My other sites; http://frankmenchise.com,http://diybrickwork.com,http://manneedsgod.co.uk
Anyhow, you can also see more at this addresses, DIY brickwork
and, http://diybrickwork.com, To see more, Mix your own cement
Learn the
art of mixing cement, part two
Learn to recognize and use the building materials when we
mix cement;
In our previous post, we have written what are the building materials, and
we have explained how to mix concrete by hand, this procedure can be applied to
mix mortar and plaster etc. We have also explained how you can recognize the
raw building materials.
Having done that, now let us imagine that you need concrete, you live in
the middle of nowhere and you have only a few tools, but you now a faraway
place where you can go and buy Portland cement; you are not going to buy
anything else at that place, because it is too far, it will be costly to bring
it in, so, the rest of the concrete materials you are going to find near the
river banks. I know it is like going back in time a hundred years ago, but
there are parts of the world that are still that far back. Therefore, learning
how to recognize the basic building materials for making concrete, and then
mixing concrete by hand can still be useful today. So, we are writing these
articles, hoping we can help any do it yourself small owner builders.
Now, we have to add that what we are writing here is how we
have done these things, and we know they work, however, it is only our view and
they work well in all minor jobs, but if you have large important jobs, you must
consult the local experts.
Now let us see how we mix concrete with a mixer.
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Mixing
concrete with a mixer
Okay, let us make this clear, there may be
several ways how to mix you concrete; you can mix it on the ground, as we have described
above, you can mix concrete in a wheelbarrow, if you have a wheelbarrow with a
good tray, or you can mix it with a mixer which is helpful to have. But what
are the different procedures when you mix, in order to achieve the best result
with the least amount of time and work:
The greatest difference for mixing concrete
and also other cement materials is mainly this: when you mix by hand you can
achieve the best result by mixing the materials with the cement before you add
water, as this helps to make a more even mixture quicker: But when you use the
mixer you don’t need to do that, in fact, you can have better and quicker
result, by following this procedure hereunder:
Start the mixer and put in the mixer some
water, approximately the proper amount to mix the whole batch, you know how
much water to use once you have made a few batches.
Now before we proceed to mix, let us talk
about the water amount. On building sites, it is near impossible to tell you
how much water you need exactly, due to the fact that the materials you are
using contains an unknown quantity of water, therefore, the quantity of water
varies, you see, the wetter the materials are, the less water you need and vice
versa if they are dry.
Now, let us assume that because you are new
at doing this job, you are using a dry small bucket to measure the quantities
of the building materials; in this case you have gravel and river sand in
separate heaps, you know that this concrete is going to be mixed 6 to 1, but
overall this batch you are going to mix 8 small buckets of gravel four of river
sand and two of Portland cement:
Now the quantities above is how the best and
strongest cement can be achieved, with a minimum of Portland cement used; very
likely these quantities are written in the specifications, if you have any
specification written, and the ready mix people use those amounts and have a
perfect concrete, because the concrete mixer will mix it well and as dry as
possible. But by experience on building sites, we use a bit more river sand and
a bit less gravel, as this makes it easier to work with overall.
Now let us go back to mix our concrete:
So, after you have poured the water into the
mixer, you put one single bucket of gravel and while the mixer turns put the
two small bucket of cement into the mixer, the cement in the mixer will
immediately mix in the water and the first bucket of gravel will make sure that
it does not stick to the mixer, because it will cut though any lumps easily,
now you add four buckets of river sand, and this again will mix very quickly
and become like a thick cream, all you have to do next is to add the other
seven bucket of gravel, once you have done that you only need to wait a little
bit for the mixer to mix it properly and your concrete is ready. Now all you must
do is to tip your concrete in a wheelbarrow and take it to the place you need
to concrete.
This is the quickest and best way to mix
concrete in a mixer, as I have done it for thousands of times, but I need to
say that on building sites, where there is plenty of cement to mix and the
workers have to try not to injury themselves, by lifting hundreds of bucket
full of material all day long, they use to measure the materials by the
shovelful, but you have to be an expert at doing that to get everything
measured right. I hope this description of how to mix concrete is clear enough.
Before we leave this concrete discussions we
want to add more information; you see, concrete in itself is very strong in
compression, but is lacks strength under tension, so, to make concrete very
strong and last a very long time you need to use steel in the concrete; here is
a link that will help to understand some of these issues.
How to
Make Concrete Even Stronger: 6 Steps
(with Pictures)
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Mixing mortar, plaster, or cement topping.
Now that we have described how to mix
concrete by hand and by using a mixer, the same ways can be used to mix mortar
and/or hard plaster or cement topping etc. So now, we do not need to explain
step by step how to mix them, but we will describe only the different amount of
things that are used; but try to remember that when you mix by hand, it is a
lot easier to mix the dry materials first and then add water, but when you use
the mixer it usually is better and quicker to start with the water first.
To mix mortar for the bricklayer;
Just by using brickies loam and Portland
cement, this mixture by volume is most likely 4 part brickies loam to one part
Portland cement, but it could vary from (3 to 1) to (6 to 1) the aim here is to
give the bricklayers what is easy to work with, and at the same time you don’t
want to make the mortar a lot stronger than the bricks when it dries, and you don’t
want to make it too weak for the job you are doing, so, it makes sense to see
what the bricklayer reckons is good enough for the job; sometimes when making
mortar you can replace part of the Portland cement with hydrated lime, plus
other things to make the mortar easy to work with.
Mortar for cement blocks
The mortar for cement block is usually three
parts fine plaster sand and one-part cement, it is a bit different from the brickie’s
loam, as it is thicker and stronger and very close to the block’s colors when
dry.
To mix cement plaster to plaster walls;
This mixture is usually 3 part plaster sand
and 1 part Portland cement, in some countries where lime is easier to have than
cement it can be made by using a mixture of lime and cement for the interior,
we believe that there are a lot of old places that they have used lime only,
the cement mixture is used wherever it is too wet.
Cement topping;
This mixture is usually 3 parts river sand to
1 part Portland cement; it can be used straight on the cement if it is still
green, but when the cement is dry you need to make sure it is clean and rough
for the cement to bond, you may have to use tools to indent the existing
concrete, then you have to wet the cement and also you may need to use some
cement bounding agent and/or paint to concrete with this cement glue called Weldbond
or Bondcrete or whatever and place the
topping cement according to the instruction supplied, if these concrete glues
are not available, you have to wet the concrete that you have to lay the
topping on, then make some slur of water and cement and somehow work it in with
a brush as if you paint the concrete, and before this starts drying lay your
topping on it.
These three mixtures plus the concrete are
the main things that are required when we build with cement, of course, for
those people that do not know how the different materials look like, is still
hard to understand the hole procedure, but if they read a few times what we
have said, they should have a fair idea of what we are talking about. Anyhow, I
have described several things already, but I think that I need to describe how
to mix mortar with lime only, as it was done in the old days and here I am not
talking just hydrated lime that you can buy at the hardware store, but I am
talking about quick-lime as it comes from the kiln and how we made slacked lime.
So, see you in our next blog, lime use in building, part three.
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