I'm no expert, but here's what I've learned so far.
1. Developers prefer flat-plate reinforced concrete construction for residential buildings because it allows greater ceiling height for each apartment unit compared with steel skeleton construction (for the same height-perfloor).
They also go with flat-plate construction because each apartment building requires its own HVAC controls, meaning there's no need to uniformly ventilate large areas. This means that the developers only need to provide HVAC water piping for the whole building as well as HVAC units in each unit (it's usually either 4-pipe fan unit system or geothermal heat pump system). This avoids the need to run bulky ductwork throughout the ceiling as well as the need to carve out precious real estate to house large mechanical rooms on each floor to store the air handler units and other HVAC equipment.
2. In contrast, commercial high rise buildings DO have a need to uniformly ventilate large areas with ductwork and vents. The difference in ceiling height between flat-plate and steel construction is directly attributed to the beams and girders running between the steel columns. Mechanical engineers use the otherwise wasted space between the beams and girders to run ductwork to transport conditioned air throughout the floor. That space is also used to run electric, data, and telephone cabling.
3. The main advantage of pre-cast concrete panels over poured concrete floors is simple: it's much faster to install. The concrete in the panels is also typically stronger than poured concrete because it has been steam-cured in a controlled environment (though that strength is mitigated somewhat by the holes in hollow core precast panels). The hollow cores in the panels also provide an area to run cabling.
There are a few disadvantages to pre-cast concrete. One is that grout filler on the joints between panels require periodic maintenance to prevent water from infiltrating in. Another is that because pre-cast panels are usually hollow-core planks, they provide worse sound insulation compared with heavier poured concrete (as mass is a good sound insulator). And another is that they provide worse fire protection compared with heavier monolithic poured concrete slabs.
And finally, the installation of the structural-only portion of steel construction is typically faster than poured concrete construction because it only entails connecting different beams, girder, and columns pieces together. However, because poured concrete construction requires less of the other aspects of construction (by boon of its inherent properties, such as its built-in fireproofing, and by boon of its intended design use, such as in less-stringent residential construction), it is typically faster to build the overall finished structure with it compared with steel commercial construction.
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I take the high road because it's the only route on my GPS nowadays. #selfsatisfied
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North American Structure Types
Linear Mode
