Fresh and hardened properties of self consolidating concrete

The mixtures were evaluated to determine several key responses that affect the performance of precast, prestressed concrete, including the filling ability, passing ability, filling capacity, stability, compressive strength, modulus of elasticity, flexural strength, autogenous shrinkage, drying shrinkage, and creep.

fresh and hardened properties of self consolidating concrete-8

Using the same tests as the first stage, the second stage varied the coarse-to-fine aggregate (C/F) ratio, coarse aggregate size, binder amount, and air content to optimize SCC containing metakaolin.

The third stage of the program was to study the effect of metakaolin and mixture design on the shear capacity and cracking behaviour on full-scale sec beams.

Wash water is frequently recycled using trucks equipped with devices that collect wash water and return it to the drum where it can be returned to the ready mixed concrete plant for recycling.

Extra concrete is often returned to the ready-mix plant where it is recycled or used to make jersey barriers or retaining wall blocks; or it can be washed to recycle the coarse aggregate.

However, when using a lower C/F ratio of 0.7, the HRWR demand increased for all mixtures, while all other design parameters reduced the HRWR demand.

Examining the mechanical properties, it was seen that using either a lower C/F ratio of 0.7 or increasing the binder content to 500 kg/m³ improved the compressive strength as well as the strength development, flexural strength, splitting tensile strength and the modulus of elasticity.

Ready mixed concrete has many environmental benefits during construction and for the life of the structure.

See associated sustainability solutions and technical briefs (right) for more detail. Concrete is ordered and placed as needed and does not need to be trimmed or cut after installation.

Special set retarding admixtures can be added to returned concrete to allow for storage and future use. Fly ash, slag cement, or silica fume can substitute partially for cement, and recycled aggregates can replace newly mined gravel.

Recycled content can contribute to LEED Credit M 4.

In addition, increasing the coarse aggregate size to 20 mm, increased the normalized shear strength and post diagonal cracking resistance in normal-strength sec beams, and showed no affect in high-strength sec beams.

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