×
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

Jobs

Concrete joint technology
2

Concrete joint technology

Concrete joint technology

(OP)
I have been out of the highway/flatwork pavement industry for a few years. I am trying to help a long time client evaluate concrete versus asphalt pavement for a several large projects coming up. They are in the trucking business with terminals.
We are getting pros and cons from both industries.

The concrete guys say they have joint deterioration problems resolved wiith special inserts, saw cutting joints, etc. and can eliminate steel reinforcement with higher strength concrete mixes.

The asphalt guys save they can resolve swaling and rutting with several new methods.

Anyone with real life experience or good studies.

RE: Concrete joint technology

2
I would use a combination of the two. In the high abrasion, high concentration areas such as the truck docks and trailer staging areas, I would use concrete. Specify that sawcut joints be made the same day as placement and no more than 8 hours after finishing. Joints should be no more than 12 to 15 feet in any direction and should be cut to a depth of 1/4 of the section thickness. Make sure that the concrete thickness tolerance, both over and under is met. Use dowels in all transverse joints. I usually do not specify reinforcement for the concrete, though wire fabric, if placed properly is desirable. If no wire fabric is used, then use steel fiber enhancement to the concrete. Polypropylene fibers are worthless for this application.

The higher strength of concrete is somewhat irrelevant. Use 4000-5000 psi concrete and don't worry about it.

As for the transition between asphalt and concrete, place the concrete first and slope the face of the concrete toward the asphalt by about 15 to 20 degrees off vertical. This will help keep the interface joint sealed, because when traffic goes across the joint, it pushes the asphalt against the concrete, keeping the seal intact.

RE: Concrete joint technology

@Ron

In thirty years, I've never seen your concrete/asphalt joint solution before in plan or practice, but it's so obviously a good idea I don't know why it isn't always done. I'm going to put that one in my personal bag of tricks. Thanks!

RE: Concrete joint technology

Thanks, Hoa. After reading my post, I described it incorrectly, but I think you got what I meant. I should have said that I slope the concrete AWAY from the asphalt, not toward it. Just designed one today for stamped concrete golf cart paths across an asphalt roadway. I've been using this detail for about 20 years and it seems to work.

RE: Concrete joint technology

Ron - I like the idea because it should keep the joint sealed as you mentioned. Also, a common problem with these joints is the same problem as when there is a joint between two concrete slabs with nothing to provide load transfer between the two joints. Your design provides a degree of load transfer and support right at the location the asphalt pavement is most vulnerable.

How did you arrive at the 15 - 20 degrees? Have you experimented with a steeper angle?

RE: Concrete joint technology

Hoa...if the angle gets any steeper, the concrete will tend to break off. Keeping it only 15 to 20 degrees off vertical prevents this....sort of just enough to cause the push against the concrete, but not enough to create a ledge on the concrete.

RE: Concrete joint technology

(OP)
Thanks for the help Ron. I meet with the client next few days and will give them the info with my other research
Thaks again

RE: Concrete joint technology

Ron .. good Idea from your side for this concept of joint. I think it will be useful for paths with light load but I think if we use it in high load, there are many problems will appear like creep and so it will make cracks .. thank you

RE: Concrete joint technology

(OP)
Thanks Ron, Hoa & Almo. This is what i needed. Tuning off thread

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!


Resources