Hairline crack in sidewalk slab

Reply

  #1  
Old 09-12-13, 09:17 AM
Member
Thread Starter
Join Date: Jul 2007
Location: USA
Posts: 443
Received 1 Vote on 1 Post
Hairline crack in sidewalk slab

In June, 2010, we had our back steps replaced. As part of the job, two slabs of concrete at the base of the steps were also replaced.
Yesterday, I noticed a hairline crack had formed across the entire width of one of the slabs. My bother in law suggested that I "seal it". My question: should I? and with what?

My current plan is to keep an eye on the crack, and to see if it widens or deepens.
Any suggestions?

(I took a picture, but it is "too large a file" to upload" .
 
Sponsored Links
  #2  
Old 09-12-13, 01:25 PM
BridgeMan45's Avatar
Member
Join Date: Oct 2011
Location: USA
Posts: 3,196
Received 0 Votes on 0 Posts
If it's truly a "hairline" crack, then it's not practical to seal it. A human hair is about 0.003" in diameter; if you place a human hair on the concrete next to the crack, are they both about the same size? In general, most low viscosity epoxies suitable for injection of tight cracks only work if the cracks are wider than 0.005".

The sidewalk probably cracked because of thermal movement, combined with a lack of control/contraction joints--which should have been installed when the concrete was placed, using a grooving tool in the wet mud or sawcutting just after initial set.
 
Reply

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Thread Tools
Search this Thread
Display Modes
 
Ask a Question
Question Title:
Description: