×
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

Defferennt between 80/100 and 85/100 penetration grade bitumen

Defferennt between 80/100 and 85/100 penetration grade bitumen

Defferennt between 80/100 and 85/100 penetration grade bitumen

(OP)
I'm currently supervising a road to be finished with a double surface dressing.The Contractor is now out of 80/100 penetration grade bitumen.He has requested from the Engineer to order 85/100 penetration grade bitumen as the previous supplier has run out of 80/100 penetration grade.Is there any detrimental effect to the work to allow the Contractor to purchase 85/100 instead of 80/100 penetration grade bitumen?Please assist.

RE: Defferennt between 80/100 and 85/100 penetration grade bitumen

I would be concerned for a couple of reasons:

1.  The 85 penetration sounds like maybe an 80 penetration that didn't meet spec.  Producers usually don't go in 5 penetration increments.

2.  That's a pretty soft asphalt to start.  To soften it even more will cause it to be tacky longer and will require a longer time before it weathers to a stiffer consistency to retain the aggregate.

RE: Defferennt between 80/100 and 85/100 penetration grade bitumen

Correct me, Ron, if I am wrong - but 85-100 is a standard AASHTO penetration grade - they don't have an 80-100 asphalt.  80-100 is typically found in SouthEast Asia - it is what we had in Laos and in India.  The 85 (or 80) to 100 is the range of penetration - you need to check the actual penetration of the asphalt as delivered - it could be 90 which would then meet both specs.  We found that in the hotter climates in India the specs called for 60-70 but really should have gone to 40-50 (which we wanted) but our specs wouldn't allow it - ended up using crumb rubber (not overly happy with it) or polymer modifiers (seemed to hold up much better).  defg didn't indicate geographic location - likely is in Asia (?) but would be buying from US (?) on the 85-100.

RE: Defferennt between 80/100 and 85/100 penetration grade bitumen

BigH...you are correct.  I had not seen the 5 penetration increment, just the range you noted.  I re-read my post and noticed I had the out of spec backwards! Under our spec, it would be the 80 that is out of range.

Not familiar with SE Asia requirements, but as noted, the 85 would be within tolerance if defg is in SE Asia (and actually be within tolerance if in US, though the 80 would not.

I can't imagine he would be using that in a hot climate, though.  Here in the SE USA, that asphalt would flow into the next county.

RE: Defferennt between 80/100 and 85/100 penetration grade bitumen

(OP)
Hi BigH,
Thanks you for the post.The geographic location of the project is Africa(Tanzania).The project road is located in a moderate climatic zone.The bitumen materials(85/100)is expected to be brought from Saudi Arabia or Iran.

RE: Defferennt between 80/100 and 85/100 penetration grade bitumen

Get copies of the Overseas Research Notes ORN-3 and ORN-31. They have charts on the appropriate bitumen to use for chip seals - which would have some validity, I believe, for HMA.  Being in Tanzania, you might actually be using it for chip seals.(?)  The main thing is to get the viscosity correct - you might need to treat with kerosene.

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