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Animatstoday at 6:10 PM4 repliesview on HN

Hand-held devices for testing concrete properties would be more useful. Most concrete problems come from a bad mix - too much water, not enough cement, etc. Concrete testing usually involves cutting a core out of the poured slab and sending it to a lab. Something where you stick a probe in the mix and can reject it before pouring would help. Here are some on-site concrete testers.[1] They're heavy and a pain to use.

There should be an app for this. But that's so last-decade.

[1] https://store.forneyonline.com/concrete-testing-equipment/fr...


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munk-atoday at 7:37 PM

> too much water, not enough cement, etc.

I wanted to mention that Concrete is far more complex and regional than folks might imagine. The quality of gravel and sand, local impurities - these all contribute massively. It's probably best to think of it like a wine's terroir - except, unlike a bottle of wine, it's prohibitively expensive to ship both the components and the finalized mixture to different areas. If a region's limestone has a massive clay impurity then it may simply be unsuitable for large structures or require extensive filtering to the point of being uneconomical.

It's important to be aware of just how much the local geological mix can impact the viability of building with concrete because while theoretically we could use perfect concrete for every project - at that point most projects would simply be too expensive to consider undertaking. There is a very large field of engineering around establishing the realism required in settling for what you've got for the price you can afford in. It can absolutely mean that the materials required to build a high rise in Philly might be priced starkly differently from the same structure planned in Milan even with adjustments for the labor impact on pricing.

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MisterTeatoday at 6:43 PM

On-site, before pouring, they use the slump test: https://en.wikipedia.org/wiki/Concrete_slump_test

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harimau777today at 6:15 PM

I'm surprised the ratios for a given situation isn't standardized by now. Is it just people cutting corners?

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no_shadowban_6today at 7:16 PM

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