Applying chemical analysis gained from taking a chemistry class, the author reflects on his summer employment at a chemical plant where he tested the effect of tartaric acid had on one of the company\u27s products, Redline Speed Crete

James, Reuben

English

Scholarship at Parkland

Parkland CollegeA with Honors Projects Honors Program2013Effects of Retarder on CementReuben JamesParkland CollegeOpen access to this Article is brought to you by Parkland College's institutional repository, SPARK: Scholarship at Parkland. For more information,please contact spark@parkland.edu.Recommended CitationJames, Reuben, "Effects of Retarder on Cement" (2013). A with Honors Projects. 100.http://spark.parkland.edu/ah/100 Reuben James Chem 101-004 Honors Project Fall 2013  The summer before I started continuing my education at Parkland I worked for Euclid Chemical of Kirkland, IL. I worked mainly in the lab as a quality control technician. At Euclid, we made hydraulic cements, paints, and epoxies. I performed different tests on these products to see if they met certain standards. These tests included color correction, tensile strength, compression, elasticity, and set times. Besides checking the products for the normal conditions, I was sometimes asked to perform tests to see what alterations resulted. One such test I performed was adding retarder to our normal Red Line Speed Crete.  The Red Line Speed Crete is a cement meant to patch. Cement is an ingredient of concrete. The main difference between cement and concrete is that cement doesn't have any aggregates, such as rocks, in it. Cement works by going from a dehydrated powder form to a hardened form in the shape of whatever mold it was put into or on. It does this because of the 2Ca3SiO5 (C3A) in the cement being hydrated by water to form a gel that hardens. This hydrating process is written:  2Ca3SiO5 + 7H20 → 3(CaO)*2(Si02)*4H20 (gel) + 3Ca(OH)2.  This cures by the two products combining to make a solid hardened product. (Concrete,Wikiedia)  I performed tests on our Red Line. In these tests I added different amounts of tartaric acid (C4H606) (Tartaric, Wikipedia) retarder to a normal batch of the Red Line, to see what changes took place. The reason the company had me perform these test was because we were looking for the set time to decrease so that the product could be used in hotter climates, due to heat speeding up the curing process. The Texas department of transportation had problems because the heat made the concrete harden faster so they asked us to make it so they have more time to work with the Red Line. I tested initial set time to check for workability, final set  time to see the overall curing time, and I used a pneumatic crusher to see how much force the hardened cement could withstand. After running different tests, there was a general trend in the results. The more retarder that was added, the slower the set time and the weaker the concrete became.  Due to chemistry I now have more knowledge as to why the set time was slowed down based on the chemical properties. The first reason the retarder slows down the set time is because it draws the water to it, keeping it away from the cement by forming a type of diffusion barrier. This slows down the overall reaction giving it more time to work with. This also provides for the adverse effect of weakening the final state of the cement because the water wasn't able to fully react with the C3A making the normal rigidity it produces lessen. Another reason retarder slowed down the set times pertains to the Ca(OH)2 ions that are formed. The retarder is an organic substance and this makes the hydroxide very attracted to it. This forms organic hydroxyl ions that have a very high saturation point. These new ions now suck up the water that is meant for the C3A. This slows down the curing time on the cement as well as giving you a longer working time with it. (Khan, 64-65)  In conclusion, due to my professor asking me to participate in this honors project, I furthered my understanding of key chemistry concepts. I was able to reflect on a past experience and further my understanding of the situation. I am now more knowledgeable about the effects retarder has on cement.   Works Cited  • "Concrete." Wikipedia. Wikimedia Foundation, 18 Nov. 2013. Web. 18 Nov. 2013. <http://en.wikipedia.org/wiki/Concrete>.  • Khan, Bazid and Muhammad Ullah "Effect of a Retarding Admixture on the Setting Time of Cement Paste in Hot Weather." JKAU: Eng. Sci. Vol. 15 no. 1 (2004):pg.63-66.  • "Tartaric Acid." Wikipedia. Wikimedia Foundation, 19 Nov. 2013. Web. 25 Nov. 2013. <http://en.wikipedia.org/wikifTartaric_acid>.  

