Have you seen big cement trucks with the barrels that rotate? If so, you’ve seen ready-mix concrete being transported. Ready mix concrete is produced in a factory according to a set recipe and then delivered in an in-transit mixer. This type of concrete allows for a precise mixture that can be used on construction sites. Ready mix concrete has been around since the 1930s and is widely used today.
Ready mix concrete is made in a batch at a central location instead of being mixed on the job site. Each batch is tailor-made according to the contractor’s needs and is delivered in an unhardened state. Concrete is a mixture of Portland cement, water, sand and gravel or crushed stone and is usually sold by volume.
Ready mix concrete is usually best for jobs that require small amounts of concrete or intermittent placing of concrete. It can also be used for large jobs where there is limited space and not enough room for a mixing plant. The types of ready mix concrete include:
- Transit-mixed – the materials are batched at a plant and mixed in the truck during transit
- Shrink-mixed – concrete is partially mixed at the plant and is completed either in transit or at the job site
The truck that transports ready mix concrete is known as a transit mixer. Inside the truck, there is an Archimedes screw (a corkscrew-like tool inside the barrel) that mixes the cement by turning in a clockwise motion. In order to lift the concrete to the delivery chute, the screw turns counter-clockwise.
How ready mix concrete is made
Raw materials required:
- Water sets off a chemical reaction when it touches the cement.
- Aggregates are taken from quarries and aggregate banks and account for up to 75% of the ready mixed concrete’s volume.
- Additives are added to ready mix concrete before or during the preparation process. These can either improve the durability or reduce the water content in the concrete in order to shorten the time it takes to set.
- Cement gives concrete its resistance. The most commonly used types are grey Portland type and Pozzolana Portland type C-2.
These ingredients come together to produce a uniform mass of concrete during the mixing phase. As soon as the water is poured into the cement mixer and it starts rotating, this is when the mixing time officially begins. The mixer rotates two to six times per minute.
Advantages of ready mix concrete
- Guaranteed quality – it’s produced under controlled conditions
- Fast construction – it helps construction to move faster
- Reduction in cement consumption – better handling and proper mixing help to conserve the amount of cement used
- Improves durability and sustainability
- Delivered on time and with small pours
- Eliminates or reduces human error
- No need for space to store large amounts of materials like aggregate, cement and water
- Precise and reduces work site confusion
Disadvantages of ready mix concrete
- Cannot be placed right after mixing
- With long transit times, the concrete may set
- Admixtures may need to be added to minimize chance of setting
- Admixtures may cause loss of strength and require testing beforehand
- The mixer trucks are very heavy and the roads need to be strong enough to support them
The only ready mix concrete supplier you’ll need
If you need ready mix concrete, you can trust Spragues’ Ready Mix to do the job. Ready mix concrete is our specialty and you can use our ready mix concrete calculator to get an estimate on the amount you need us to deliver, or you can call one of our specialists to discuss your needs. We ship our concrete fast and efficiently from Los Angeles and the San Fernando Valley for professional or home projects. Call us at 844-547-0103 or visit https://srmconcrete.com/.