Enhancing Concrete Workability

Improve efficiency from batching to placement

Concrete workability is defined as how easily freshly mixed concrete can be mixed, placed, consolidated, and finished. Optimal concrete workability has the potential to reduce labor costs, minimize placement effort, and shorten the project schedule for a construction job. Utilizing chemical admixtures to improve workability can:

Help optimize concrete consistency and mixing time
Promote easier placement and pumpability
Facilitate consolidation
Enhance finishability

Mixing Concrete

To ensure homogenous distribution of a concrete mixture, the workability and mixing time must be optimized. This is especially true with lower water content mixtures. The following technology can improve the efficiency of the mixing process at the concrete plant:
High-range water-reducing admixtures rapidly disperse the cement in the concrete mixture to generate workability faster.

Placing and Pumping Concrete

Whether concrete is placed through a paving machine or pumped 100+ stories high, the following admixture technologies can help achieve the appropriate workability:
High-range and mid-range water reducers enhance the concrete’s mobility and fluidity, facilitating placement.
Viscosity modifying admixtures add body, rheology, and robustness to provide segregation resistance in highly fluid concrete and enhance pumping.
Rheology-modifying admixtures increase concrete lubricity to help stiff concrete extrude easily, and lower pump pressures in more fluid concrete applications.
A workability-retaining admixture provides flexible, but predictable, degrees of slump retention without retardation. It provides consistency in air-entrainment, slump, workability and strength, and minimize the need for jobsite slump adjustment using water or high-range water-reducing admixture.

Consolidating Concrete

A concrete mixture’s response to vibration determines how easily and how well it will consolidate. To improve a mixture’s response to vibration, the following technologies can be used:
High-range water reducers, mid-range water reducers, and workability retaining admixtures ensure the right level of slump is initially achieved and maintained until after consolidation processes occur.
Viscosity-modifying admixtures add cohesiveness for effective consolidation without segregation.
Rheology-modifying admixtures increase the lubricity of concrete, reducing stickiness and minimizing the energy required for consolidation.

Finishing Concrete

Concrete finishing can be impacted by timing, environmental conditions, and raw material characteristics. The following technologies can improve the finishing process and final appearance of concrete:
Mid-range water-reducing admixtures and high-range water-reducing admixtures reduce finishing effort and enhance surface appearance
Viscosity-modifying admixtures provide body and cohesiveness to overcome harsh or gap-graded aggregate effects on finishing.
Rheology-modifying admixtures provide lubricity for a reduced friction operation, resulting in a pleasing appearance.
Workability-retaining admixtures provide flexible degrees of slump retention without retardation, which improves the finishing window.
Accelerating and retarding admixtures define the “finishing window” by controlling setting time.