Expansion cement to anchor bolts in old cinder-block?


  #1  
Old 02-08-10, 03:12 PM
tbird94's Avatar
Member
Thread Starter
Join Date: Jun 2005
Location: US
Posts: 74
Upvotes: 0
Received 0 Upvotes on 0 Posts
Expansion cement to anchor bolts in old cinder-block?

Is expansion cement (e.g. Rockite Anchor Cement) a good product to use to anchor bolts in old cinder-block? I need to anchor bolts in cinder-block that is 45-50 years old. These seem to be made with real cinders, not concrete. When drilling holes, black soot comes out.

The block doesn’t seem to be very dense, and normal anchors work their way loose after a short time. My idea is to drill holes (2-3 inches wide) in the block, and fill with expansion cement to provide a solid base for the anchors.

Any advice? Thanks!
 
  #2  
Old 02-09-10, 03:45 AM
B
Member
Join Date: Jan 2010
Location: North of Boston
Posts: 189
Upvotes: 0
Received 1 Upvote on 1 Post
Originally Posted by tbird94
Is expansion cement (e.g. Rockite Anchor Cement) a good product to use to anchor bolts in old cinder-block? I need to anchor bolts in cinder-block that is 45-50 years old. These seem to be made with real cinders, not concrete. When drilling holes, black soot comes out.

The block doesn’t seem to be very dense, and normal anchors work their way loose after a short time. My idea is to drill holes (2-3 inches wide) in the block, and fill with expansion cement to provide a solid base for the anchors.

Any advice? Thanks!
I've used hydraulic cement to anchor bolts in cement and granite by drilling holes slightly larger than the screw anchor. I've found that it works well if I am careful to be certain that the hydraulic cement bonds to solid material. You need a solid base.

From your description, it doesn't seem that you would have a solid base in the old cinder blocks. Are the blocks hollow and are you proposing filling the entire inside of the block with hydraulic cement?

The hydraulic cement that I've used hardens within a few minutes and I don't know if I could have filled a hollow block quickly enough. Have you tried working with the cement you identified?

Is it possible to use a longer bolt and drill through the block with a washer/nut on the opposite side?
 
  #3  
Old 02-09-10, 01:08 PM
tbird94's Avatar
Member
Thread Starter
Join Date: Jun 2005
Location: US
Posts: 74
Upvotes: 0
Received 0 Upvotes on 0 Posts
Putting a bolt through the block is not an option. And, I'm not planning to fill the entire inside of the block.

I've use expansion cement before with concrete, but not with cinder-block.

Maybe I should ask my question another way: Will expansion cement adhere well to cinder-block?

As I said, these are 45-50 year old cinder-blocks that seem to be made with real cinders (ash). They are not the newer type of blocks made from concrete.
 
  #4  
Old 02-09-10, 02:02 PM
Join Date: Mar 2005
Location: USA
Posts: 5,650
Received 1 Upvote on 1 Post
If you use hydraulic cement, you can lightly spray the opening to be grouted before you force the mixture into the area between the drilled hole and the bolt. Since you have used hydraulic cement before, know the proper mixture and how fast it sets. I can actually be used below water.

Dick
 
 

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