Tangentially related, but there is a new generation of trucks that mix the concrete on-site. They can output small batches and change the mix on the fly. They solve a lot of headaches!

https://cementech.com/volumetric-technology/

▲

m4rkuskk 3 hours ago | parent | next [-]

This may work on a small scale, not in most commercial use cases. A typical deck pour (400cy) will pour at 70-80cy/hr. you got 9-10cy/truck. Meaning you have 7 to 8 minutes to back in the truck, empty it into the hopper and leave. You barely have time to add water to the mix. Most high-volume concrete plants are "dry-batch", which means all the ingredients get dumped into the drum and the concrete will get mixed while driving to the project site. Also, changing mixes on the fly will not "fly". No one is going to authorize the adjustment, because what happens when the mix doesn't meet specs... It will need to get chipped out.

▲

ortusdux 3 hours ago | parent | next [-]

The target audience of these trucks is sub-10cy jobs. It allows companies to cater to smaller customers at a premium.

▲

bluGill an hour ago | parent | prev [-]

In the large road projects I've seen they bring a concrete plant to the job. Buildings still get trucks coming in.

	▲	ortusdux an hour ago \| parent [-]
		I highly recommend the 9 episode miniseries podcast The Big Dig from GBH. Their mismanagement of the concrete was wild.

▲

zozbot234 3 hours ago | parent | prev [-]

Concrete mixer trucks are not new at all actually, they've been around for a long time.

▲

richwater 3 hours ago | parent [-]

Traditional trucks pick up cement from a facility and rotate it to keep it from setting. They don't mix it on the fly. Any extra is considered waste is poured out.

▲

coryrc 2 hours ago | parent [-]

Where did you get the idea that rotating is "to keep it from setting" and not mixing?

	▲	ortusdux 21 minutes ago \| parent [-]
		https://en.wikipedia.org/wiki/Concrete_mixer#Concrete_mixing... "Special concrete transport trucks (in-transit mixers) are made to mix concrete and transport it to the construction site. They can be charged with dry materials and water, with the mixing occurring during transport. They can also be loaded from a "central mix" plant; with this process the material has already been mixed prior to loading. The concrete mixing transport truck maintains the material's liquid state through agitation, or turning of the drum, until delivery. " Y'all both right.