sawman

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Five Questions: Breaking the ice

Just don't let anybody use magnesium chloride on your concrete.

How Magnesium Chloride Damages Concrete: One must have a fundamental knowledge of concrete in its hardened state. Concrete, when setting from a plastic to hardened condition, goes through a number of chemical reactions. Basically, hardened concrete consists of two major chemical compounds; calcium-silicate-hydrate and calcium hydroxide. Actually, the reaction products from cement hydration with water are very chemically complex, but for the purposes of this review, we will stick to the basics. When concrete is to be exposed to severe freezing, it is standard practice to entrain a system of microscopic air bubbles in concrete mixtures typically occupying a volume of 5-8%. The purpose of this air-void system is to provide space for the increased volume that water will occupy as it becomes ice. If one were to look at concrete under a microscope in the range of 3000X, this entrained air would look very much like a wasp nest. Magnesium chloride for deicing is effective in reducing the temperature at which water freezes. The problem begins as the magnesium chloride comes into contact with the now deiced concrete surface and remains contained in the melt water, and permeates into the concrete. While deicing salts containing sodium, potassium and calcium are chemically innocuous to concrete, this is not true of magnesium. The magnesium ions accumulate and react with the cementitious compound calcium- silicate-hydrate converting it to magnesium-silicate-hydrate (or a mineral called brucite), which is non-cementitious in nature. In other words, a fundamental major mineralogical product of solidified concrete has now been chemically altered (completely changed). Formation of magnesium-silicatehydrate breaks down the “glue” that binds aggregates together and concrete surfaces begin to deteriorate. The net effect is we now have a chemical and physical attack that concrete is not designed to withstand, nor be subjected to.

January 12, 2011 at 7:32 p.m. ( | suggest removal )

Did you keep your New Year's resolution through the first week?

Where is the "I don't make New Year's resolutions" choice?

January 8, 2011 at 6:13 p.m. ( | suggest removal )

School board listens to patrons at public hearing

Let's also teach them to correctly spell the word "character" and to use apostrophes in contractions.

November 13, 2010 at 11:13 a.m. ( | suggest removal )

Baldwin Bullies

Lose. The word is spelled with one 'o' for crimony sake. Loose-loose conjers up thoughts of diarrhea or the dogs got out the gate. Cows get loose, there are loose women and saggers wear loose fitting pants. You lose money, lose time, and it's a lose-lose situation thinking I won't once again come upon this misspelling of LOSE.

November 8, 2010 at 5:48 p.m. ( | suggest removal )

Baldwin Bullies

Your(citymole) inability to know when to use 'you're' and not 'your'? Say it with me, you are right, you're right, not your right, unless we're talking about your right to be ignorant. It is either possessive or a contraction and it's not hard to determine which to use.

November 8, 2010 at 5:26 p.m. ( | suggest removal )

Terri Lois: Just Bad for the Environment

"as a mater[sic] of fact...your[sic] an idiot"

November 1, 2010 at 11:01 a.m. ( | suggest removal )

Terri Lois: Just Bad for the Environment

Speaking of trash, of the two glossy flyers in the mail today one touted Tony Brown's achievements while Terri Lois' flyer was a negative ad bashing Brown. I guess she doesn't have anything positive to tell us about herself. That's understandable considering she hasn't done much of anything.

What strikes me about the campaigning in this election is all the negative ads which repeatedly mention the opponent's name. Isn't name recognition a big factor in elections? Seems to me they are shooting themselves in the foot by not putting out ads showing themselves in a positive light but instead drilling their opponent's name into people's heads.

October 20, 2010 at 9:19 p.m. ( | suggest removal )

Tony Curtis: A Meeting in the Desert

RIP Tony

September 30, 2010 at 5:58 p.m. ( | suggest removal )

Middle aged men and and their gal durn rock and roll music....

I can't think it was nearly as obnoxious as the thumping bass of hip hop crap that penetrates the walls of our closed up house from over 1000 feet away. Seriously, this has to audible from anywhere in this small town if the officer has a window rolled down.

September 26, 2010 at 11:42 a.m. ( | suggest removal )