ᐅ Hollow concrete blocks (garage) remain loose after compaction

Created on: 19 Sep 2020 22:31
M
Mojoman
Hello everyone,

Since this is my first post, I’d like to introduce myself briefly.
My name is Stefan, I’m 35 years old from Freiberg, and two years ago I had a solid masonry house built.
I took care of some smaller interior work myself, including laying parquet flooring, painting walls, and attic conversion.
Last year, I built a natural stone wall and constructed a terrace on top of it.
This year, I worked on the exterior landscaping.
I installed 70 meters (230 feet) of curbs around the house, built parking space edging with an adjacent garage, each approximately 6x6 meters (20x20 feet), and today I also paved the parking space.
On the garage’s ring foundation, I laid the first row of hollow concrete blocks to bring the frost protection layer up to the correct level of the parking area so that I can then pave from the parking space into the garage.

Now for my problem.
The paving was done today, but only the parking space for now.
I compacted the entire surface, both parking space and garage, using a small vibrating plate compactor.
While doing so, the four hollow concrete blocks of the garage shifted somewhat.
Thanks to the tongue and groove joints of the adjacent blocks, they stayed in place, but I could still lift them up if I wanted to.

How should I proceed now?

Should I just ignore it since eight more rows will be added? (One block is 33cm (13 inches) long, 25cm (10 inches) wide, and 25cm (10 inches) high, has two hollow chambers, and a flat bottom), … or

Should I remove the blocks, break away the mortar bed from the ring foundation, and reattach them?

Or should I convert the first row into a ring beam by filling it fully with mortar and reinforcing it with rebar?

Thank you very much for your help.
Attached is a photo. The marked blocks are loose.

Best regards,
Stefan

Construction site in the garden with concrete block foundation, wheelbarrow, tools next to parked car
M
Mojoman
20 Sep 2020 15:21
So, I removed the bricks and reset them into the mortar bed. They came out really easily. Strangely, not a single crumb of mortar stuck to the bricks. It all stayed on the ring foundation. I’m glad I redid it.

Regards, Stefan
M
Mojoman
20 Sep 2020 15:36
Hello 11ant,

That also makes me suspicious.
I think that since I did it in midsummer, the coarse-pored bricks had difficulty bonding with the mortar bed.
The moisture probably evaporated too quickly.

Now, before installing, I am wetting the bricks directly, as well as the ring foundation, and then applying the mortar.
I believe this should ensure a good bond to the bricks.
G
guckuck2
20 Sep 2020 18:59
Stone resistant to moisture