×
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!
*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

Dark lane below the top of sidewalk core

thread592-455393

Dark lane below the top of sidewalk core

Dark lane below the top of sidewalk core

(OP)
I am investigating the scaling of the sidewalk after 2 winters after placing. The dark lane locates about 1 mm below the surface. I am a bit puzzled with a fact that this lane marked the gravel aggregates as well. It's hard to explain the creation of this lane just by improper finishing. Yes, finishing, but again why the lane is going through aggregate particles? Sidewalk was placed 4-5 weeks before snow. A lot of chlorides in. Air is OK. Any thoughts?


https://res.cloudinary.com/engineering-com/image/upload/v1562174175/tips/line_through_aggregate_c-19-424_qaj4ka.bmp


https://res.cloudinary.com/engineering-com/image/upload/v1562174066/tips/wide_view_of_line_c-19-424_nf3o9g.bmp


https://res.cloudinary.com/engineering-com/image/upload/v1562174091/tips/line_through_sand_and_paste_c-19-424_zucqb9.bmp
Replies continue below

Recommended for you

RE: Dark lane below the top of sidewalk core

This is clearly a finishing issue. The dark zone that drifts upward into the coarse aggregate was caused by bleed water trying to reach the surface but the surface was dried and finished before that could happen. The distinct line just below the surface results from overworking the drying surface with a weakened cement paste....that is why it separates from the coarse aggregate.

The darkening below the coarse aggregate is also an indication of retempering, that doesn't mix well in the paste.

A Great Place For Engineers to Help Engineers

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


News
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