Talk:Reinforced concrete

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[edit] Concrete versus Reinforced concrete

This article (reinforced concrete) contains some information that belongs with the article (concrete). The content on reinforcing need to be reinforced. Gregorydavid 07:06, 14 May 2006 (UTC)

Reinforced concrete normally refers to structural grade concrete that is reinforced by means of high tensile steel reinforcing bars which have a deformed surface and mild steel bars which are smooth.

Reinforced concrete design relates to the structural analysis of beams, slabs and columns. The resulting design yeilds the required amount of main tensile reinforcing, secondary compression reinforcing and shear reinforcing in the form of stirups.

Concrete technology relates to all the chemistry and workability issues..

So we have three articles Concrete, Reinforced concrete and Prestressed concrete.. can we merge all th relevant parts? Gregorydavid 18:49, 9 August 2006 (UTC)

[edit] Questions awaiting answers

[edit] Fertilizer induced spalding

In agriculture wharehouses where nitrogen fertilizers are stored, one sees the reinforced concrete bins spalding after just a few years of use. Does anyone know the chemical reaction that is weaking the concrete? nitrogen (N) + phosphorus pentoxide (P2O5) + potassium oxide (K2O) + calcium carbonate (CaCO3) ->?

[edit] Cutting and replacing reinforced concrete

If you need to cut a section of a reinforced concrete slab, is there any standard for tying in newly poored concrete to preserve the integrity of the reinforcing? I understand that you may be able to cut in new re-bars into the existing concrete but am unclear re how this is done to ensure safe load transfer from the old to new concrete. Can someone please advise how this is done?

Wikipedia isn't the place for homework questions, but here's the answer: Holes are drilled into the existing slab, and dowels placed into the holes, held securely with epoxy. The length which the dowel extends into the existing slab, the length which the dowel extends into the new concrete, and the connections between the dowels and the new reinforcing are determined by the structural engineer, subject to building code constraints. Argyriou 07:04, 22 August 2006 (UTC)

[edit] Production of spun concrete poles

What is the most effective way of producing spun concrete poles?

Who supplies the machines in Africa, the Middle East?

[edit] FRP materials

Thebluejay wrote


"Because FRP materials are linearly-elastic to failure, FRP-reinforced concrete elements will typically exhibit more brittle structural behaviour than those elements reinforced with traditional steel rebars. FRP-reinforced elements also exhibit vastly reduced fire-resistance. These two considerable weaknesses have limited its use to only extremely specialized applications."

I can't agree directly on this. Testing on our lab (Norwegian Building research Institute) shows that FPS (plastic fibres) is as ductile as steel - they adsorbe the same ammount of energy without beeing more brittle than steel. We have not tested Carbon based FPR. As to fire resistance this is of course dependent of the temperature where the FPR looses it's effect, and do varry from FPR to FPR. Removed the section from the page untill someone gets up with something better..... Oyvind 08:24, 11 October 2005 (UTC)


[edit] Physics and statics

[edit] Anchor length

Although the ridges on rebar offer increased surface area to resist tension forces, sometimes there is not enough embedment of reinforcing steel in the concrete to fully transfer tensile forces between the concrete and rebar. In these cases the rebar may be bent into a 90 degree hook, which itself will transfer half of the capacity of the rebar between the rebar and concrete.

This needs more detail to be understanable to a non-engineer reader. Okay, I took a stab at it, I may be wrong...

Hi, this discussion deals with the anchor length required so that bars do not pull out when they are subjected to tension or pulling forces. Test and theorerical calculations based on the condition where the steel bar begins to yield and the grip between the concrete and the steel begins to happen simultaneously give a required lap length equivalent to about 42 diametre of the bars to be anchored or lapped. Bars with hooks require a shorter anchor length.

Gregorydavid 06:57, 14 May 2006 (UTC)

[edit] Exclaimation Points

They just sort of make the article look silly. Reinforced concrete, while certainly a marvel of modern architecture, is not that exciting. 66.82.9.90 22:11, 2 July 2006 (UTC)

I got rid of the last two. Argyriou 23:26, 2 July 2006 (UTC)


[edit] Concrete Cancer

I don't understand the relevance of this section. Concrete cancer simply doesn't exist! Alkali-silica reaction, HAC conversion and sulfate attack are deterioration mechanisms in their own right and should be upgraded accordingly.Kpeyn 22:21, 19 July 2006 (UTC)

[edit] use in military enginering

shouldn't there be at least a link to fortress or a mention of the extensive use of reinforced concrete buildings in the early 20th century like the maginot line of fortress's?

[edit] uses

shouldn't there at least be some mention of the many uses of reinfoced concrete e.g. military enginering Askin 18:31, 11 December 2006 (UTC)

[edit] Diagram

Possible diagram with the rebar or other materials that make reinforce concrete, in .svg file. Thanks. —Preceding unsigned comment added by 68.103.252.156 (talk) 05:26, 21 January 2008 (UTC)