Sunday, July 26, 2015

What are these building materials

Welcome to our blog, Menfranco general blog
and this post, what are these building materials?
This is how clean washed gravel looks like, anyhow this gravel could be too large to use to make concrete, but the idea is that gravel should be clean, in order to make good concrete

This is how concrete-blend usually looks like, you see concrete blend is gravel and river-sand mixed together. Buy using this type of material you need to add cement and mix it to the right consistency.

What are these building materials?
Dear readers, in our last post we introduced the idea that there are some people that would like to know how to mix cement for their own benefit. Therefore, here we are going to talk about those building materials that the average building bloke could easily use, if he knows how to use them. Now since one of my best knowledge about building materials is about how to mix cement, since I have mixed it by hand and with a mixer hundreds of times, so let us talk about these building materials and how to use them. 
First of all let us see what these materials are and then we will take you through how to mix and use them. Today you can buy these building materials ready to mix, and all you need to do is to add the right amount of water and mix them, but we are not talking about these materials ether, because we want to start everything from scratch:
In building anything with cement there are four main sort of material that we need to recognize well before we start mixing our batches of whatever we want to mix, they are; bricklayers’ loam, plaster sand, river sand and gravel, and of course Portland cement; with these materials you can build just about anything, some of these materials sometimes are called with different names and for different reasons, but that would become a bit hard to explain all of them here, but let us just go over and describe what these material are like:
Bricklayers’ loams is a very fine sand, some of these fine sands could be a tiny bit sticky and when it is wet enough you can almost make a small ball in your hand, but it will always collapse as there is not enough sticky material in it, but if you add the right quantity of cement and water and perhaps something else if required it is easy to lay bricks.
Plaster sand is very fine sand too but not as fine as bricklayer’s loams are, it does not stick together by itself and therefore it would stick together only when you add cement and water to it, this type of sand would be hard to lay bricks with it, but when you have to lay concrete blocks it would be ideal to use this sand provided it is very fine, in this part of the world we call this besser sand.
River sand, or washed river sand is a type of sand coarser or if you want thicker than plaster sand, as the name suggests it comes from the river, in this parts of the world because Brisbane river is salty water it is washed and sieved, but it is possible to find deposit of this sand in some rivers that can be used straight away,  sometimes this sand can be used by itself to lay a top layer on a fresh laid concrete, but its use is mainly indented to mix it with gravels to make concrete.
Gravel or gravels are small stones again these small stones can be found in or near the rivers; in most places if there is proper supplier, gravels are graded so one can order them as they are required, and this is what we need to make good concrete, but at the same time if you happen to be in the middle of nowhere they don’t need to be graded properly to use them for concrete and one could use a mix of different size provided you know what you are doing.
Today of course building people rely more and more from the specialized suppliers, and they order through these suppliers what they need, in fact there are so many things to choose from that it is even hard to know what would be the best thing to use; you see you could even buy bags of ready mixed materials that you can use just by adding water. These materials are very good to use if you have a small job to do, but they would become very expensive to use if you have a large job; I hope you see what I am trying to convey here. 
What we have described above are the main materials required to build most cement things, of course you have to know how to use them, and that is what we are going to write next:

This is a retailer deposit for supply of cement

There are many types cement deposited in this shed, there are ready to mix bags where all you need to to is to add water, but the most important supply for trades people is the plain Portland cement bags that can be used with many different materials

Since there is not enough room to describe the cement properties under the photo above, let us describe it here; cement is like the glue that when mixed with sand, gravels and other aggregates makes these materials stick together. The word “cement” can be traced back to the Romans, who called this “opus caementicum” to describe masonry that resembles concrete. We dare say that the Romans used burned limestone which when you add water turns into hydrated lime and also they used something called pumice that was collected from some part on Vesuvius it was a sort of cement that when you added water would become harder than if you just used lime, this is more or less how I have been told. As you can see there are two main bonding materials that can be used to make concrete and mortar, about this we are going to say a bit more later on.
In this retailer supply shed above there are several sorts of ready to use cement product, so beside bags Portland cement there are bags of hydrated lime, ready bags of concrete blend already mixed with cement, this is very handy if you have to do just a small job, there is read to mix mortar and ready to mix plaster and other things. These ready mixed materials are good, but they become very costly when you have to use a lot of it.
So the cheapest and best way is to mix your own, unless the job is very big, but when the job is big then the best way is to order premixed concrete that is if you have to concrete. If you need mortar or plaster you have to mix your own from scratch, or pay the price of the bagged premixed materials.   

