×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!
  • Students Click Here

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Determining Particle Size Distribution in cemented, consolidated soils/rocks

Determining Particle Size Distribution in cemented, consolidated soils/rocks

Determining Particle Size Distribution in cemented, consolidated soils/rocks

(OP)
Treatment of cemented or highly consolidated samples with hydrochloric acid results in unusually high silt particle percent (Determination with sieve and sedimentation methods) and sometimes the cemented pieces don't dissolve after treatment.
Is there a more effective method for determining particle size distribution in samples that are stiff/cemented? What is best to use?
The hydrochloric acid that is recommended in the standards is 0.2 M/L

RE: Determining Particle Size Distribution in cemented, consolidated soils/rocks

My first response would be, How do you know the measured silt content is unusually high?
Next would be, what is the mineralogy of the samples? Is more being broken down, in excess of the cementing agent?

RE: Determining Particle Size Distribution in cemented, consolidated soils/rocks

(OP)
We had a couple of samples, where the carbonate content was above 40% and we treated the sample with acid, but we wanted to do a test on the samples with some material that we did not treat with the same process. The clay particle content in percent was way higher in the untreated samples. We noticed a big dip at the 4minute - 8 minute - 15 minute readings in the case of the treated samples, which leads to a lower clay percent (10-15% lower on average)and higher silt percent in the end.

We did not determine the mineralogy of the samples, but almost every sample that we treat with acid has 40-60% silt. We are working with samples that should have predominantly clay particles, according to macroscopic laboratory sample description.

RE: Determining Particle Size Distribution in cemented, consolidated soils/rocks

If your not happy with the hydrometer look for a lab with a laser particle size analyzer.

RE: Determining Particle Size Distribution in cemented, consolidated soils/rocks

Without knowing what the assumed depositional environment of your samples is:
It is very possible the carbonate cementation actually contains a lot of silt.
The clays may be a later product of the chemical weathering of portions of the mineralogy, after the cementation process.
The particles which are cemented may include carbonaceous material, which contains a lot of silt.

RE: Determining Particle Size Distribution in cemented, consolidated soils/rocks

(OP)
It is possible that the cemented parts contained a lot of silt.
How do you prepare your sample for the test if it doesn't break down in acid? Our lab had numerous occasions where even after treatment the cemented parts didn't dissolve.
We're having problem with determining the particle size distribution in highly cemented samples.

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members! Already a Member? Login


Resources

White Paper - PLM and ERP: Their Respective Roles in Modern Manufacturing
Leading manufacturers are aligning their people, processes, and tools from initial product ideation through to field service. They do so by providing access to product and enterprise data in the context of each person’s domain expertise. However, it can be complicated and costly to unite engineering with the factory and supply chain. Download Now

Close Box

Join Eng-Tips® Today!

Join your peers on the Internet's largest technical engineering professional community.
It's easy to join and it's free.

Here's Why Members Love Eng-Tips Forums:

Register now while it's still free!

Already a member? Close this window and log in.

Join Us             Close