By 1929 there were over 100 plants operating in the United States. Some sources suggest as early as 1913 in Baltimore. There is some dispute as to when the first ready-mix delivery was made and when the first factory was built.

4.1 Transit mixed ready mix versus volumetric mixed ready mix.

However it was estimated at just under 500 billion dollars in 2018. It was estimated at 650 billion dollars in 2019. The global market size is disputed depending on the source.

An admixture is often added to improve workability of the concrete and/or increase setting time of concrete (using retarders) to factor in the time required for the transit mixer to reach the site.

All aggregates should be of a washed type material with limited amounts of fines or dirt and clay.

It is a mixture of Portland or other cements, water and aggregates: sand, gravel, or crushed stone. Ready-mix concrete refers to concrete that is specifically manufactured for customers' construction projects, and supplied to the customer on site as a single product. However, other sources divide the material into three types: Transit Mix, Central Mix or Shrink Mix concrete. This delivers the ready mix in a dry state and then mixes the concrete on site. The second is the volumetric concrete mixer.

This type of truck delivers concrete in a plastic state to the site. There are two types with the first being the barrel truck or in–transit mixers. Ready-mix concrete ( RMC) is concrete that is manufactured in a batch plant, according to each specific job requirement, then delivered to the job site 'ready to use'.

Ready mix driver job description