Pouring Concrete in Highrises

[Warm Worm]

When concrete is poured into the rebar molds and dries(?), what happens to the next batch of concrete the next day on top of the previous concrete-- specifically at the juncture between the two? Is there a crack and/or weak spot? Is the old concrete wet enough and/or new concrete heavy/wet enough to somehow merge and form a complete bond?

[gruhn]

There is an approach called "continuous pour" that iiuc is all about making sure the previous batch and the next batch get confused and think they are part of the same piece of concrete. Let me poke the web and see what it says... iirc St. Louis arch, CN Tower... that sort of thing, benefit from this tech.

Right, that bit of research didn't help. And my books are all packed up right now. Maybe somebody else can add real info. Talking about moving/crawling/walking forms might be interesting too, hint hint.

[Warm Worm]

Slipform:

concrete extrusion. Cool... I think that's kind of how spider-webs work too... "Although silk is produced as a liquid within the silk glands, it usually emerges from the spigots (as the spider moves away from an attachment point or pulls the silk out with its leg claws and bristles) as solid silk fibres. Different parts of the silk gland secrete different types of proteins (spidroins) into the gland cavity. These form an inner core and then outer sheathing layers. The very viscous silk flows as a liquid crystal fluid through a long, progressively narrowing duct whose lining cells extract water from the protein. It is then subjected to a mild acidic bath and increased pulling stress which help convert the liquid protein into a solid fibre."

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think I'll try extra-hard this week to quit caffeine.

[Warm Worm]

Corrrect.