Concrete setting retardation
BEVETOL-VZ Concrete set retarder
RETADOL Concrete set retarder – Plasticizer
I. NATURE OF THE PROBLEM – REQUIREMENTS
Concreting applications that require transportation of ready-mixed concrete over long distances, where concreting is done at high temperatures, or where avoiding of construction joints is desirable, require suitable measures for achieving retardation of concrete’s setting.
The addition of BEVETOL-VZ (ASTM C-494 type B. Certified with the CE marking as set retarding concrete admixture according to EN 934-2:T8, certificate number: 0906-CPD-02412007) or RETADOL (ASTM C-494 type D. Certified with the CE marking as set retarding – water reducing – concrete plasticizing admixture according to EN 934-2:T10, certificate number: 0906-CPD-02412007) in the concrete, retards its setting and plasticizes it.
BEVETOL-VZ and RETADOL offer the following advantages:
- Ability of transporting concrete over long distances.
- Increased concrete strength due to its plasticizing action (RETADOL).
- Avoiding of construction joints even if extended breaks in concreting occur.
- When used at the right dosage, they do not retard the development of initial concrete’s strength and therefore they do not delay the removal of form works.
- Improve pumpability of the concrete.
- Facilitate compression of the concrete.
- Prevent segregation of concrete and the phenomenon of “sweating”.
- Reduce cracking and shrinkage.
- Do not contain chlorides or other corrosive ingredients.
- Do not have air-entraining action.
- Are compatible with all types of Portland cement.
BEVETOL-VZ and RETADOL can be used wherever retardation of concrete setting is required, such as at transportation of ready-mixed concrete over long distances, concreting at high temperatures, or in order to avoid joints from interruptions in work, etc. At the same time, it improves the properties of the concrete and its workability.
BEVETOL-VZ and RETADOL should be added in the concrete mixing water in the proportion of:
- BEVETOL-VZ : 0,2-0,4% by cement weight, according to the desired retardation time.
- RETADOL : 0,2-0,3% by cement weight, according to the desired retardation time.
The exact dosage should be determined after a trial test in practice.
The plasticizing properties of BEVETOL-VZ and RETADOL must be taken into account when calculating the amount of mixing water required.
- Overdose may adversely affect the final strength of the concrete.