ISAT apparatus is used to assess the surface absorption characteristics of concrete.

About the apparatus

Initial Surface Absorption Test (ISAT) Apparatus

The rate of flow of water per unit area into a concrete surface when subjected to a constant head of 200mm is measured.

The unit consists of a capillary tube mounted on a scale, a water reservoir & connecting tubes.

Easy to use, mounted on a stand

The cell is manufactured from clear acrylic to allow observation of the water level and ensure the complete renewal of air.

Method

Before use the capillary tube is calibrated to determine the area of the cross section.

The area of the cell is measured and the scale factor for the cell/tube combination is determined.

0.01 ml/m3/sec = 6.10-4 AreaCell length mm of tubing
Areacapillary

The cell is clamped to the test surface so as to ensure an even pressure and good seal around the perimeter.

For each set of readings the reservoir is closed off and the flow distance along the capillary is measured for 5 seconds.

The number of scale units determines the observation period.

Number of Scale Units moved in 5 seconds Period during which movement is recorded

Less than 3 2 minutes

3-9 1 minute

10-30 30 seconds

More than 30 Record initial surface absorption as more than 3.60ml/m5/sec