealed concrete, brick, stone, pavers and other masonry. Our ready to apply, 1 gal. container covers up to 175-250 sq. ft. in 1 coat. Even after the glossy finish goes away, the sealer will continue to work in the pores for up to 7-10 years. In addition, our innovation can be used to seal concrete driveways, brick chimneys, paver patios, stone walls, pool decks, and more.

The average coverage rate is 250 ft2/gallon in one coat. Coverage rates will vary depending upon surface porosity and texture, and application method. The cost for the chemicals siloxane and silane in total will cost approximately $15-$20 per kilogram each. The cost for the gallon containers we would be using to package our product is approximately $2.50 per container. It roughly costs $0.15 to $0.25 per square foot for us to apply the sealer, and we would market. We will hire three chemists in order to successful produce the silane and siloxane mixture. In addition, we would hire a few labor workers, in which their job is to carefully place the mixture inside the container to seal it, label it, and package it off. The chemists we hire will get paid $82,610 a year and the extra labor workers would get a year salary of $35,669. It would take approximately 3 days in total to have our product ready for delivery, as it will take one to two days for the silane-siloxane mixture to be produced, and the last day for packaging and labeling in our gallon shaped container made from plastic. Using this mixture on concrete will prevent the cracking process, until the concrete surface itself wears off.

Conclusion:
Concrete and cementitious construction materials are essential construction materials for buildings, civil engineering, and general construction in modern society, and it is deemed that the development of construction materials that can completely substitute for concrete is very problematic, even in the future. Although concrete is one of the most widely used construction materials, it is characterized by substantially low tensile strength in comparison to its compression strength, and the occurrence of cracks is unavoidable. In addition, cracks progress due to environmental conditions including damage by freezing, neutralization, and salt, etc. As a result, increasing demands from the construction industry had led to the birth of various types of concrete, such as foamed concrete and self-healing concrete, to prevent excessive cracking. These innovations ultimately support our water-based silane-siloxane water repellent, as foamed concrete’s physical properties improved in terms of absorption when introduced to a water repellent and the uncertainty still surrounding the survival of bacteria in self-healing concrete.

References
Lee, Y. S., & Park, W. (2018, February 27). Current challenges and future directions for bacterial self-healing concrete. Retrieved from https://link-springer-com.ccny-proxy1.libr.ccny.cuny.edu/article/10.1007/s00253-018-8830-y
Choi, H., Inoue, M., Kwon, S., Choi, H., & Lim, M. (2016, March 30). Effective Crack Control of Concrete by Self-Healing of Cementitious Composites Using Synthetic Fiber. Retrieved from https://www.mdpi.com/1996-1944/9/4/248
Lee, Y. L., Hoe, C., Lim, M. H., & Lee, F. W. (2018, November 26). Engineering Properties of Foamed Concrete Containing Water Repellent. Retrieved from https://www.e3s-conferences.org/articles/e3sconf/abs/2018/40/e3sconf_iccee2018_02005/e3sconf_iccee2018_02005.html
Lourenco, S., Saulick, Y., Zheng, S., Kang, H., Liu, D., & Lin, H. (2017, April 01). Engineering water repellency in granular materials for ground applications. Retrieved from http://adsabs.harvard.edu/abs/2017EGUGA..19.2512L