What chemicals breaks down concrete?
Well water can over time through a process called weathering, other than that acid is excellent, that is how acid rain is effecting us. Also salt and a number of other chemicals and solvents.
Is there any binding material with higher strength than cement for concrete bricks?
Its all are depend upon the condition if there is need than you can use more layer as a binding if there there is no any need then you can use only bricks of concrete.These concrete bricks are very strong for long lasting strength. Although the alternative source is not he long lasting because these things need hard and strong. And if we use less and waste material then there is no need for the changes use it as same position.
What's the strongest concrete, cement, or masonry?
The guy above me is right on the money. Concrete is the strongest and granite, while an expensive aggregate, would be really nice. That being said, you are going to have to reinforce the heck out of this stuff. I've seen it done with fiberglass tape for small castings. If you don't do this, your weights will constantly be chipping, spalling, and cracking under the g's when you put them down. If you truly want the densest material for your weights, I'd recommend Osmium or Iridium. I'd doubt you could lift the weights if you made them out of those materials in the current mold you have and they have to be machined, they can't be cast except under very specialized conditions (very high temperatures, oxygen free atmospheres, etc.). http://en.wikipedia.org/wiki/List_of_ele... http://en.wikipedia.org/wiki/Osmium
How can i build an outside firepit using either brick or stone for large fires?
make a base as big as u want with brick or stone then 1 inch thick layer of sand on the bottom.. then make a wall/box with stone or wall and make sure its all fire proof.. not those cheap things.. then add logs inside.. then fire... WHOOSH!
What are some good alternatives to the conventional plaster (cement+ sand+ water) used for buildings walls which are being used in India?
By plastering, are you refering to martar or grout cement mixture?Motar plastering (that you used to bind the brick, covering surface and decorative work) are more than just cement + sand + water. The main component being a thickening agent which allow you to apply the mixture vertically without them falling apart. In the company I used to work with, we used either pre-gelatinzed active potato flour as some form of cheap alternative to the traditional thickening agent (carbon cellulose of some sort). Tapioca flour also works fine.As for the sand, you just omit them if you don't want some (decorative plastoring required little strenght to function after all)If you 'plastering' actually refer to cement mixture that you use in castin structure - that could be a little tricky. Sand serve the purpose of both enhancing the strenght as well as reducing cost to the final cement mixture. You cement without sand can be weaker (albeit not much), mixing type 1 with type 5 opc can solve that problem (or even make it stronger depend on the percentage of type 5 you included). However, pure cement mixture will be somewhat more expensive than cement+sand (unless your river sand is so expensive that it actually more expensive, in that case go ahead, excluding sand won't going to hurt you so much).As some answer had pointed out, you can also include some pozzolanic (although not to the same percentage of sand). However, in this case you will likely to end up with a mixture for structure casting only. Pozzolanic (especially fly ash) works very well to improve workability (flow) of your mixture, make it very soft and liquid-like, while work best when pouring down, would definitely not stick on your wall.
Is it safe to use M sand instead of river sand in construction of houses?
Although I have only done one set of experiments on sand, i do know when sand is full of silt it takes in moisture and therefor dampens the concrete, it also makes it weaker. From what i have learnt about mining river sand is that the further we mine for this material the more silt and clay is present (as it would) thus making it more difficult for construction company's to get sand of a suitable quality.And so, M (manufactured) sand was founded as a solution.Advantages are; We have been able to create large amounts of sand to a specific quality.It doesn't contain impurities such as silt and clay and therefore it is stronger than riverbed sand.Its helping the environment (we don't have to tear up the landscape)It doesn't contain organic compounds.So therefore i would say; Yes.However there are disadvantages such as workability issues as they are angular/course particles that require more of the other resources that is being used with the sand (increasing costs.) They also have micro fibers which (if produced a certain way) can become too large and affect the strength of concrete.References; http://www.screedscientist.com/t...http://theconstructor.org/buildi...
Whats the difference between thin set mortar and grout?
Mortar is spread thin under the tiles and holds them to the floor. After it is "cured", then you apply the grout in between the tiles to give the floor a smooth even surface.