Several factors affect the performance of concrete handling equipment. Material factors have also been seen as important in equipment performance and due attention must be paid. Each construction material should be properly analyzed for suitability before construction work begins.
Some important analysis includes moisture content, construction suitability, chemical and physical properties and the type and size of particles in the material.
The source of sand is an important factor for construction. Sand sourced from saline/ salty environments is never recommended due to chemical composition and can have damaging effect even on the construction equipment. For construction, the compression ability of the sand must be tested. Sand with high compression is not suitable for construction.
This raw material makes up 60 – 75 percent of the volume of the aggregate mixture. It provides the volume stability of the finished concrete. One important quality factor that affects machine performance is aggregate size, which affects the shrinkage potential. Water and cement usage increases proportionately with decrease in aggregate size to offset the probability of shrinkage.
The Batching water quality is a consideration for mixing operations. The water used in concrete making is guided by guidelines such as the ASTN C94, and ASTM 1603. Non-potable water used in concrete mixing and batching plant operations can affect the machine performance and quality of product. Water resulting from concrete production processes, storm water run offs from the facility and others containing concrete aggregates has a maximum allowed solids content of 50,000 parts per million of the total mix. Anything in excess of this will lead to poor product.
Current designs in equipment have recognized the impact of excess water happening during the mixing process such as when rain occurs when work is going on. Increases in the volume of cement slurry due to dilution by water causes too much flow thus weaker mix while too little water may lead to collapse of the final product. This eventually affects the strength and durability of the concrete product.
Workability of Concrete
The type of aggregate used and mixing affects the workability. Reinforce concrete with high steel percentage creates a difficulty in compaction with concrete machines as well as handling with other equipments; It has low workability. Concrete with high workability is easier to handle during mixing and transfer operations, which utilizes machines such as concrete mixers etc.
Batching and Mixing
Mixing is best done using mixing machines or ready mix concrete plant. The self-loading dumper and self-loading cement mixers, offer good concrete handling solutions. The quality of material also has an effect on the blending process. The mixing time is dependent on the concrete mixer capacity as well as final concrete requirement. A drum mixer with a small diameter translates to greater velocity than that with smaller diameter. If stiff and rigid concrete is the end product, longer mixing time is required.
Ready mixed concrete requires transportation from one site to another. During transport, equipment used has an impact on the final product. Transport equipment must guarantee water/cement ratio is maintained, slump, air content and consistency is achieved.
While sourcing for concrete equipments it is important to source only from reputable concrete mixers manufacturers , and assured project success.