Volumetric Concrete: Mixed on Site, Paid by What You Use

What it is

A volumetric truck carries cement, aggregate, sand and water separately and mixes them on your site, metre by metre, as you need them. A standard truck mixer arrives with a fixed quantity of already mixed concrete and a clock running on it.

When it is the right answer

Small pours. Below the minimum load, a truck mixer charges you for the drum rather than the concrete. On a two-metre pour that surcharge can approach the value of the material.

Uncertain volume. Foundation trenches and underpinning are the classic case. You do not know the true volume until the excavation is open, and the ground in Nairobi rarely matches the drawing. Black cotton in Lavington and Kilimani over-excavates; shallow rock in Lang’ata under-excavates.

Several grades in one visit. Blinding at Class 15 and the footing at Class 25 without ordering two separate deliveries.

Long or interrupted pours. Material stays dry until it is mixed, so a hold-up costs you time rather than a load of concrete.

What it costs you

More per cubic metre than a full truck mixer load. Volumetric wins on small, uncertain and multi-grade work, and loses on a straightforward large slab where a truck mixer is simply cheaper per metre. We will tell you which of those you have rather than sell you the one we would prefer.

The honest limitation

Consistency depends on calibration. A well-maintained and correctly calibrated volumetric truck produces concrete every bit as good as a plant; a neglected one does not, and you cannot see the difference in the chute. Ask for cube results. Anyone offering this service and unwilling to provide them is asking you to take the strength of your structure on trust.