Concretum Q-FLASH 2/20 · Concretum® Q-FLASH 2/20 Rapid-hardening concrete 1. Description 1.1. Product Concretum® Q-FLASH 2/20 is a rapid-hardening concrete comprising rapid-hardening

Technical data sheet (TDS)

Concretum® Q-FLASH 2/20 Rapid-hardening concrete

1. Description

1.1. Product

Concretum® Q-FLASH 2/20 is a rapid-hardening concrete comprising rapid-hardening cement Con-cretum® Q-FLASH cem 50 (P), Portland cement CEM I 52.5 R, superplasticiser Concretum® Q-FLASH sp (L), retarder Concretum® Q-FLASH ret (L), aggregate and water. This rapid-hardening concrete is produced as in-situ concrete or as ready mixed concrete in stationary or mobile concrete plants.

1.2. Application

Concretum® Q-FLASH 2/20 is a rapid-hardening concrete that is used for large-scale reconstruction of concrete pavements in transport surface construction. The rapid-hardening concrete is used par-ticularly on motorways and airport pavements whenever reconstruction work must not disrupt road and air traffic. The very rapid hardening and drying of Concretum® Q- FLASH 2/20 allows this recon-struction work while in operation.

1.3. Advantages

Despite the rapid hardening, Concretum® Q-FLASH 2/20 remains workable for an open time of 60-120 minutes. It has a very low cracking risk and a high durability. The rapid hardening concrete can be poured both by machine with slipform pavers and also manually. It is also characterised by the follow-ing properties:

• Very rapid hardening and drying

• Simple handling

• Long open time

• Machine (slipform paver) and manually pourable

• Very good compatibility with existing concrete surfaces

• Low temperature dependency

Technical Data Sheet – Concretum® Q-FLASH 2/20 Seite 2

Concretum AG, Technoparkstrasse 1, CH-8005 Zürich, +41 44 445 13 46 [email protected], www.concretum.com

• Very high durability: low shrinkage, low heat of hydration

• No impact from moisture on areas adjoining the construction

• Purely cementitious: does not contain either polymers or epoxy or methacrylate resins

2. Concrete properties

The rapid-hardening concrete Concretum® Q-FLASH 2/20 has the following properties:

• Open time(*): Adjustable between 60 and 120 minutes

• Compressive strength fc(*): ~ 20 N/mm2 approx. 60 to 90 minutes after end of open time

60 N/ mm2 after 28 days

• Flexural strength fb(*): ~ 4.5 N/mm2 approx. 60 to 90 minutes after end of open time

7.5 N/mm2 after 28 days

• Indirect tensile strength ft(*): ~ 3.0 N/mm2 approx. 60 to 90 minutes after end of open time

4.5 N/mm2 after 28 days

• Moisture < 4 CM-%: Approx. 3 hours after the end of open time

• Exposure classes: XC4, XD3, XF4

• Strength class: C50/60

• Degree of compactibility: consistency classes C0-C2 according to EN 206-1

• Maximum aggregate size: 8 to 32 mm

• Aggregate: Rounded / crushed

• Alkali-Aggregate-Reaction: Resistant

• Fresh concrete temperature: 5 - 30 °C

• Shrinkage εSH 91d: Approx. 0.20‰

• Heat of hydration: Approx. 210 J/g (corresponds to low heat cement)

(*) Guide values, the exact values depend on the composition of the concrete, the local aggregate and the marginal conditions (weather, component thickness, etc.).

3. Feature

Just like standard concretes, the rapid-hardening concrete Concretum® Q-FLASH 2/20 comprises cements, admixtures, aggregates and water. Concretum AG as supplier of the rapid-hardening ce-ments and admixtures is only responsible for their properties. The concrete manufacturers (either a ready mixed concrete company or a construction company with its own concrete plant) are respon-sible for the quality of the rapid-hardening concrete that is produced with the above components. All the information in this datasheet relating to the concrete is therefore indicative. It is based on values



gained from experience and Concretum helps the named project participants to achieve the con-crete properties.

4. Components and their properties

4.1. Cements: Concretum® Q-FLASH cem 50 (P) / cem 100 (P) and Portland cement

Two versions of added cement are possible. See also 'Illustration of the components' at the end of the 'Components' section.

• Large concrete amounts, if the concrete plant has two cement silos:

Rapid-hardening cement Concretum® Q-FLASH cem 50 (P) and Portland cement CEM I 52.5 R in a ratio of 1:1 (compatibility tested by Concretum)

• Small/medium aggregate quantities, if the concrete plant only has one cement silo:

Rapid-hardening cement Concretum® Q-FLASH cem 100 (P). This contains a compatible Portland cement CEM I 52.5 R in the right quantity.

Concretum® Q-FLASH cem 50 (P) and Concretum® Q-FLASH cem 100 (P) are equivalent in terms of their physical properties. These are as follows:

Effect: Concretum® Q-FLASH cem 50 (P) and cem 100 (P) cause extremely rapid hardening and drying, as well as low shrinkage and heat of hy-dration of the concrete.

