Product description

STEIN TEC® Drain Concrete DBT 08 is an exclusively by STEIN TEC® developed work dry concrete for bonded base courses. With its properties it meets resp. surpasses the requirements of the FGSV Merkblatt für Dränbetonschichten (DBT) Nr. 827 (=FGSV bulletin about drain concrete layers Nr. 827). STEIN TEC® Drain Concrete DBT 08 will be delivered in the silo with mixing device, at an amount of more than 15 to. It features controlled, considerably reduced shrinkage, quick strength development and considerably higher strength values, compared to drain concrete according to the FGSV bulletin.

The shrinking properties of STEIN TEC® Drain Concrete DBT 08 are optimally adapted to STEIN TEC® bedding and jointing mortars. Under appropriate conditions, it is possible to pave on base courses made of STEIN TEC® Drain Concrete DBT 08 after 24 hours already. A significant advantage if – as common these days – a quick construction progress is required.

Furthermore, notching of the drain concrete layer at intervals of 5 m maximum (according to FGSV bulletin about drain concrete layers) is not necessary. Therefore, the overlaying expansion joints in the bedding and the surface are omitted. The making and the maintenance of expansion joints is very expensive. Paved as well as slabbed surfaces are visually and aesthetically significantly more appealing without expansion joints.

Using STEIN TEC® Drain Concrete DBT 08 for the base course, so enables to create, in combination with STEIN TEC® bedding and jointing mortar, heavily used and very appealing pavements and slabbed surfaces. The complete system is reinforced in that way, that also traffic loads up to construction classification “SV” according to RStO 01 (=heavy traffic) can be durably borne. At professional processing an evenly high adhesive bond with STEIN TEC® bedding mortars is achieved. To obtain detailed information, please contact our technology department.

The minimum thickness of a base course made of STEIN TEC® Drain Concrete DBT 08, when compacted, is 15 cm, the maximum thickness for one-layer construction is 25 cm. For bigger thicknesses the drain concrete has to be multi-layer processed with intermediate compaction. Respective regulations and generally accepted codes of practice, especially the FGSV bulletin about drain concrete layers and RStO, must be complied with. For traffic areas where heavy traffic is expected, the requirements in terms of design and sustainability should be set for the panel 3 (Construction Classification III according RStO 01) or Load Classification 3.2 according RStO 12.

For building-in the usual principles for compaction and after-treatment must be complied with. STEIN TEC® Drain Concrete DBT 08 can be built in by a road finishing machine.


  • shrinkage-reduced
  • low-stress
  • accelerated hardening
  • early loadable and pavable
  • hhigh compressive strength
  • high adhesive tensile strength
  • high water-permeability
  • frost-resistant
  • very good processability
  • processable by road finishing machines

Important information

To avoid soiling of the hollow-spaces within the drain concrete base course, the drain concrete base course must be not used by site-traffic. If site-traffic is inevitable, this will be only possible after sufficient hardening of the drain concrete base course and under adequate protection against soiling.


STEIN TEC® Drain Concrete DBT 08 shall be mixed in earth-moist texture (see “Snow ball test”) in the horizontal flow-mixer mounted to the silo and shall be built-in under approx. 25 per cent of static compaction (required gross density of hardened concrete 1.850 kg/m³, cp. table ”Technical specifications”). It is possible to build-in STEIN TEC® Drain Concrete DBT 08 by finishers. The completed layer needs to be after-treated. For further information please see Technical bulletin for STEIN TEC® Drain Concrete DBT 08.


Mixing of STEIN TEC® Drain Concrete DBT 08 in earth-moist texture.

Snow ball test

“Snow ball” to test earth-moist texture.


Processing / compacting of the drain concrete base course by a static roller.


Compacting must be made statically – compaction by vibrations would affect the water permeability.

Initial use

Normally, on STEIN TEC® Drain Concrete DBT 08 can be paved 24 hours after its making. At an ambient temperature of 20 °C, the drain concrete attains strength of > 5 N/mm² after that time. If the ambient temperature is lower, longer setting and hardening time must be expected.

Technical specification

Binding agent base hydraulically binding specialty cements
Minimum processing temperature 5° C, night-frost free
Processing time approx. 1,5 hours at 20° C
Requirements approx. 19 kg dry mortar / cm / m2
Built-in thickness 15 cm in compacted condition
Built-in thickness (single-layer) 25 cm in compacted condition
Compressive strength after 1 day (20° C) * > 5 N/mm2
Compressive strength after 7 days (20° C) * > 20 N/mm2
Compressive strength after 28 days (20° C) * > 25 N/mm2
Adhesive tensile strength1) > 1,5 N/mm2
Gross density of hardened mortar 1.850 kg/m3
E-module < 15.000 N/mm2
Water permeability > kf = 1 x 10-4 m/sec
Theoretical build-in rate Mixing rate 5 to 6 m3/h/silo. The actual build-in rate depends on the site conditions
All values determined on the basis of lab-body blocks in build-in density at 20° C at the specified testing age resp. after 28 days.
1) Determination of adhesive tensile strength on slab base-body according to DAfStb-guideline “Schutz und Instandsetzung von Betonbauteilen, Teil 4 (= Protection and reinstatement work of concrete elements, part 4) with “Haftfix”.
Subject to technical modifications.
Important information
Suitability for storage approx. 6 months in the silo.
* The decrease of temperature down to 10° C doubles the needed time for hardening. At the decrease down to 5° C it will be quadrupled.

You can download the Technical bulletin here.