2. 2.3. Procedures Used for Product Evaluation
• The Single Ring Infiltrometer Test (SRIT)
- was developed by the American Society for Testing and Materials, now ASTM International to measure infiltration in the field.
The method involves the following steps.
a. The base of a 300 mm diameter ring is sealed to the surface of the porous pavers, generally with builder’s putty or a similar filler.
b. The surface to be tested is first pre-wetted before any measurements are taken by pouring 3.6 kg (3.6 litres) of water into the ring at a rate sufficient
to maintain a constant head between two marked lines (between 10 and 15 mm from the base). The time taken for the water to infiltrate fully
through the surface (from the time the water is first poured to the time it is no longer visible on the surface) is recorded to the nearest 0.1 seconds.
c. The actual SRIT test is then performed by repeating step (b) above using 3.6 kg of water if the pre-wetting time duration is less than or equal to 30
s. If the pre-wetting time is exceeded, the test is repeated using 18 kg (18L) of water. The time for the water to disappear (T) through the pavers is
recorded for the applicable mass of water (M).
d. The infiltration rate can be calculated using:
I = KM/D2T
3. 2.3. Procedures Used for Product Evaluation
• The Stormwater Infiltration Field Test (SWIFT)
- it is a simple, quick, and inexpensive field test using readily available equipment as an alternative
method for measuring the infiltration rate of PICPs. Lucke et al. 2019, showed that there is a correlation between
the results of the SWIFT and SRIT tests that is evident when results collected using these two methods are
compared graphically. SWIFT uses a 12-20 L bucket with a 40 mm hole cut into its base.
The test involves the following steps:
a. The bucket is placed over the surface of the pavers to be tested ensuring its drainage hole is located directly
above the center of a paver.
b. The bucket is filled with 6 L of water with a plug inserted in the bucket drain hole.
c. The plug is removed, and water is allowed to flow out of the bucket and onto the paving surface.
d. The number of individual pavers that are fully wetted is counted and recorded.