Colour/Consistency: Cement-grey powder

Delivery form: 25 to silo delivery (loose)

Shelf life: If stored according to the storage conditions, 6 months from produc-tion date.

Storage conditions: Store in closed cement silos, dry and protected from the weather. Residue-free cleaning must be ensured before and after use of the product in a cement container (e.g. silo). This also applies to smaller quantities, which may remain as residue in the case of careless clean-ing of silos or similar cement containers.

Chemical basis: Purely mineral, hydraulic binding agent

Consistency: Homogeneous

Bulk density: Approx. 1.2 – 1.9 kg/l

Specific density: Approx. 3.0 kg/l

Water-soluble chloride content: < 0.1 M-%



4.2. Superplasticiser: Concretum® Q-FLASH sp (L)

Effect: Concretum® Q-FLASH sp (L) fulfils the requirements of concrete ad-mixtures of effectiveness group FM according to EN 934-2. In Combi-nation with Concretum® Q-FLASH cem 50 (P) / cem 100 (P) and Con-cretum® Q FLASH ret (L), Concretum® Q-FLASH sp (L) causes an ex-tremely rapid hardening and drying, as well as low shrinkage defor-mation and heat of hydration of the concrete.

Colour/Consistency: Brown liquid

Delivery form: 10 kg canister, 200 kg barrel, 1,000 kg IBC container


Storage conditions: In unopened original packaging without direct sunlight between +5 and +30 °C.

Chemical basis: Modified polymer in water

Specific density: 1.135 +/- 0.03 kg/l

ph value: 6.0 – 7.5

Alkali content: < 3.0 M-% (Na2O equivalent)


Usual solids content: 36 +/- 2 M-%

Viscosity: 50 to 100 mPa s at 20 °C


4.3. Retarder: Concretum® Q-FLASH ret (L)

Effect: Concretum® Q-FLASH ret (L) is a retarder that has been specially de-veloped for the rapid-hardening cement Concretum® Q-FLASH cem 50 (P) / cem 100 (P). It may only be used with these cements. In com-bination with these and with the superplasticiser Concretum® Q-FLASH sp (L), Concretum® Q- FLASH ret (L) causes an extremely rap-id hardening and drying as well as low shrinkage deformation and heat of hydration of the concrete.

Colour/Consistency: Colourless liquid

Delivery: 10 kg canister, 200 kg barrel, 1,000 kg IBC container


Storage conditions: In unopened original packaging without direct sunlight between +5 and +30 °C.

Chemical basis: Watery solution (acid)

Specific density: 1.23 +/- 0.05 kg/l

ph value: 0.5 – 2



Alkali content: < 3.0 M-% (Na2O equivalent)


Usual solids content: 50 +/- 2 M-%

Viscosity: 10 to 50 mPa s at 20 °C


4.4. Aggregate

Both rounded and crushed aggregate can be used. It must fulfil the requirements of standard EN 206. The intrinsic moisture content of the aggregate must be known to 0.1%.

4.5. Water

Only drinking water (no recycling or residual water) may be used for production of Concretum® Q-FLASH 2/20.

4.6. Illustration of the components

The following images show the components of the rapid-hardening concrete Concretum® Q-FLASH 2/20. The first version (fig. 1) contains the rapid-hardening cement Concretum® Q-FLASH cem 50 (P) mixed with local Portland cement while the second version (fig. 2) uses the rapid-hardening cement Concretum® Q-FLASH cem 100 (P) as the sole binder, which already contains a compatible Portland cement.

Figure 1: Components of the rapid-hardening concrete Concretum® Q-FLASH 2/20 when using the rapid-hardening

cement Concretum® Q-FLASH cem 50 (P) in combination with local Portland cement.



Figure 2: Components of the rapid-hardening concrete Concretum® Q-FLASH 2/20 when using the rapid-hardening

cement Concretum® Q-FLASH cem 100 (P).

5. Working instructions

5.1. Application

To produce the rapid-hardening concrete Concretum® Q-FLASH 2/20, the binder Concretum® Q- FLASH cem 100 (P) or Concretum® Q-FLASH cem 50 (P) plus compatible Portland cement may only be used in combination with the retarder Concretum® Q-FLASH ret (L) and the superplasticiser Con-cretum® Q-FLASH sp (L).

5.2. Concrete composition

5.2.1. Binder (rapid-hardening cement + Portland cement)

The total dose of the binding agent is typically 360 to 450 kg/m3. The binder comprises either the rapid-hardening cement Concretum® Q-FLASH cem 50 (P) mixed with a compatible Portland cement CEM I 52.5 R in the approx. ratio 1:1 or only rapid-hardening cement Concretum® Q- FLASH cem 100 (P).

5.2.2. Superplasticiser: Concretum® Q-FLASH sp (L)

Based on the total binder weight, the dose is approx. 0.2% to 3.0%.