Effects of Retarder on Cement

SPARK: Scholarship at Parkland | Parkland College

Parkland College
A with Honors Projects Honors Program
2013
Effects of Retarder on Cement
Reuben James
Parkland College
Open access to this Article is brought to you by Parkland College's institutional repository, SPARK: Scholarship at Parkland. For more information,
please contact spark@parkland.edu.
Recommended Citation
James, Reuben, "Effects of Retarder on Cement" (2013). A with Honors Projects. 100.
http://spark.parkland.edu/ah/100
 Reuben James 
Chem 101-004 
Honors Project 
Fall 2013  
The summer before I started continuing my education at Parkland I worked for Euclid Chemical of 
Kirkland, IL. I worked mainly in the lab as a quality control technician. At Euclid, we made hydraulic cements, 
paints, and epoxies. I performed different tests on these products to see if they met certain standards. These 
tests included color correction, tensile strength, compression, elasticity, and set times. Besides checking the 
products for the normal conditions, I was sometimes asked to perform tests to see what alterations resulted. 
One such test I performed was adding retarder to our normal Red Line Speed Crete.  
The Red Line Speed Crete is a cement meant to patch. Cement is an ingredient of concrete. The main 
difference between cement and concrete is that cement doesn't have any aggregates, such as rocks, in it. 
Cement works by going from a dehydrated powder form to a hardened form in the shape of whatever mold it 
was put into or on. It does this because of the 2Ca3SiO5 (C3A) in the cement being hydrated by water to form a 
gel that hardens. This hydrating process is written:  
2Ca3SiO5 + 7H20 → 3(CaO)*2(Si02)*4H20 (gel) + 3Ca(OH)2.  
This cures by the two products combining to make a solid hardened product. (Concrete,Wikiedia)  
I performed tests on our Red Line. In these tests I added different amounts of tartaric acid (C4H606) 
(Tartaric, Wikipedia) retarder to a normal batch of the Red Line, to see what changes took place. The reason 
the company had me perform these test was because we were looking for the set time to decrease so that the 
product could be used in hotter climates, due to heat speeding up the curing process. The Texas department 
of transportation had problems because the heat made the concrete harden faster so they asked us to make 
it so they have more time to work with the Red Line. I tested initial set time to check for workability, final set 
 time to see the overall curing time, and I used a pneumatic crusher to see how much force the hardened 
cement could withstand. After running different tests, there was a general trend in the results. The more 
retarder that was added, the slower the set time and the weaker the concrete became.  
Due to chemistry I now have more knowledge as to why the set time was slowed down based on the 
chemical properties. The first reason the retarder slows down the set time is because it draws the water to it, 
keeping it away from the cement by forming a type of diffusion barrier. This slows down the overall reaction 
giving it more time to work with. This also provides for the adverse effect of weakening the final state of the 
cement because the water wasn't able to fully react with the C3A making the normal rigidity it produces lessen. 
Another reason retarder slowed down the set times pertains to the Ca(OH)2 ions that are formed. The retarder 
is an organic substance and this makes the hydroxide very attracted to it. This forms organic hydroxyl ions that 
have a very high saturation point. These new ions now suck up the water that is meant for the C3A. This slows 
down the curing time on the cement as well as giving you a longer working time with it. (Khan, 64-65)  
In conclusion, due to my professor asking me to participate in this honors project, I furthered my 
understanding of key chemistry concepts. I was able to reflect on a past experience and further my 
understanding of the situation. I am now more knowledgeable about the effects retarder has on cement.  
 Works Cited  
• "Concrete." Wikipedia. Wikimedia Foundation, 18 Nov. 2013. Web. 18 Nov. 2013. 
<http://en.wikipedia.org/wiki/Concrete>.  
• Khan, Bazid and Muhammad Ullah "Effect of a Retarding Admixture on the Setting Time of 
Cement Paste in Hot Weather." JKAU: Eng. Sci. Vol. 15 no. 1 (2004):pg.63-66.  
• "Tartaric Acid." Wikipedia. Wikimedia Foundation, 19 Nov. 2013. Web. 25 Nov. 2013. 
<http://en.wikipedia.org/wikifTartaric_acid>.  


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