A batching plant cannot sell its theoretical output if mixer trucks are not available at the discharge point. Fleet planning starts with the amount of concrete that must be delivered per hour, but the decisive input is the complete truck cycle: queue, loading, travel, site waiting, discharge, return and washout.
Use delivered demand, not plant nameplate capacity
Start with the peak concrete volume that customers or the project actually need during a defined hour. Divide that demand by the legal usable concrete volume per truck to estimate departures per hour. A nominal 10 m3 drum does not automatically carry 10 m3 legally; chassis tare weight, concrete density and local axle limits determine the usable payload.
A practical first calculation is: required trucks = hourly delivered demand multiplied by average round-trip cycle time, divided by usable volume per truck. If demand is 60 m3/h, usable truck volume is 8 m3 and the full cycle is 90 minutes, the arithmetic starting point is 11.25 trucks. The operating plan must round upward and include an availability reserve. This is an example of the method, not a fleet recommendation for every site.
Measure the entire cycle
- Plant queue and loading time, including ticket and quality release.
- Outbound travel under realistic traffic and road conditions.
- Waiting and discharge time at the pump, pour or customer site.
- Return travel, washout, inspection and refuelling.
- Maintenance downtime and the percentage of trucks normally unavailable.
One delayed truck can affect the vehicles behind it, especially when a project controls discharge from one pump. Use normal and peak cycle times instead of one optimistic travel estimate.
Match truck size to road law and batch size
Larger drums reduce trips only when the route and chassis can carry the load. Check gross vehicle weight, axle limits, bridge restrictions, turning radius and access to the discharge point. The plant batch size should also divide into practical truck loads without creating avoidable partial batches or long waiting between charges.
Connect dispatch with quality control
Fleet planning is also concrete-quality planning. Long queues increase concrete age, while adding water at the jobsite to recover workability can change the approved mix. Define who may release a truck, how slump and sampling are recorded, and what happens when the site cannot receive concrete. The laboratory, control operator and dispatcher need the same order and recipe information.
Information needed for a fleet proposal
- Peak and normal delivered demand in m3/h.
- Average and maximum one-way distance, traffic and road gradient.
- Legal payload and preferred chassis available in the destination market.
- Average loading, waiting, discharge, return and washout time.
- Number of shifts, maintenance reserve and local service support.
Calculate with two cycle scenarios
Do not plan the fleet from one average. Build a normal scenario and a constrained scenario. For example, at 48 m3/h with an 8 m3 legal load, the plant needs six departures per hour. If the normal round trip is 75 minutes, the mathematical requirement is 7.5 trucks. If peak traffic and jobsite waiting extend the cycle to 105 minutes, the same demand needs 10.5 trucks. Rounding the first result to eight trucks leaves the plant short whenever the constrained cycle occurs. The dispatcher should know which cycle applies by route and time of day.
Convert fleet size into a dispatch interval
Hourly demand is easier to operate when converted into minutes between departures. At 60 m3/h with 8 m3 loads, one truck must leave about every eight minutes. Compare that interval with the time required to load the truck from the selected mixer. If the plant needs four mixer batches and each complete batch cycle is longer than two minutes, the dispatch target cannot be maintained without overlap, buffer capacity or a different plant configuration.
Include availability rather than adding a random truck
Fleet reserve should reflect actual maintenance and operating records. Tyres, brakes, hydraulic drive, drum rollers, water system and chassis service can all remove a truck from dispatch. If historical availability is 90%, divide the operating requirement by 0.90 instead of simply adding one vehicle. Eleven trucks required in operation would mean 12.2 owned units at that availability, so the commercial decision is normally 13 owned trucks, a rental agreement or a lower committed peak rate.
Warning signs that the fleet, not the plant, is limiting sales
- The mixer waits with completed concrete because no truck is under the discharge point.
- Dispatch intervals become irregular even though batching cycles remain stable.
- Trucks return in groups after a jobsite delay, creating a queue and then a gap.
- Concrete rejection or workability complaints rise on the longest routes.
- Operators increase water or drum speed to compensate for poor scheduling.
Make the fleet decision commercially
Buying enough trucks for the single busiest hour may leave expensive assets idle during normal demand. Compare owned, contracted and mixed fleets against route reliability, customer penalties and local rental availability. The correct fleet is the one that protects the promised delivery window at an acceptable utilization rate, not the largest number the capital budget can support.
Compare the 6-16 m3 concrete mixer truck range with the ready-mix plant planning guide and the Indonesia HZS180 ready-mix reference. Send the route, legal weight limits and delivery schedule through the quotation page before selecting drum capacity or fleet quantity.