Quoting from [mistry_neeta]:can you tell me what chemical solution is added to concrete mixture so that it allows concrete blocks to dry more quickly

There are substances called "water reducers". If you add them to the concrete mix, it gets more "fluid", so you need much less water. Consequently, the block is dry sooner.

Though I guess what you are looking for is something that makes the concrete cure faster. Good fly ash with low LOI and high silica/alumina/iron content sometimes does that, though there are other substances I can't remember right now.

Quoting from [germex]:

If you are in the building industry you should know that filling the blocks with mortar most of the times is nothing but a bad habit... though I have seen architects and civil engineers ordering that.

tisk tisk germex,

The reasoning behind filling blocks is to make a structural element by encasing reinforcement bars in a concrete matrix.

Why submerge rebar in concrete? Several reasons.  Primary is that structurally the tensile strength of the bar can't be predictably transferred to the resulting structure unless encased.  Concrete is literally to alkaline to allow rust, so encasing the bar by filling the voids stops the bar from rusting. Blocks in less developed nations are of unpredictable quality, so if you are an engineer, you state that the voids are filled and discount the block completely an use as your structual value just the "post" created by the void fill.

It only makes sense for applications like light retention walls that have to go up fast. To save time and effort on molding, you use blocks a a "lost molding", fill them with mortar and - voila - you are ready!

The best use of blocks I have seen was here in our desert. A future building only needed the roof to be added. When the architect or engineer saw that the block wall was already bone dry, he ordered to fill the voids with crushed eps (expanded poly styrene) from packaging (like for TV sets, etc.). That's not "the cat's latest meow", but considering the time, money and effort invested, it was about the best I've seen.

Un reinforced block structures should NEVER be used for human habitation. Block walls are too heavy and the connections between blocks too weak to resist comon building streses.  Are you in a earth quake zone??? Does your soil heave when there are moisture changes or freezing? A 60 MPH wind will exert 1 pound per sq foot of lateral stress, on a wall ,got high winds?  If you value the lives of your family i strongly suggest yoiu do not occupy this builing.

Tommy

Quoting from [cyber chap]:


The concrete block ( Hollow block) wall is used to replace brick walls where quick and less aesthetic work is needed. I would like to know our members views on this.

I am going to need just a whole lot more information before I could ever answer this question.

First, in the USA, many concrete blocks have decorative faces that have MANY effects.

Many pecast "blocks" are not blocks at all.

A lot of "blocks" are "bricks".  How close/far to the traditional idea of "brick" does it have to be to be one? Cast died red "blocks" measuring 2 1/2 x  8 X 4 inches, sure LOOKS like a clay brick, but is it one?


If we are talking about a wall with structural characteristics ( supporting something ) hollow blocks generally are superior.


If we are talking a wall that will be exposed to high temperatures, fired bricks are hard to beat as, with anything concrete the cement bond is severely weakened by temperatures over 250 C.


the elaborate answer says about as much about me as it does about your question, I have WAY WAY too much time on my hands.

Quoting from [germex]:

Quoting from [mistry_neeta]:can you tell me what chemical solution is added to concrete mixture so that it allows concrete blocks to dry more quickly

There are substances called "water reducers". If you add them to the concrete mix, it gets more "fluid", so you need much less water. Consequently, the block is dry sooner.

Though I guess what you are looking for is something that makes the concrete cure faster. Good fly ash with low LOI and high silica/alumina/iron content sometimes does that, though there are other substances I can't remember right now.

but if you remember can you please let me know asap thank you

Quoting from [germex]:

Quoting from [mistry_neeta]:can you tell me what chemical solution is added to concrete mixture so that it allows concrete blocks to dry more quickly

There are substances called "water reducers". If you add them to the concrete mix, it gets more "fluid", so you need much less water. Consequently, the block is dry sooner.

Though I guess what you are looking for is something that makes the concrete cure faster. Good fly ash with low LOI and high silica/alumina/iron content sometimes does that, though there are other substances I can't remember right now.

 

thank you would something like cenosphere do the trick

this question has no definitive answer it all depends on geography and the nature of the building. in the uk hollow block cannot be used for domestic dwellings as there is no void between inner and outer skin, moisture will pass through the concrete like a sponge, a cavity must be in place to act both as a moisture barrier and an aid for insulation

The world is more concerned on going green tese days and anything about concrete has its own bad effrect on the environment. I therefore think brick is better than block

Here is to set the record strait.

I lived and worked as a builder in North Queensland for years. Most of the houses are of block construction, because it is strong. Cyclone rated strong. Much stronger than brick. It is also much faster and easier to lay block than brick, though most bricklayers don't know how to lay block. The amount of concrete and steel rio that you put in the blockwork  depends on the building codes for the area in which you live.  Block is not as attractive as brick however it is cheap (diy cheap) and practicle for waterproofing and astetic purposes to seal the walls by bagging them. Gives you a nice rendered finish that looks pretty nice.