The idea was that the prep time before casting would be shorter, allowing more elements to be cast in parallel, and with smaller elements, fewer cranes are needed, and perhaps not even a crane at all. Instead, they can be positioned with an excavator that lifts them into place since cranes cost money to have on construction sites. If a large crane is needed, I understand the desire to minimize the number of lifts as it takes about the same amount of time to hoist and position a large piece as a small part. But for that, a proper crane is required, and as mentioned, they cost a fortune, and just erecting it with a foundation is a considerable sum.
This leads to the point that with smaller and lighter elements, a large crane may not be necessary, particularly if the construction is not tall, as in the case of houses. A mobile crane or even a small mobile crane or excavator, or the crane attached to the truck that lifts the parts into place, would suffice, eliminating a major cost. However, this is more applicable to small constructions and not comparable to building a shopping center or similar projects.
This leads to the point that with smaller and lighter elements, a large crane may not be necessary, particularly if the construction is not tall, as in the case of houses. A mobile crane or even a small mobile crane or excavator, or the crane attached to the truck that lifts the parts into place, would suffice, eliminating a major cost. However, this is more applicable to small constructions and not comparable to building a shopping center or similar projects.
It's similar to how Alfa Stenhus builds their floor structures (as I commented in an earlier post), but they don't have a steel beam at the bottom, only a wooden beam attached with metal truss fittings in a 60mm concrete slab with embedded floor heating and floor drains. So the tensile forces at the bottom are taken up by the wooden beam, and the slab at the top takes up the compressive forces at the top, and the truss in between is only there to increase the distance and thereby achieve a higher flexural rigidity. It may be smart to do as you suggest and combine the wooden beam with a metal U-beam, making the construction a little less susceptible to moisture.miry said:
There are also some U-beams made of concrete, for example from LKB, where they use a similar concept and create height on the slab without it needing to be massive.
Rickard saw something earlier where they had a steel truss that they tied together with reinforcement and a concrete slab, and it was meant to be reversible so you could have the truss facing either downwards or upwards. The idea was that if you had it on the topside, you could direct heated air there, then lay the floor on the steel frame to get air-based floor heating, and then they had a gap at the floorboard so the ventilated air came in along the floor.
And then, comparing wood to steel, steel has about 50 times the strength of wood and doesn't change depending on humidity. My suggestion was to utilize both the tensile strength of wood and steel, but the main reason for using wood was to make it easier to screw the ceiling underlay to the joists.
Then there's corrugated sheet metal with loops and fixed reinforcement; if you embed it, you have a closed form with reinforcement ready, but it's more of an intermediate between building formwork and prefab since the form itself becomes part of the load-bearing structure, so it doesn't quite belong here.
Then I'm someone who never liked calculating concrete as it has such varied properties when intact and when it has been loaded and cracked. I never understood how to calculate crack width to prevent the reinforcement from rusting, but that was a long time ago, and it would be nicer to calculate if it behaved like wood or steel. But wood has its disadvantages, changing over time and losing strength depending on moisture level and how long it's exposed to it and how heavily it is loaded, but that was OT. It would be easier just to calculate one thing, but then concrete has such low strength if you don't account for reinforcement, which I find a bit trickier. However, it is facilitated by computer programs that calculate it for you, instead.
And then, comparing wood to steel, steel has about 50 times the strength of wood and doesn't change depending on humidity. My suggestion was to utilize both the tensile strength of wood and steel, but the main reason for using wood was to make it easier to screw the ceiling underlay to the joists.
Then there's corrugated sheet metal with loops and fixed reinforcement; if you embed it, you have a closed form with reinforcement ready, but it's more of an intermediate between building formwork and prefab since the form itself becomes part of the load-bearing structure, so it doesn't quite belong here.
Then I'm someone who never liked calculating concrete as it has such varied properties when intact and when it has been loaded and cracked. I never understood how to calculate crack width to prevent the reinforcement from rusting, but that was a long time ago, and it would be nicer to calculate if it behaved like wood or steel. But wood has its disadvantages, changing over time and losing strength depending on moisture level and how long it's exposed to it and how heavily it is loaded, but that was OT. It would be easier just to calculate one thing, but then concrete has such low strength if you don't account for reinforcement, which I find a bit trickier. However, it is facilitated by computer programs that calculate it for you, instead.
I have sketched a bit on a house that has many recurring parts that I want to build (only one house). Considering several comments in this thread about the mass production advantages not being so great for villas, I'm wondering if I was wrong on that point. Do the gains from mass production become so small that the disadvantages of small elements with lots of angles, etc., take over?
I have drawn two versions: one "full" version with an attached garage that has many small custom elements where there is not as much mass production but some for a few elements:
Link to PDF for full version
And a budget version where the garage is not built from the start but can be built later, either together with the house or separately, and there are no small custom pieces since the garage is separate, significantly more mass production (at least compared to the full version):
Link to PDF for budget version
Are my sketches reasonable regarding the concrete elements? Is the gain from mass production eaten up by skewed angles and small elements?
I have drawn two versions: one "full" version with an attached garage that has many small custom elements where there is not as much mass production but some for a few elements:
Link to PDF for full version
And a budget version where the garage is not built from the start but can be built later, either together with the house or separately, and there are no small custom pieces since the garage is separate, significantly more mass production (at least compared to the full version):
Link to PDF for budget version
Are my sketches reasonable regarding the concrete elements? Is the gain from mass production eaten up by skewed angles and small elements?