Slab Tester - Freeze Thaw Tester

Slab Tester - Freeze Thaw Tester

EN 1340, EN 1339, EN 1338, EN 1367-1, EN ISO 12390-9, DIN V 18004, EN 12371

Qualitest's Slab Tester is a temperature and time controlled frost-thaw test system. It allows freezing and thawing of concrete specimen according to EN 12390-9 and EN 1339 EN 1367-1, DIN V 18004 and 1340:2002. The Slab Tester is made of stainless steel, standard delivery includes: Slab Test set-up, 4 shelves, electronic controller, manual.

Qualitest Slab Freeze Thaw Tester is designed to accommodate specimen testing for freezing in air and thawing in air or water. The tester conforms to several European and international standards. The Slab tester is not only used for concrete testing but also for testing of natural stones and tile-glues. Optional Data logger / Internet connection and a flooding mechanism are also available.

Test Procedure for the EU Standard Concrete Slab-Test

The test requires four specimens obtained from four cubes. After 21 days a 50mm thick specimen is cut from each test cube. The cut is perpendicular to the top surface so that the saw cut for the test surface is located in the center of the cube. The specimens size is 15x15x5 cm.

When the concrete is 25 days old a rubber sheet is glued to all surfaces except the test surface. Place a string of glue around the test surface in the corner between the concrete and the rubber. After 28 a 3mm layer of de-mineralized water is poured on the top surface and maintained for 72h. After 31 days all surfaces except the test surface are thermally insulated with 20mm thick polystyrene foam. Then the de-mineralized water is replaced by a freezing medium and the test surface is covered with a polyethylene sheet.

One frost thaw cycle is run in 24 hours. The temperature shall exceed 0°C during each cycle for at least 7h but not more than 9h.

The reference temperature is measured in the middle of the test surface and may deviate, as shown in the tabular below, between +/-2.5 K and +/- 5 K from the target temperature.

Standards

The Slab tester is suitable for tests according to the following standards

CEN/TS 12390-9:2006 (former prEN 12390-9)
( Testing hardened concrete - Freeze-thaw resistance - Scaling)
EN 1340
( Concrete kerb units - Requirements and test methods)
EN 1339
(Concrete paving flags - Requirements and test methods)
EN 1338
( Concrete paving blocks - Requirements and test methods; German version EN 1338:2003)
EN 1367-1
Tests for thermal and weathering properties of aggregates - Determination of resistance to freezing and thawing
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
EN 12371
Natural stone test methods - Determination of frost resistance
EN 1348
EN 1348: Adhesives for tiles - Determination of tensile adhesion strength for cementitious adhesives.

Additional Features

Programming Tool, Internet Interface and Data Logger

This feature makes the Slab Tester much more sophisticated. Up to 8 user defined programs for the temperature over time relation can be added. Two add. temperature measuring devices for measuring the temperature in the freezing medium on the test surface and in the air. The data from the last temperature cycles are recorded and can be downloaded from any PC by a Ethernet TCP/IP interface. The Slab Tester can be operated by an internet browser from any PC in your intranet. Up to 8 user defined temperature programs may be created. A data acquisition module stores the temperature data of the last 4 weeks. The temperature curve of the last 24h may be plotted on the color touch screen. Including: TCP/IP interface, add.temperature sensor, color touch screen, software, CF-card, CF-card-reader, user manual.

Flooding Option

A stainless steel vessel (ca. 60x50x40cm) is mounted (removable) inside the test chamber. A 2nd vessel is outside of the test chamber. In this outside vessel a pump and a heating unit is mounted. During freezing the inner vessel is empty. For thawing, water from the outside vessel, with an integrated heating unit, is pumped into the inner vessel. Time for flooding and emptying is freely programmable. This option requires the feature "Programming Tool C1041". This feature for the Slab Tester is for testing natural stones according to EN 12371, aggregates according to EN 1367-1 and tile-glue according to EN 1348:2006.