It also fails to mention any study on creep and relaxation.
When concrete fails the cement matrix crushes and the aggregate shears and crushes.
I doubt such a flexible concrete would be used for a structure for uses such as an office building. Flexing under load may be within the limits of this concrete, but it isn't very comfortable.
The cracking is due to the ice entering cracks and freezing, thawing, and freezing again in the larger and propogated cracks.
To ensure good freeze-thaw strength, air entrainment is used to allow the ice to expand.
Cracked concrete is not always a bad thing! Concrete forms, when designed correctly, take into account cracking over its servicable life. When you are driving, look at the bridges you go under, there are cracks and chunks of concrete missing.
This is not unsafe. The concrete at the top of the beam is in compression (which we want), and at the bottom the concrete is in tension (which is a bad thing). BUT, that concrete in tension is only used as a cover to prevent rebar from rusting. Removing chunks of that tension concrete is not decreasing the overall strenght of the beam, as long as the steel rebar is not exposed.
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It also fails to mention any study on creep and relaxation. When concrete fails the cement matrix crushes and the aggregate shears and crushes. I doubt such a flexible concrete would be used for a structure for uses such as an office building. Flexing under load may be within the limits of this concrete, but it isn't very comfortable.
The cracking is due to the ice entering cracks and freezing, thawing, and freezing again in the larger and propogated cracks.
To ensure good freeze-thaw strength, air entrainment is used to allow the ice to expand.
Cracked concrete is not always a bad thing! Concrete forms, when designed correctly, take into account cracking over its servicable life. When you are driving, look at the bridges you go under, there are cracks and chunks of concrete missing.
This is not unsafe. The concrete at the top of the beam is in compression (which we want), and at the bottom the concrete is in tension (which is a bad thing). BUT, that concrete in tension is only used as a cover to prevent rebar from rusting. Removing chunks of that tension concrete is not decreasing the overall strenght of the beam, as long as the steel rebar is not exposed.
Is it just me or do the controllers hook up to the PSX the same retarded way as my Atari.
The X-Box has yet to turn a profit for the Home & Entertainment division at Microsoft. -2.3 billion in video games.