After every concrete delivery, the chute, the tyres, the hopper and, from time to time, the inside of the drum stay in contact with cement, aggregates, water and any admixtures. If these materials are not dealt with, they form deposits. Once hardened, those deposits take far more time and money to remove than fresh residues.
Anyone who runs a fleet of truck mixers knows that internal build-up reduces mixing capacity and drum output. A truck taken out of service to remove hardened deposits is also unavailable for scheduled deliveries, so residue management affects the operational continuity of the whole fleet.
This article follows the job from start to finish. It covers what happens at the end of discharge on site and on return to the plant, and how truck mixer cleaning is carried out on the outside, on the inside and in the cases that require physical access to the drum. It then looks at where water and residues end up after washing and what to assess when organising the process, including when it makes sense to talk to a CIFA expert.
Once discharge is complete, and before leaving site, the operator secures the truck and cleans the parts that have been in contact with the concrete, in particular the discharge chute and the tyres. This should take place on a paved area equipped to collect wash water, never at a random spot on the site.
The positioning of the truck and the destination of water and residues follow the instructions of the site manager. Before cleaning, the operator applies the brakes and places chocks under the wheels. Once safely up on the platform, the operator washes the outside of the truck only when there are no overhead power lines nearby, always wearing the required PPE.
For as long as anyone is on the platform, including after washing, the drum must never be left rotating. Rotating parts, or the ladder closing, create a risk of cutting, shearing and abrasion.
Internal washing of the drum, with discharge into the reclaiming system, does not take place at this stage. As standard procedure it happens on return to the plant at the end of the day.