Concrete Slab Tester

Concrete Slab Tester

The Concrete Slab Tester is designed for freeze-thaw testing of concrete specimens under controlled conditions, including freezing in air and thawing in air or water. The system complies with various European and international testing standards and features significantly increased cooling capacity for efficient temperature control.

In addition to concrete, the tester is suitable for evaluating natural stone and tile adhesives under freeze-thaw conditions. Optional features include an internet connection for remote access and data management, as well as a flooding mechanism for controlled water application during testing.

Test Procedure for the EU Standard Concrete Slab Test

The standard test requires four specimens prepared from four concrete cubes. After 21 days, a 50 mm thick specimen is cut from each cube perpendicular to the top surface. The test surface is positioned at the center of the cube to ensure consistent specimen preparation.

Each specimen measures 15 × 15 × 5 cm. After 25 days of concrete aging, a rubber sheet is bonded to all surfaces except the designated test surface. At 28 days, demineralized water with a depth of 3 mm is applied to the test surface and maintained for 72 hours.

After 31 days, all surfaces except the test surface are thermally insulated using 20 mm thick polystyrene foam. The demineralized water is then replaced with the specified freezing medium, and the test surface is covered with a polyethylene sheet.

Freeze-Thaw Cycle

One complete freeze-thaw cycle takes 24 hours. During each cycle, the temperature must remain above 0°C for at least 7 hours and no more than 9 hours.

The reference temperature is measured at the center of the test surface. Depending on the target temperature, the permitted variation can range from ±2.5 K to ±5 K, as illustrated in the corresponding test diagram.

Measuring Surface Scaling

Surface scaling is evaluated at defined intervals of 7, 14, 28, 42, and 56 days. At each measurement point, the scaled material is removed from the specimen surface using brushing, and its weight is measured.

This testing process provides quantitative data for assessing the freeze-thaw resistance and surface durability of concrete, natural stone, and tile adhesive materials.

Standards

The Slabtester is designed for freeze-thaw, scaling, thermal cycling, and durability testing in accordance with a broad range of European, international, Swiss, ASTM, ISO, and national standards. Depending on the selected test method, additional options or accessories may be required.

• SIA 262/1:2013-08; SN 505262/1:2013-08 — Concrete Structures – Supplementary specifications, Appendix C. Covers freeze-thaw resistance of concrete classes XF2(CH), XF3(CH), and XF4(CH).

• ASTM C666-03 (2008), Procedure B — Standard Test Method for Resistance of Concrete to Rapid Freezing and Thawing. Requires option C0108 for thawing in water.

• ASTM C672 / C672M-12 — Standard Test Method for Scaling Resistance of Concrete Surfaces Exposed to Deicing Chemicals.

• ASTM C1262-10 — Standard Test Method for Evaluating the Freeze-Thaw Durability of Dry-Cast Segmental Retaining Wall Units and Related Concrete Units.

• EN 1338 — Concrete Paving Blocks – Requirements and Test Methods; German version EN 1338:2003.

• EN 1339 — Concrete Paving Flags – Requirements and Test Methods.

• EN 1340 — Concrete Kerb Units – Requirements and Test Methods.

• EN 1348:2007-12-31 — Withdrawn and replaced by EN 12004-2:2017-05. Covers determination of tensile adhesion strength for cementitious tile adhesives. Requires option C0108 for thawing in water.

• EN 12004-2:2017-05 — Adhesives for Ceramic Tiles – Part 2: Test Methods. Requires option C0108 for thawing in water. Specimens are frozen to -15°C within 2 hours, held at this temperature for another 2 hours, and then thawed in +15°C water for 2 hours. After 25 cycles, tensile adhesion strength is measured.

• EN 1367-1:2007 — Tests for Thermal and Weathering Properties of Aggregates – Determination of Resistance to Freezing and Thawing. Requires option C0108 for thawing in water. The minimum air temperature is -22°C, while the temperature inside the can ranges from -15°C to -20°C for at least 4 hours. Cooling performance depends on the heat capacity and thermal conductivity of the specimen, water, and cans. Required cans are seamless stainless-steel containers with lids, Order Code C0665S.

• EN 1367-6:2008 — Tests for Thermal and Weathering Properties of Aggregates – Determination of Resistance to Freezing and Thawing in the Presence of Salt (NaCl). The flooding option C0108 is not required. Seamless stainless-steel cans with lids are required, Order Code C0665S.

• CEN/TS 12390-9:2006 — Testing Hardened Concrete – Freeze-Thaw Resistance – Scaling, Method 1: Reference Method.

• EN 12091:2013 — Thermal Insulating Products for Building Applications – Determination of Freeze-Thaw Resistance. Requires option C0108 for thawing in water.

• EN 12371 — Natural Stone Test Methods – Determination of Frost Resistance. Requires option C0108 for thawing in water.

• EN 12467:2012-12 — Fibre-Cement Flat Sheets – Product Specifications and Test Methods, Chapter 7.4. Requires option C0108 for thawing in water.

• EN 12808-3:2009-01 — Grouts for Tiles – Determination of Flexural and Compressive Strength. Requires option C0108 for thawing in water.

• ISO/DIS 13007-2.2 — Ceramic Tiles – Adhesives – Part 2: Test Methods for Adhesives. Requires option C0108 for thawing in water.

• EN 13383-2 — Armourstone – Part 2: Test Methods. Requires option C0108 for thawing in water.

• EN 13687-3:2002 — Products and Systems for the Protection and Repair of Concrete Structures – Test Methods – Determination of Thermal Compatibility – Thermal Cycling Without De-Icing Salt Impact. Requires option C0108 for thawing in water. The inner vessel can accommodate up to four specimens measuring 30 × 30 × 5 cm, with a 10 cm spacing between specimens when positioned vertically.

