Washout Test Process
Field quality is assurance is critical to the success of a project. The amount of Helix® reinforcement added must be verified either by inspection or by testing.
UES ER 279 (Helix Steel Evaluation Report) requires Washout Testing in accordance with CSA A23.2-16C for certain types of applications. The following are instructions on how to complete this testing and interpret the data in accordance with the requirements of the standards. This document contains an outline of the test CSA Washout Test procedure to familiarize the user with the process. The actual procedure available from the CSA should always be used when testing.
A sample of concrete of known volume is washed. Helix® reinforcement is recuperated using a magnet dried and weighed.
- A scale accurate to 0.05 kg (1 oz)
- A tamping rod
- An air meter bucket of known volume
- A steel strike off bar
- Strainer or wet sieve box
- Rubber Mallet
- Glass or Plate (larger than diameter of bucket)
Samples of concrete shall be obtained at around 25%, 50%, and 75% points of discharge. Each sample shall be identified and tested separately.
- Fill the air bucket in three layers, rodding each 25 times, tapping side at least 10 times after each layer until no large air bubbles surface.
- Strike of the top of the bucket with the strike-off bar and clean the exterior of the bucket.
- Measure the net mass of the bucket (mass of bucket full of concrete minus empty bucket) and compute the density of the concrete (net mass / bucket volume)
- Wash the contents of the bucket out over a strainer or sieve fine enough to capture the Helix® reinforcement to remove the fine aggregates and cement.
- Use a magnet to separate the Helix® reinforcement from the remaining aggregates.
- If immediate/field results are needed towel dry the Helix® reinforcement and weigh them. Record mass to nearest gram (0.5 oz). Retain the sample for oven drying.
- Oven-dry the Helix® reinforcement at 110 C (230 F) for 16 hours and weigh them. Record mass to nearest gram (0.5 oz)
Calculations: Site Batching Into Mix Trucks (Loaded Truck at Construction Site)
The dosage rate of Helix® reinforcement in kilograms per cubic meter (lb per cubic yard) of concrete in the individual samples shall be calculated by dividing the dry mass of the fibres in kilograms (lb) by the volume of the concrete sample in cubic meters (cubic yards). The reported dosage shall be the average of the three samples.
Verification Dosage Complies with ER 279
Given the random nature of Helix® reinforcement and variations in consistency of concrete there is a factor of safety built into all Helix designs to assure enough Helix® reinforcement is provided to meet the design criteria. The reported to dosage computed above must be equal to or greater than the minimums presented in Appendix A of the evaluation report.