5.2.3. Retarder: Concretum® Q-FLASH ret (L)

Based on the total binder weight, the dose is approx. 0.5% to 2.0%.

5.2.4. Aggregates

The dose typically amounts to 1,800 to 2,000 kg/m3 and is calculated using the mix design equation. The proportions of the individual aggregate sizes must be specified in advance within the framework of a plant set-up. They typically correspond to the grading curves usually applied. Both rounded and crushed aggregate can be used. As with standard concretes, the intrinsic moisture of the aggregate has to be offset against the water content (but not the core moisture).



5.2.5. Mixing water (exclusively drinking water)

Based on the total binder weight, the water dosage is approx. 30% to 36% (water to cement ratio: 0.30 - 0.36). The moisture content of the aggregates has to be offset against the total water quantity. The water to cement ratio must be complied with because the wet and solid concrete properties criti-cally depend on this.

5.2.6. General information

It is recommended that the composition of the concrete is specified in cooperation with Concretum in a so-called plant set-up. A plant set-up includes preliminary tests in the form of test mixings, the check of relevant wet and solid concrete properties, and a test of the compatibility of the respective aggregates used.

The rapid-hardening concrete Concretum® Q-FLASH 2/20 must be produced exclusively with the components named in this data sheet. In exceptional cases, the compatibility with other components (admixtures, additives, etc.) can be reviewed as part of the plant set-up.

5.3. Mixing

The rapid-hardening concrete Concretum® Q-FLASH 2/20 has to be produced exclusively in concrete plants, which produce concrete according to the standard EN 206.

All the binder is added before the aggregate is mixed. Then the admixtures Concretum® Q-FLASH sp (L) and Concretum® Q-FLASH ret (L) are added to the mix or are added simultaneously to the mixer. For the optimum use of the strong water reduction, a wet mixing time of 120 - 180 seconds is rec-ommended. The fine water addition is started after 2/3 of the wet mixing time at the earliest in order to prevent excess water in the concrete. The suerplasticiser Concretum® Q-FLASH sp (L) has a compar-atively slow effect.

5.4. Pouring

The rapid-hardening concrete Concretum® Q-FLASH 2/20 can be placed by slipform paver or by hand. The requirements for the machinery and equipment do not differ significantly from those used when pouring standard concretes.

The low heat of hydration of the rapid-hardening concrete also allows very bulky structures with con-struction thicknesses of up to 2.0 m to be produced in one step.

5.5. Post-treatment

In order to ensure an optimum surface quality, a curing compound must be sprayed onto the con-crete surface immediately after pouring. The minimum quantity is stated in the product data sheet of the post-treatment agent. After spraying, the surface has to be covered with insulation mats to pre-vent the surface cooling. The insulation mats may not be removed for at least one hour after the start of setting.

5.6. Further information

Unless stated explicitly in the technical data sheet, the general rules of good concrete production ac-cording to the applicable standards and other regulations in respect of measures for ensuring the



optimum working and post-treatment of concrete shall always apply to the production and working of Concretum® Q-FLASH 2/20.

6. Measurement values

All measurement values stated in this technical datasheet are based on internal laboratory tests by Concretum AG. The effective values may deviate from the stated measurement values due to external circumstances which Concretum AG cannot control.

7. Country-specific data

The data and measurement values of the Concretum AG products may vary depending on the coun-try of use. The respective local technical data sheets apply. Upon request, Concretum AG will provide information about which data and measurement values apply in the individual countries.

8. Important safety information

When using rapid-hardening concrete Concretum® Q-FLASH 2/20 and the products named in this data sheet, the same recommendations apply in respect of handling and personal safety equipment as for standard cements, concretes and admixtures.

In particular, the following is emphasised here:

• The rapid-hardening cements Concretum® Q-FLASH cem 50 (P) and cem 100 (P) are alkalis and are irritants.

• The admixture Concretum Q-FLASH ret (L) is an acid and requires safety goggles, gloves and long clothing (no bare skin) to be worn.

For detailed information, please consult the current safety data sheets for the components Concre-tum® Q-FLASH cem 50 (P) / cem 100 ( P), Concretum® Q-FLASH sp (L) and Concretum® Q- FLASH ret (L) at www.concretum.com.

9. Documentation of defects

Concretum AG products have the specific properties conclusively named in this technical data sheet.

To safeguard the quality of the product properties, Concretum AG retains a sample batch of each production batch for a period of 24 months.

If Concretum AG products are reported by a client as defective, the product properties are checked exclusively by testing the corresponding batch sample using an internal testing procedure.



10. Legal information

This datasheet forms a component of any contract between Concretum AG and the customer. The product properties are described in full in the section 'Components and their properties'. The prod-ucts must be used according to the provisions of Concretum AG and this datasheet.

Version: 10.05.2017

Documents

Concretum Q-FLASH 2/20 · Concretum® Q-FLASH 2/20 Rapid-hardening concrete 1. Description 1.1. Product Concretum® Q-FLASH 2/20 is a rapid-hardening concrete comprising rapid-hardening