• EN 14891:2013-07 — Liquid-Applied Water-Impermeable Products for Use Beneath Ceramic Tiling Bonded with Adhesives – Requirements, Test Methods, Evaluation of Conformity, Classification, and Designation. Requires option C0108 for thawing in water.

• CEN/TR 15177:2006 — Testing the Freeze-Thaw Resistance of Concrete – Internal Structural Damage. Requires an instrument for measuring internal structural damage, such as the Vikasonic. When using beams measuring 100 × 100 × 400 mm, option C0108 is also required for thawing in water.

• DIN V 18004 — Use of Building Products in Construction Works – Test Methods for Aggregates according to DIN V 20000-103 and DIN V 20000-104.

• ONR 22303:2010 09 01 — Test Methods for Concrete – National Application of Testing Standards for Concrete and Its Source Materials.

• EN 772-22:2019 — Methods of Test for Masonry Units – Part 22: Determination of Freeze/Thaw Resistance of Clay Masonry Units. Supports specimens up to 58 × 58 cm² and requires options C0108 and C01085.

Concrete Slab Tester Features

The Concrete Slab Tester features a temperature- and time-controlled refrigeration and heating system supported by three fans for efficient air circulation throughout the test chamber. The inner and outer surfaces are constructed from stainless steel, providing a durable and easy-to-maintain testing environment.

The system uses R290 refrigerant, an environmentally friendly refrigerant with a very low Global Warming Potential (GWP). This helps provide efficient temperature control while reducing the environmental impact of the refrigeration system.

Programmable Freeze-Thaw Testing

The testing chamber supports controlled freezing and thawing of specimens with up to 8 freely programmable temperature profiles. Common testing standards, including EN 1340 and EN 12390-9, are available as pre-set profiles and can be adjusted according to testing requirements.

Two temperature sensors are included and can be positioned at different locations inside the chamber. For example, one sensor can monitor the specimen surface temperature, while the other can measure the temperature at the bottom of the specimen.

Graphical Touchscreen Display

A graphical touchscreen display provides a clear overview of the test conditions and shows:

• Set temperature

• Specimen temperature

• Chamber air temperature

• Cooling unit temperature

All temperature measurements are recorded internally, allowing test data to be transferred to a USB memory stick for storage, analysis, and documentation.

Network Connectivity and Remote Control

The Concrete Slab Tester includes a network interface for convenient remote monitoring and control through a local network. No additional software is required. Users can access the Slabtester by opening a standard web browser and entering the device's network address.

Temperature profiles can also be configured from a PC, while recorded temperature data can be viewed as graphical charts directly in the browser. Test data can be exported to Microsoft Excel for local backup and further analysis.

Local Data Storage

Test data is stored locally on the system, allowing users to manage and retain measurement records without requiring external internet access. This setup supports convenient data management while keeping testing information within the local system.

Included Accessories

The Concrete Slab Tester is supplied with:

• 4 shelves

• Electronic controller

• Network cable

• USB memory stick

• User manual

Optional Features for Concrete Slab Tester

Flooding Option

The Flooding Option C0108 adds controlled water flooding for freeze-thaw testing. A removable stainless-steel inner container, measuring approximately 50 × 60 × 48 cm (W × D × H), is installed inside the test chamber. A second container positioned outside the chamber houses the pump and heating unit.

During the freezing stage, the inner container remains empty. During thawing, temperature-controlled water is pumped from the external container into the inner vessel, where it remains throughout the thawing period. Once thawing is complete, the water is drained back into the external container.

The flooding and draining times can be freely programmed, allowing the system to accommodate different freeze-thaw test procedures.

With this option, the Slabtester is suitable for testing natural stone according to EN 12371, aggregates according to EN 1367-1, tile adhesives according to EN 1348:2007, and other applicable standards listed above.

Circulating Flooding Option

The Circulating Flooding Option provides functionality similar to the standard Flooding Option C0108, while using slightly larger inner and outer vessels.

The inner vessel features an overflow system and is filled from the bottom. Water exits through the overflow positioned below the upper edge of the vessel, maintaining controlled water circulation during thawing.

During the thawing stage, the pump operates continuously. Once thawing is complete, the pump stops and the water flows from the inner vessel back into the outer container.

The inner vessel includes a convenient drawer mechanism that simplifies specimen loading and removal, making it easier to prepare and manage freeze-thaw tests.

Clay Masonry Unit Testing Option — EN 772-22:2018

An additional option is available for freeze-thaw resistance testing of clay masonry units according to EN 772-22:2018.

This configuration provides automatic water spraying at specified intervals in accordance with the test procedure. The spraying intervals can be freely programmed to match the required testing sequence.

The maximum test wall size, including the frame, is 58 × 58 cm. This configuration also requires the Natural Stone Option (C0108) and includes a 6 bar air pressure compressor.

Heat Flow Meter for EN 772-22:2018 Calibration

A Heat Flow Meter is available for calibrating freeze-thaw tests for clay masonry units in accordance with EN 772-22:2018.

The heat flow meter is an insulated device designed to extract heat from the central section of the surface exposed during testing. The central area has a matte-black surface and is designed to remove sufficient heat so that, when the surrounding air temperature reaches -15°C, the center of the plate can be maintained at 0°C.

The system allows the average heat extraction rate to be measured, supporting calibration and verification of the freeze-thaw test conditions for clay masonry units.

Concrete Slab Tester Technical Specifications