Why mobile pumping batching plants can’t be compared by equipment price

1 Introduction
2 Factors affecting the equipment comparison
3 Whole-life and project costs
- 3.1 Installation and relocation
- 3.2 Pumping requirements
4 Matching equipment to the project
5 Comparing quotations
6 Conclusion
7 Related articles on Designing Buildings

[edit] Introduction

When contractors compare concrete production equipment, purchase price is often one of the first figures considered. However, for projects requiring both concrete batching and pumping, comparing equipment prices alone can give a misleading picture of the overall cost. The relevant comparison depends on the complete equipment configuration and the costs of transporting, installing, operating, maintaining and relocating the equipment.

A mobile concrete batching and pumping plant combines functions that may otherwise require separate items of equipment. Depending on the configuration, this can include aggregate batching, weighing, mixing and concrete pumping. It should therefore be compared with alternative arrangements on the basis of the complete concrete production and placement process rather than against a batching plant with a different scope of supply.

[edit] Factors affecting the equipment comparison

[edit] Scope of supply

The quoted price of a concrete plant does not necessarily represent the same scope of supply as the price of another plant. Two machines may have similar nominal production capacities while having substantially different functions and configurations.

Before comparing prices, contractors should establish whether each quotation includes:

Concrete mixing system.
Aggregate batching and weighing system.
Cement, water and admixture dosing systems, where required.
Concrete pumping system.
Control system.
Power supply or generator, where required.
Conveying and feeding equipment.
Chassis or transportation system.
Ancillary equipment, accessories and initial spare parts.

A mobile batching plant designed primarily for batching and mixing may require additional equipment to transport and place the concrete. An integrated batching and pumping plant may combine some of these functions in a single machine. The two arrangements therefore cannot necessarily be compared directly on their purchase prices.

[edit] Production capacity and utilisation

Nominal production capacity is an important specification, but it is not by itself a measure of the economic performance of a plant. Actual output depends on factors including the mix design, aggregate handling, loading and batching cycles, mixer capacity, pumping requirements, site logistics and the availability of materials.

The expected utilisation of the equipment is also important. A plant with a high nominal capacity may not provide an economic advantage if the project requires relatively small or intermittent quantities of concrete. Conversely, a lower-capacity machine may be inadequate where sustained production is required.

The comparison should therefore consider the concrete output required by the project, the duration and pattern of demand, and the extent to which the equipment can operate at an effective utilisation rate.

[edit] Supporting equipment and labour

A lower purchase price can become less significant if additional equipment and labour are required to complete the same operation.

For example, a conventional arrangement may require separate batching or mixing equipment, concrete delivery equipment and a concrete pump. Depending on the project, additional operators may also be required to operate and coordinate the separate systems.

An integrated mobile batching and pumping plant can combine several of these functions. This may reduce the number of equipment interfaces and simplify material handling and concrete placement. It does not, however, eliminate the need for trained operators or other site resources.

The appropriate comparison is therefore the labour and equipment required to produce and place the required volume of concrete, rather than the number of functions incorporated into an individual machine.

[edit] Whole-life and project costs

A more comprehensive comparison considers the total cost of using the equipment over the expected project period. Relevant costs can include:

Equipment purchase or finance costs.
Transportation to and from site.
Site preparation.
Installation and commissioning.
Labour and operator costs.
Fuel or electricity.
Water and other operating requirements.
Auxiliary equipment.
Routine maintenance and repairs.
Consumables and spare parts.
Relocation between work areas or sites.
Downtime and associated production losses.

The relative importance of these costs depends on the project. For a long-term installation with high utilisation, purchase price and operating efficiency may be particularly significant. For projects involving frequent relocation, transport, installation and recommissioning can have a greater effect on overall costs.

[edit] Installation and relocation

Construction sites can change significantly as work progresses. Road construction, bridge construction, tunnelling, hydropower and other infrastructure projects may require concrete production equipment to be moved as the construction work advances.

Mobility can reduce the resources required to relocate a plant, but the term mobile does not necessarily mean that relocation is simple or inexpensive. The equipment's dimensions, transport weight, dismantling requirements, lifting requirements, access conditions and site preparation requirements should all be considered.

Questions to consider include:

How many transport vehicles are required?
What preparation is required before the plant can operate?
Is a foundation or prepared hardstanding required?
What lifting equipment is needed for installation?
Can the equipment be transported using standard arrangements?
How long does installation and commissioning take?
How long does recommissioning take following relocation?
What services, such as electrical power and water, are required?

These factors can affect the cost of a mobile plant substantially over the duration of a project.

[edit] Pumping requirements

Where concrete has to be delivered to elevated, distant or otherwise difficult-to-access placement points, pumping capacity and configuration become important elements of equipment selection.

The suitability of a concrete pump depends on factors including required flow rate, pumping distance and height, pipe or hose configuration, concrete characteristics and site conditions. The concrete mix must also be suitable for pumping through the proposed system.

Consequently, a batching plant with a nominally attractive purchase price may not provide the lowest overall cost if a separate pumping system is subsequently required. Conversely, an integrated pumping system may not be advantageous where the project has little need for pumped concrete.

[edit] Matching equipment to the project

The most appropriate equipment configuration depends on the characteristics of the construction work rather than on equipment price alone.

For smaller or medium-sized projects, an integrated mobile system may reduce the number of separate equipment interfaces and simplify deployment where the required production rate is within its capabilities.

For remote or difficult-to-access sites, transport requirements, available space, site preparation and the ability to relocate equipment can be particularly important. The costs of supporting the equipment throughout the project should be included in the assessment.

Where concrete is required at multiple placement points, pumping capability can also influence the overall efficiency of the operation. The assessment should consider the complete route from the storage and batching of constituent materials through mixing and pumping to final placement.

[edit] Comparing quotations

A useful comparison can be made by preparing a project-specific cost assessment for each equipment configuration. The assessment should first define the required concrete production rate, total volume, mix requirements, pumping requirements, operating period and expected relocation frequency.

The capital and operating requirements can then be assessed, including transportation, installation, labour, energy, maintenance, auxiliary equipment and downtime. Where equipment is being purchased for use on more than one project, expected utilisation over its service life can also be considered.

This approach allows a mobile batching and pumping plant to be compared with separate batching, transport and pumping arrangements on an equivalent basis. It also helps distinguish between differences caused by equipment specification and differences caused by the way in which the equipment is deployed.

[edit] Conclusion

The purchase price of a concrete production plant is only one component of the cost of producing and placing concrete. Equipment configuration, production capacity, utilisation, supporting equipment, labour, transportation, installation, pumping requirements, maintenance and relocation can all affect the overall economics.

Mobile batching and pumping plants combine functions that may otherwise be provided by separate items of equipment. Their suitability therefore depends on the requirements of the project and the costs associated with the complete concrete production and placement process.

Comparing equipment on this basis provides a more meaningful assessment than comparing purchase prices for machines with different functions or scopes of supply.