theoretically the strongest concrete

Archimedes Plutonium · 2003-09-15T16:11:26+00:00

From one book on masonry I get a mix for concrete as such:1.6 cement :: 3.2 sand :: 6 gravelFrom another masonry book I get this for concrete mix:5 cement :: 12.5 sand :: 20 aggregate or gravelFor mortar I get this as a mix ratio:1 portland cement :: 1 lime :: 4 to 6 parts sandWhat I am wondering is like a checkerboard or chess board where thewhite squares are each one particle of portlandcement and the blacksquares are each one grain of sand. And that the strongest and ideal mixto make both Concrete and to make Mortar is simple this ratio:1 portland cement to 1 of sandSo that each sand particle is connected to other sand particles by theportland cement between them. Trouble is getting a mix so that it isperfectly mixed as to result in a 3-dimensional perfect packing such asa chessboard is a perfect 2 dimensional packing.Has anyone done experimental tests to see at what ratio ofportlandcement to sand yields the strongest most durable concrete??I would hazard to guess that if uniformly mixed that the 1 to 1 mix isthe strongest.Is there any proof to my above assertion?Archimedes Plutonium, a whole entire Universe is just one big atom where dotsof the electron-dot-cloud are galaxies

Sep 15, 2003 43 Replies

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Brian Quincy Hutchings 22 years ago

I'm still betting that aircrete is stronger than those concretes taht use cement plus filler. but, what is your hypothesis on the "checkerboard" arrangment of the bubbles or rubble, compared to the closest-packing (Kepler) config.? even if you don't believe Hale's proof that it *is* the closest-packing (with the "hexagonal" closest-packing variants; there's another term for them), what possible "better" comes from the rectilinear stacking, which is definetly *not* closest-packed?

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Palaces For The People 22 years ago

There is an entire profession devoted to the meticulous study of cements and concretes. Their publications cost hundreds, even thousands of dollars to equip oneslef with the library of technical specifications of cements and concrete formulas. There are catagories of high-strength and super-high-strength cements and concretes.

The specifications go well beyond the dry ingredients. The quantity of water is critical to the strength, the mixing time has maximum parameters after which the material's strength decreases drastically. Ambient temperatures have an influence, and especially the drying of the concrete is very much a factor in its ultimate strength. And all these things I am saying apply to Portland Cement-based concretes, which itself comes in a variety of types. (You will most likely find type I or II in your home improvement store in 94 pound sacks, but there are other types of Portland Cement.)

The adhesiveness of cement is a chemical property, and influenced by other impurities in the concrete. The dreaded ASR (alkali-silica reaction) is just one of a set of headaches which affect the longevity and structural strength of the concrete. The US patent office is full of clever inventions by people who have figured ways to add strength, or preserve it once it has been had. There are a bunch of patents related just to subject of adding fibers into the concrete to increase the strength.

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Aubrey Hutchison 22 years ago

You have countless variables - your problem is way too simple..

For example: one variable is the strength of the sand. Another is "Strength" what strength are you talking about? Compression Sand mix concrete can have a compression strength of say 6000 psi in one batch and just changing the amount of water makes the mix useless or maybe just usable.

How many brick does it take to build a house is a similar problem?

Aubrey Hutchison PE

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