Construcion : Hallow Concrete Blocks Vs Bricks

[aamirgillani]

It might be a very off topic for Pak Wheelers here but
Today, I saw an under construction house being built with hallow cemented blocks in stead of normal bricks. I was told that these concrete blocks are manufactured by NLC and one block is used in lieu of 9 bricks. These concrete Blocks are more solid yet cheaper than bricks and keep the ambient temperature of the house low by 35 % of the outside temperature in summers.
How good is this construction material ?

Please share if you have any subject experience or knowledge .

[BackToCivicFaiez]

Its better and worse, both. Some advantages and some disadvantages.

im sure there are more than just one company making concrete blocks.

The disadvantage using concrete blocks is the fact that if the blocks are not made from proper mixture, or water treated/cured properly , they might crack. Where as bricks do not normally crack like that.

Apart from that, since bricks are smaller, you can make more complex shaped structures using bricks even at a smaller scale. But it might not be possible with concrete blocks cuz they are bigger..

Then there is another option as well. Why not just build your entire house out of concrete?
The problem with using bigger building blocks is that if in case it collapses, alot of it collapses together. Where as in smaller blocks, only a part of it collapses.

The advantage of using concrete blocks is that construction is faster as well.

So its entirely upto u if u want to use concrete blocks or bricks...

if u cant understand, just take a sample concrete block and a sample brick. Then try different experiments on it, like hammering etc. That shud reveal to you how much difference in physical properties is there....i think bricks are stronger.

[zia1288]

Concrete's compressive strength is higher than of the brick. So theoretically concrete should be able to bear more load than brick. And yes that's true, concrete doesn't let as much heat transfer as bricks do.

as @ faiez stated concrete should be properly cured else cracks will appear on it.

One thing i'm not sure of is the weight of hollow concrete block. I'm just guessing that it would be heavier than the brick hence it would increase the self load of structure.

I'll get back to this post once I confirm this from my teacher.

[zia1288]

Then there is another option as well. Why not just build your entire house out of concrete?
The problem with using bigger building blocks is that if in case it collapses, alot of it collapses together. Where as in smaller blocks, only a part of it collapses.

Building/constructing entire house out of concrete would make it too costly & heavier too.

There are concrete frame structure buildings around. All the load is carried by concrete ( in form of beams, slabs, columns etc. ) and walls are made of bricks ( but they don't bear any load ) all the load acts on the concrete structures. That is costly, that's the reason residential houses are not built on this method.

[BackToCivicFaiez]

Building/constructing entire house out of concrete would make it too costly & heavier too.

There are concrete frame structure buildings around. All the load is carried by concrete ( in form of beams, slabs, columns etc. ) and walls are made of bricks ( but they don't bear any load ) all the load acts on the concrete structures. That is costly, that's the reason residential houses are not built on this method.

if u use a mix with less cement and more bajri and grinded bricks, it shud be affordable...weight shud be almost same as brick house...

[zia1288]

But that would compromise on the strength of concrete.

[istafa111]

If made properly, concrete blocks are better than bricks. Normally you don't see houses being built using them but they can be seen while constructing buildings. They are stronger and provides insulation.

[mani1]

I believe houses in karachi are built usually with these concrete blocks instead of bricks. A reason which comes up in mind is that concrete blocks do not retain humidity/moisture compared to bricks

[BackToCivicFaiez]

But that would compromise on the strength of concrete.

1800-2500psi should be more than enough for a 2 or 3 story construction....in contrast, the mortar used in walls in brick construction is roughly 5000psi or so but due to more bricks being used, overall strength wud be probably less than half of mortar alone.

I believe houses in karachi are built usually with these concrete blocks instead of bricks. A reason which comes up in mind is that concrete blocks do not retain humidity/moisture compared to bricks

cement is not water proof, it lets water through easily over long period of time.

So both type of construction should leak. But concrete block shud leak earlier due to more cement i think, depending on mix...

in recent times, a few brands of cements have turned out to be 2 number. one of them was bestway. If u cud somehow make sure that good cement is used in the concrete blocks, more people would start using them. Maybe u cud try making ur own blocks...that cud solve the problem.

[memad]

With hollow blocks I think we can not make the structure with load bearing wall design, Other than Karachi I have seen the clay brick use in such designs specially houses. Whereas the Karachi houses have RCC beams below the slab to support the weight at every story.

[aamirgillani]

Please follow the link given below before replying to my post. Thanks

NLC PEARL - Expanding architectural possibilities

[zia1288]

@fazalwahab375 kindly shed some light on hollow concrete blocks/bricks.

[Adeels1]

I am also interested in that topic
So please share your experience
Because i am planning to make a ferma to make my on blocks

Sent from my iPhone using PW Forums

[fazalwahab11375]

The major factor is how good the brick or blocks are manufactured. Both have their advantages and dis advantages. Over the years Hollow blocks have taken over the market, reason being they perform better structurally. Like in US block walls are used as a fill walls. Most of times you need to raise columns to bare loads of roof. In case of seismic activity blocks are better as walls are fill walls only. In case of bricks construction all roof load is uniformly placed on the top of wall mostly in your local construction methodology. But a poorly manufactured blocks can be disaster too. Both blocks and bricks are in compression. a poor concrete mix in block means reduced strength. Also block concrete should be well vibrated and compacted to reduce segregation.

I found this PDF helpful and simple in understanding http://www.ecologicbuild.com/advantages_of_hollow_blocks.pdf

http://www.researchpublish.com/download.php?file=Brick%20Masonry%20and%20Hollow%20Concrete%20Block%20Masonry%20%E2%80%93%20A%20Comparative%20Study-66.pdf&act=book

@fazalwahab375 kindly shed some light on hollow concrete blocks/bricks.

There is nothing called ferma.. the actual word is "Formwork". Also I don't recommend it doing it at your own. As you need vibrating tables as well as low water to cement ratio for the mix. Unless you have proper system. Stay away from DIY.

I am also interested in that topic
So please share your experience
Because i am planning to make a ferma to make my on blocks

Sent from my iPhone using PW Forums