are there any estandard for self compacting concrete?
149815
The only organizational standard for SCC that i'm completely aware of is from the Precast/Prestressed Concrete Institute and it was an interim standard.  It describes the testing methods as well as some other suggestions.  Below is a link to the Adobe Acrobat file.
714809
The previous answer is almost correct, except that concrete actually set under water.  So they just have to make a form, put reinforcing steel in it, and pour concrete in the form in a way that displaces the water out of the form.  In time, concrete will harden even under water.\n\nFor you information, after concrete is poured, it is important to keep the concrete moist in the first 24 hours when it cures.
1018401
If there were a centrifuge large enough to spin a quantity of concrete mix at incredibly high speeds, you could separate concrete into its parts.  When a mixture (not a solution) is placed into a centrifuge, it is spun at great speeds and the constituent parts will separate out, those with greater mass will be forced to the bottom and those with less will remain at the top.  A gradient will form of increasing mass (and usually increasing density) from top to bottom.  With concrete you would have the supernatant liquid (water) on top, a series of silt layers and then the large stone and gravel pieces on the bottom.\nI hope that answers your question.  Why did you need to know such a thing?
527012
It is not possible for usng slar energy directly. because the compresser operations want frequent input. ( Not continuose). In the form Solar electricity is possible. \n\nHow ever Vapour Absorption syastem is possible
925948
Do you mean Particle board or MDF?\nBoth are used in low end furniture construction.\nThey are dense materials that will flex or bend significantly under a load.  They will swell when exposed to excessive moisture.\nMDF is denser and more durable, but neither is suitable for projects that will see a lot of abuse.  Solid wood is still king.\n\nThere is also a compressed natural wood product used for curved edges and moldings\nhttp://www.compwood.dk/eng_faq.htm
665018
According to BS 8110:Part 1, the structural use of concrete, precast concrete beam and cast in-situ beam can be designed using same design approaches and design criteria. But additional design criteria must be consider for precast concrete beam in resisting stresses caused by\n\nHANDLING\nSTORING\nTRANSPORTING\nERECTING\n\nBecause precast concrete beam is fabricated in factory, finished beam must be transported, stroed and erected. During these processes, different type of stresses will be exerted. This condition is absent in cast in-situ concrete.\n\nSecondly, design of connection for precast concrete beam is also very important to maintain its compatibility to the structure.\n\nThirdly precast concrete beam is also more affected by shrinkage and thermal expansion of concrete, thus movement joints must be design and adequtely supplied.\n\nFor more information about precast concrete design, please refer to BS 8110:Part 1 Section 5.
398777
Please mix bicarbonate with wood ash and use it biweekly
818381
Lower cost and Less weight.\n\nA properly designed Hollow Core Slab will have the same  or greater strength in load bearing characteristics as a Solid core Slab. The Hollow Core can be re-in forced by the Manufacturer\n\nsee the following URL for additional details:\n\nhttp://www.hollowcore.com.au/products/hcore/\n\nHope this assists you.
161897
how about you do your own research and homework.\n\nHere's my answer: 1 brick at a time until it's done.
813260
That depends greatly upon the mix design (what the concrete is made out of). Mix designs can put concrete anywhere from 50 lbs/CF (using very light weight rocks and other items), to over 200 lbs per CF.\n\nGenerally, most of your everyday concrete (3000 psi, Type II cement, run of the mill stuff) is about 150 lbs/CF, give or take a couple of pounds.
137197
If you are referring to shake table test for Concrete testing (i only know of it being a civil engineer) it is available in every engineering university of the country.\n\nIf you need any further details you may email me at: talhaiba@yahoo.com
362687
I found several sites using- tons of gravel per 100 sq ft - as the search term\nA couple sites are listed below.
768756
look for ones that are non-profit. Some articles for it are at http://www.234debtconsolidation.com
400030
Not sure this helps....there are other pages at this Portland Cement Assn site.  Browse around this site.\n\nhttp://www.cement.org/countonconcrete/Wall%20Systems%20Backgrounder.pdf
866685
If the soils removed from the excavation aren't too wet then use the same soils. \n Why do you have post tension cables on a slab on grade design?\n If you are trying to bring the subgrade level across the whole floor area to minimize the purchase of extra concrete ,then sand would prob. be the way to go.
938243
Relative compaction\n\nLaboratory compaction tests use different compactive efforts from those of many of the big machines so results from these tests cannot always be used directly to predict the maximum dry density values that will be achieved in the field. What can be used is the relative compaction, which is the percentage ratio of the in situ maximum dry density of the compacted fill material to the maximum dry density obtained with the relevant laboratory compaction test. Specification by end product compaction is when the contractor is directed to achieve a certain minimum value relative compaction and is allowed to select his own plant.
612809
A precast concrete frame(pcf) is a frame casted at a place other than the place where it has to be fixed.Sometimes due to certain reasons ie shortage of space,raw material,congenial atmosphere etc. a pcf is better in durability,stability and provides human comfort,environmental efficiency and is aesthetic also.