4

No, they are usually fitted once and left. If you need to remove them then you need to drill new holes. Or you should consider fitting a wooden framework to the concrete and attaching to that so it can be easily removed and refitted, without disturbing the concrete fixings.


2

Some other answer have touched upon this, but I think it needs to be made explicit: Your mistake is in thinking that civil engineering is about making the lightest structure possible. It's not. Instead, it's about making the most cost-effective structure possible. Give me a material that weighs a billion tons per cubic centimeter but is cheap enough to let ...


2

I will make a slight add to the answers given here already, as follows. Take the case of a bridge. When loaded, some parts of it will be in compression, other parts will be in tension. The designer's job is to manage the stress levels in the most cost-effective manner. If a certain amount of concrete is capable of handling the compressive stresses less ...


2

Using conditions given in the sketch above, let's do a parameter study. M = AsFy(d - a/2) a = Asfy/0.85fc'b, note, since As, b, fc' and fy are constant throughout this exercise, "a" is constant as well. Let's assume a = 50mm. d = 65, M1 = AsFy(65-50/2) = 40Asfy d = 115, M2 = AsFy(115-50/2) = 90Asfy d = 165, M3 = AsFy(165-50/2) = 140Asfy M2/M1 = ...


1

You are looking at a diagram for an infinite duration of loading, which is noted by the $\infty$-symbol. For a limited duration of loading, refer EN 1992-1-1 annex B.1. Just for clarity, the time shown on the first diagram, $t_0$, is the concrete age when loading starts, which is why the creep coefficient decreases with increasing $t_0$.


1

You are missing seepage with humidity. Seepage is the infiltration of water into the living space (basement) and makes the space wet or moist. It does cause concern about humidity, but seepage alone won't cause the humidity to reach the extent that is uncomfortable (for humans) and harmful for building materials. It needs to work with the elevated ...


1

A partial listing ( in addition to the previous answer) ; for reinforced concrete only simple generic shapes are needed ( bars) while steel only needs "I" , "H" beams, gussets, fasteners, welding . Careful inventory control of the previous steel items. Coating of these shapes to reduce rust during construction. Inspection to verify the ...


1

The most important advantage of reinforced concrete over pure steel structure is availability. Many countries/regions on earth rely on imports for general goods production needs, the cost of steel can run prohibitively high compared to concrete. The next advantage is weight. In certain types of structure weight counts, such as underwater powerhouse. However, ...


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