Thursday 11 October 2018

Reader Response #Draft 3 #Final


This article, The Concrete Advantage, taken from Green Rooftops website, argues that hydrophobic concrete is a better choice for green rooftops as compared to membrane system concrete, which is high cost, unreliable, time wasting and ineffective.

According to the article, one of the tremendous disadvantages of having green rooftops is the membrane system concrete. Membrane system concrete increases the additional construction cost greatly and liability for the collaborators. With the elimination of membranes on the concrete, hydrophobic concrete makes designing, construction, and maintenance processes easier, faster and more manageable. The article also mentions that the perilous element will be eradicated by this hydrophobic technology while benefiting the stakeholders of the green roof. Hydrophobic concrete is durable, highly sustainable and able to detect any cracks and fix it without affecting neighboring plants and medium. 

The article also reports that hydrophobic concrete can remove the need of having the root barrier in green roof construction, where roots will not be able to absorb water from the concrete. However, no Forschungsgesellschaft Landschaftsentwicklung Landschaftsbau (FLL) testing was done to justify and validate the content in the article. 

Overall, with the elimination of membranes on concrete, hydrophobic concrete has more advantages than membrane system concrete in terms of most aspects like time, cost, the life cycle of the concrete, and resources used. Therefore, hydrophobic concrete is a better option compared to membrane system concrete while reaping more benefits in the long run.

Firstly, concrete is one of the most sturdy and durable handmade material. However, when it hardens, the concrete will turn porous and eventually act as a hard sponge, absorbing fluid that seeps through the concrete surface, causing damage to the concrete 's chemical composition and steel reinforcement. To tackle this problem, a trusted company 'Hycrete' has come out a faster and cheaper solution which is to add special crystal admixtures into the standard concrete which react with the water and causes the crystal to grow and block the cracks. In the Article, WATERPROOFING ADMIXTURES FOR CONCRETE, states that  " crystalline products-proprietary active chemicals in a carrier of cement and sand. These are hydrophilic materials that increase the density of calcium silicate hydrate or generate crystalline deposits that block pores to resist water penetration." After the treatment the concrete will be hydrophobic, there it will be better than membrane system concrete.

Secondly, hydrophobic concrete helps to save cost and time.  From the statistic in the Hycrete website, Concrete That Fear Water No More, it states that the cost of membrane concrete and hydrophobic concrete is $6.00 per SF and $3..70 per SF respectively. The cost of hydrophobic concrete will be around 40% cheaper.  The article also mentions that " The approach virtually eliminated the need for waterproofing membrane on the foundation and slab portions of the project, saving up to two weeks of installation time and more than $150, 000 in membrane material cost." By looking at this statement and statistics from the trusted website, it proves that hydrophobic concrete saves a lot more cost and time compared to the membrane system. 

Thirdly, however, the admixture is used to enhance the concrete to increase its durability, workability, and strength, roots still may penetrate through the hydrophobic concrete over time causing water to seep in. Therefore, to repair and maintain the concrete, an injection can be done to the concrete to fix the cracks. For crystal admixture repair, the article states that " Unlike their hydrophobic counter-parts, crystalline systems actually use available water to grow crystal inside concrete. They block water from any direction because the concrete itself becomes the water barrier."  For normal admixture concrete, polyurethane is injected into the cracks and causing it to expand and block the pathway to prevent water from entering. The article also states that "non- flammable hydrophilic polyurethane resin designed to form a flexible gasket or plug joints and cracks in concrete." While membrane system requires to remove and reconstruct the concrete before repairing the cracks. Therefore, hydrophobic will be a better choice as it saves money and time to repair it.

With the above reasons and reliable sources, I can conclude that hydrophobic concrete has better benefits than membrane system concrete in terms of most aspects like time, cost, the life cycle of the concrete, and resources used. Therefore, hydrophobic concrete is a better option compared to membrane system concrete while reaping more benefits in the long run.


References

Green Rooftops. (n.d).  The Concrete Advantage. Retrieved from http://www.greenrooftops.org/advantage.html


Ken, H. (2012, August 13). WATERPROOFING ADMIXTURE FOR CONCRETE. Retrieved from https://www.concreteconstruction.net/how-to/materials/waterproofing-admixtures-for-concrete_o


Hycrete. (n.d). About Integral Waterproofing. Retrieved from https://hycrete.com/products/waterproofing/about-integral-waterproofing/

Barista D. (2007). Concrete That Fears Water No More.  Retrieved from http://hycrete.com/concrete-that-fears-water-no-more/


National Ready Mixed Concrete Association. (2001). Concrete in Practice.  Retrieved from https://www.nrmca.org/aboutconcrete/cips/15p.pdf

Building Trust Sika. (n.d). Waterproofing Injection. Retrieved from https://sgp.sika.com/en/solutions_products/02/02a007/02a007sa01.html


Smart Concrete. (2011, April 5). Understanding The Pros & Cons of Crystalline Waterproofing. Retrieved from https://www.kryton.com/in-the-news/2011/04/05/understanding-the-pros-cons-of-crystalline-waterproofing/


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