Carbon Dioxide and Super Glue: How to Make Rapid-Setting Cement
A long time ago, when I was a young chemist, I worked for a small cement company. The owner of the company came up with a process that he said would make rapid hardening cement. He had his chemist (me) make up batches of it and test its properties. It did harden rapidly and we were all happy with the results. We just needed to know how to manufacture it on a larger scale. The owner, who had a degree in chemical engineering, (I think), took over the project and started making large batches in his garage. Since he didn’t have much experience in manufacturing anything, he kept trying to save money by making do with equipment he happened to have on hand. This was all done in his garage which happened to be attached to his house!
One day, after having mixed up another batch of “rapid hardening cement”, he set about pouring it into the containers he had made ready for it. But when he opened the valve on his tank full of “rapid hardening cement” nothing came out of the tank. It had solidified so fast that there was no way it could be pumped out of the tank! He called
I am sure that you have all seen the super-strong glue called Super Glue. I have a few tips and tricks for using it on this site. One of my favorite things to do with Super Glue is to use it to make rapid-setting cement. By rapid, I mean ready to walk on in 5 minutes or less.
The secret to making this fast-setting cement is adding a couple of drops of carbon dioxide (CO2) to the glue before applying it. The CO2 makes it harden almost instantly! You can make your own by using an empty soda pop bottle filled with vinegar and baking soda, as shown below. The reaction of the two produces lots of CO2 gas which collects in the bottle until you open it. This gas is also called Dry Ice, because when you put some in water, it turns into solid ice.
I’m interested in making a rapid hardening cement. My recipe is this: 2 parts plaster of paris and 1 part portland cement. Mix with water to a slurry. Coat the inside of a plastic bag with cooking oil, then pour in the slurry. After 10-15 minutes you have a rigid solid that can be further hardened by soaking in water.
The problem is, this stuff takes too long to set up. I want to develop something that’s at least as fast as two-part epoxy glue, but is much stronger than epoxy when cured and not as corrosive on metal as epoxy is. Also, I want it to be about as cheap as portland cement and plaster of paris. And it has to be made out of readily available materials.
I had an idea that I could improve the rate of setting by adding some CO2 to the mixture as it set up. The idea would be to somehow contain CO2 gas in microbubbles within the cement and have these bubbles gradually dissolve into the liquid cement over time, causing it to set up more quickly since the presence of CO2 causes rapid hardening in portland cements [1]. This would also allow me to add even more water than usual to make
If you’re a homeowner or contractor who needs to make small repairs like anchoring bolts or setting concrete screws, it can be difficult to find the right fast-setting cement. Your plain old Portland cement is too slow. When you need concrete to harden in half an hour instead of three days, you should use rapid hardening cement.
Rapid-Setting Concrete Mix vs. Fast-Setting Concrete Mix
There’s a slight difference between rapid and fast when it comes to concrete mix:
* Rapid Setting Concrete Mix: This is a fast-hardening blend of Portland cement, sand and other materials that can achieve high strength quickly. Some products can even gain 3,500 psi after one hour. It sets in 15 minutes and fully hardens within 24 hours. Use it for applications such as patching roadways, sidewalks and walkways, setting posts that bear weight and making structural repairs.
* Fast Setting Concrete Mix: A special blend of fast-setting cements, sand and gravel designed to set hard in 20–40 minutes. Set fence posts, mailbox posts and lamp posts without mixing or bracing with this product which withstands wind gusts up to 25 mph. It’s also ideal for pouring slabs 2″ thick or more
Growing up in the concrete jungle of New York City, I’ve always been fascinated by the large amount of cement and concrete that makes up our city’s buildings and streets. So when I first heard about rapid-setting cement, which is said to harden in just 10 minutes, I was intrigued. If only we could make our own!
I did a little research and found that while this type of cement is used in a variety of applications (including concrete repair and construction), it is generally only available in large quantities from professional suppliers. It would be great to make some yourself, but most methods require a kiln or similar equipment.
Then I found out that super glue can be used instead. This method requires no special tools, but it’s a little tricky and time-consuming. Here’s how to do it:
You will need:
* Water
* Super glue (cyanoacrylate) or other rapid-hardening adhesive
* Container for mixing (I used an old juice bottle)
* Stir stick or spoon for mixing
So this is the problem with cement. It takes a long time to set and harden. The problem is the calcium silicate hydrate. When water reacts with cement, it forms a gel that binds the aggregate together to create concrete. However, this process takes time as the water has to penetrate through the microstructure of cement paste before it can react with the tricalcium aluminate (C3A). Once it does, it reacts quickly to form C-S-H. This can take anywhere from 2 days to 28 days in warm weather conditions depending on many factors such as curing and temperatures.
In order to speed up this process, other minerals have been used such as calcium chloride or metal sulphates, but these additives are either expensive or cause corrosion in reinforcing steel bars (rebar). So how do we speed up this process?
Well researchers at MIT have found a method that uses carbon dioxide in combination with super glue (cyanate ester) which results in concrete that sets in hours rather than days!
When I was a child, I enjoyed playing with sand and water. On one occasion I added some dirt to the sand in my water table. After mixing it thoroughly, I went to dump it out and discovered that all the mud had hardened and formed a solid lump in the bottom of the container. This was my first encounter with concrete.
Concrete is essentially cement paste – a mixture of aggregate (sand or gravel) and cement which hardens over time. Portland cement is what makes concrete harden; it is made by heating limestone with clay or shale at high temperatures and then grinding the resultant clinker into a fine powder with gypsum. When this powder is mixed with water, any hydroxide groups on the cement react with water to form calcium hydroxide, which begins to crystallize within minutes. Eventually calcium hydroxide turns into calcium silicate hydrate and calcium aluminate hydrate which gives concrete its strength.
One of the problems with using regular portland cement is that it takes several days for concrete to reach its full strength. Engineers are always looking for ways to make concrete harden more quickly so they can get structures built faster, or they can use less reinforcing steel and still be sure that their structures will be safe enough. In order
Anns is a contributor at PanyamCements. We are committed to providing well-researched, accurate, and valuable content to our readers.
