Concrete Box Innovation

[pug]

Precast concrete boxes have trouble competing against multiplate due to transport costs. If the box was twice as light, then it would be able to compete twice the radius. Any thoughts on ribbed walls on the inside? Yes, detractors would be reduced capacity, less abrasion resistance and more likely to catch drift inside the pipe. On the positive side, great for fish, enables larger boxes or longer lengths, less cost and lighter for transport.

Has anyone ever done this? Is it possible? To aid in thought generation, let me propose a starting point of 14" depth slabs comprising of 10" legs and 4" outside deck. Legs are 24" centers and 5" wide. Corners between legs and decks have a 4" champher. Legs could have prestressed strands in the roof but thinking the sides and floor can be simply reinforced. Not a fan of open floor boxes either so if we can avoid that for this exercise please.

Have to admit, I like concrete boxes over all other structures but becoming more environmentally friendly (fish and habitat)and lighter are important.

If you think that the added outside dimensions increase the weight anyway so why the effort to make it lighter. I also want to get more light into the pipe and the ends of the pipe will allow that when bigger (again, for fish). And another reason is when one wants to fill a space under an existing bridge as well.

Your thoughts are most welcome.

 

[ishvaaag]

Very thin concrete shapes are used in precast parts. This includes modules for post-tensioned roof beams with sections maybe around or under 2 cm thick. Thin modular walls for public works (around 5 cm thick) also include ribs (and even just bones) between the back of the wall and the footing. Lintels and plates for roofs also are available in these ranges of thickness. So there's no doubt about that thin concrete structural parts are being fabricated and sold.

Other thing is for specific applications if what would turn the design feasible from a viewpoint of cost is really at hand. You might end with a fabrication scheme in which the additional costs overpower the gains, so one needs to finetune the design, on which process one can realize that other alternatives in the market have the upper hand by whatever the reasons.