Table of Contents

fresh concrete sample

To ensure that it is representative of the entire truckload, a standard sample consists of scoopfuls taken from different parts of the batch and collected in buckets.

The scoopfull must be taken through the moving stream, as the load is discharged, the entire width and depth (not just the top portion) is sampled. The size of the sample taken should be 1.5 times the estimated quantity required for the test.

The whole operation of fresh concrete sampling can be divided into three steps as given below.

Phase-1 (collection of samples in increments)
Step-2 (Composite Sample Preparation)
Step-3 (Recording Sample Information)

Phase-1 (Collection of samples in increments)

Fresh concrete samples can be collected from the mixer at the time of discharge or after the concrete is discharged on site.

When taking samples from the mixer, then divide the batch into different parts and take sample increments from those parts. Avoid taking samples of the first and last part.

If it is a continuous mixer, one batch is considered to be discharging concrete over the course of one minute. So in the case of a continuous mixer, take sample increments at equal intervals at the same intervals. For example, if you want to take 3 increments, then take increments after 15 seconds, 30 seconds and 45 seconds. If more increment is to be taken, then the time interval will have to be selected accordingly.

If a batch of fresh concrete has already been released on site, collect samples from at least five well-distributed locations. Avoid sampling from the side of the mass, as separation may occur there.

Step-2 (Composite Sample Preparation)

Place all the collected increments as described in step-1 on a non-absorbent plate and mix evenly with the help of a shovel.

After mixing the increments properly, keep this mixed sample in an air tight container, so that it is protected from the effects of the environment/environment.

Step-3 (Sample Information Recording)

The following information about the sample should be recorded before it is sent for testing.

Sample taking date and time
sampling method
mix ratio
Placement of sample batch after placing
temperature and weather conditions