Mixing your own concrete from scratch
Let us start to tell you a story from the beginning about mixing concrete, because sometimes this has really happened to me, as I have been asked a few times the following, from people that had never mixed concrete before:
Here we are asking you to help us, since you know how this is done; you see, we want to mix some concrete to make a small slab, or some foundation for a barbeque or something similar; we have never done this before, so we would like to be explained in a very detailed way how we can do that. We don’t even have a mixer and we want to learn how to do that just using a few tools that we have; we have a couple of shovels and buckets a wooden float and some other small tools. We are a couple of strong blokes and we don’t mind to do some hard physical work, it will be a pleasure to do some useful exercise, so could you help us by telling us how to mix our own concrete. 
Okay, since you don’t mind to work hard, I will be glad to tell you how to go about mixing your concrete by hand, after all I am writing this article because I would like people to know how to do this sort of work; you see we can easily help you mix your own concrete by writing this article, and also you never know if this article could be read one day in a faraway place, where they would like to know how to mix concrete and this article could help them just as it helps you today.  And now, let us assume that you have already the material on site, and that you are ready to mix your concrete.
First of all you need to understand that if you don’t have a mixer, you need a flat platform where you can mix your concrete on, this platform does not need to be made on purpose, all it is needed is a hard surface, perhaps a slab of existing concrete or a concrete path could be helpful or anything at all, as long as this surface is not loose, because you don’t want to mix the soil with your concrete.
 For this time we will assume that for easiness sake the bloke that sold you the building material, has sold and delivered some concrete blend. Now what is concrete blend some of you are wondering; so let us explain, concrete blend is gravel and river sand mixed together approximately two part of gravel and one part river sand, so you don’t have to mix them anymore, it is ready to use.
To make just normal concrete you need to mix by volume six containers of concrete blend to one container of Portland cement, depending on the quality of the concrete blend this may vary a bit, so what we do next; we know that we need a lot of concrete, so we measure say twelve bucket of concrete blend and put that on our platform, then we measure two bucket of cement ready to mix with the blend, you know that you need at least twice as much, but because you are not so sure and your platform is small you prefer to start with a small batch. But wait just a minute before you mix your cement with your blend; make sure that everything is ready, because once you start this process you have to continue until you finish.
Since everything is ready you can spread the cement on the concrete blend, after doing that you take your shovel fill it up and start turning your mixture around, just by pushing the shovel under and turning it over, you need to turn your mixture a couple of time; say first from A to B and then from B to A, so that everything is approximately in the same place, after doing that and you are satisfied that your mixture is more or less even, you can make a hole or well in the middle of it and add a bucket of water, if the water is absorbed quickly, then you know that you have to add more water, if a fair bit of water remains in the centre then you can start folding the outside mixture in the middle, you can add some water as required, but don’t get carried away with adding too much water, because you need to add water bit by bit, you see this is one of those things that you learn as you do it and not before.
You have done all that and now you have a heap of this mixture half mixed; here again you take your shovel and turn your mixture from A to B while sprinkling some water on it, you may need to do this a few times sprinkling water and turning your concrete mixture from B to A and from A to B, you need to do this until you have an even mixture that it is well mixed. Now you have your concrete ready to place wherever you need to place it. I hope that I have been able to describe this procedure clear enough for you to follow easily.
This is how mixing concrete was done in the old days, it was a hard job and it was not as accurate as it is today even if you were an expert at mixing it. Today it is a lot easier with the ready mixed concrete truck that could deliver concrete to your job whenever you need it, and all you have to do is to lay your concrete slab, or whatever you need to do.

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Menfranco general blog, 
What are these building materials
Next time with, The art of mixing cement? 
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