Concrete Production and Characteristics: A Comprehensive Look

Posted on Feb 26, 2025 in Hotel Administration and Management

Concrete Production and Characteristics

Central Concrete Production

Central concrete production facilities must include:

  • Storage of raw materials, arranged with pollution control measures.
  • Metering installation with silos and hopper scales.
  • Mixing equipment (fixed or mobile) capable of producing a homogeneous and completely mixed product.
  • Transport equipment.
  • Quality control services.

Ready-Mixed Concrete

Ready-mixed concrete is manufactured in a plant separate from the construction site.

It facilitates execution, especially in urban areas or near power sources.

It offers economic advantages by reducing labor and improving quality through greater uniformity and consistency.

Generally, ready-mixed concrete is supplied already mixed.

Ready-mix concrete can also be supplied dry, consisting of a pre-dosed mixture of cement and aggregates, powder, and optional additives, without mixing water. This is advantageous in hot climates where water loss during transport can occur, and when the distance between the factory and the work site is significant.

Kneading (Mixing)

Ready-mixed concrete is dosed centrally and can be kneaded using a fixed mixer or a mobile mixer truck. Mixing should occur before transport.

During transport in the truck mixer, the drum rotates at a stirring speed (to prevent segregation) rather than a mixing speed.

Standard mixer trucks in Spain carry a concrete volume of 5-6 m3.

If using superplasticizers, add them shortly before unloading due to their limited effectiveness over time. After adding the additive, re-knead the concrete until the fluidizing agent is evenly distributed.

Upon arrival at the work site, require approximately 30 revolutions of re-mixing.

Concrete Designation and Characteristics

Concrete for a project can be ordered from the supplier based on properties or dosage.

Specifications for Ordering:

  • Consistency
  • Maximum aggregate size
  • Type of environment to which it will be exposed
  • Characteristic compressive strength (if designated by properties)
  • Cement content in kg/m3 (if designated by dosage)
  • Indicate whether the concrete will be used in mass or prestressed applications.

Designation by Properties:

When designated by properties, the supplier determines the concrete mix composition to ensure:

  • Maximum aggregate size
  • Consistency
  • Characteristic strength
  • Cement content
  • Cement ratio

Designation by Dosage:

When designated by dosage, the requester is responsible for the specified characteristics: maximum aggregate size, consistency, and cement content per m3 of concrete. The supplier must guarantee and indicate the water/cement (A/C) ratio used.

  • If the construction manager does not prohibit the use of additives, the supplier may use them, informing the requester without needing authorization.
  • Additions (e.g., fly ash) should not be used without the knowledge of the requester and permission from the Director of Works.

Designation Format:

The designation format for properties is: T – R / C / TM / A