Any tips on how to loosen this concrete?

twopenny

This gorgeous and desirable 😕 part of my access had these 3 block pavers missing when I moved in 7yrs ago.
I've tried various concretes that were in my shed but they just fall off again eventually no matter how much preparation I do.

Now I've bought some adhesive but can't chip off the old concrete to get it level which is important with a step.
Tried bolster chisel, wood chisel, hammer, probably other things and can't get even a small bit to budge.

What technique am I missing please?

Section62

twopenny said:

This gorgeous and desirable 😕 part of my access had these 3 block pavers missing when I moved in 7yrs ago.
I've tried various concretes that were in my shed but they just fall off again eventually no matter how much preparation I do.

Now I've bought some adhesive but can't chip off the old concrete to get it level which is important with a step.
Tried bolster chisel, wood chisel, hammer, probably other things and can't get even a small bit to budge.

What technique am I missing please?

A bolster with the blade flat across the top surface of the brick should be working.  You want the cutting edge to get between the mortar and the brick.

You'll be left with annoying bits of mortar which will need chipping off, and be careful not to disturb the pavers behind the row you want to remove.  Also make sure you are using eye protection.

You'll also need to use some motar, not just adhesive.

twopenny

Thanks Section, I've tried the bolster with no effect on any of it.
Goodness knows what I used that's so tough!
But obviously I'll give it another go.

Yes, always eye protection as I wear contacts.
And learned the lesson when I was younger and working on a car 😕

As for loosening others I would like the whole lot out but even a seasoned builder said don't touch it. It was designed for wheelchair access and probably a selling point round here.

Section62

twopenny said:

Thanks Section, I've tried the bolster with no effect on any of it.

Try starting in the red circled area - it looks like there's a bit of a gap you could get the edge of the bolster in to start you off.

The colour of the mortar suggests it was a pretty strong mix... maybe with some PVA added as well.

WIAWSNB

Are you saying you actually have the three missing paving slips? If so, how well do they fit - nicely level with their neighbours? And the surfaces 'mate' neatly - ie, you need to put the correct slip in each space? So all you need is an adhesive? No gap-filling to do?

If so, wire brush all the mating surfaces, vacuum debris, and spread on just a smear of Stixall to both surfaces. Place pave slip in position, wood block on top, tap repeatedly to bed down firmly. 

Almost certainly jobbie whatsitted. 

twopenny

The gap circled is the only bit I got off.

The pavers I have sit proud by a tad. That tad could be a tripping hazard so I really need them flush.
I'd previously chipped away all the old concrete and did a proper job. 
They came out again so I lathered on what I had in the garage, no PVA added, goodness knows what it was.

It's on of those jobs you think won't take a mo and it's gone on for ages trying the expected way.
I'll go and get changed and get the bolster out again 

WIAWSNB

What other tools do you have? An angle-grinder?! 

If so, I'd be tempted to run a groove in the concrete bed alongside the remaining slabs, so that your chiselling doesn't lift off beyond this.

You could even run some grooves an inch in from that edge, and shove the bolster in there - good chance it'll help if you are removing such narrow strips. 

FreeBear

Section62 said: A bolster with the blade flat across the top surface of the brick should be working.  You want the cutting edge to get between the mortar and the brick.

You'll be left with annoying bits of mortar which will need chipping off, and be careful not to disturb the pavers behind the row you want to remove.  Also make sure you are using eye protection.

And is is also advisable to put some boards up against porch/conservatory to protect the glass. The sealed units are likely toughened glass, and it will only take one small bit of shrapnel to shatter an entire panel.

An angle grinder with a diamond cutting disc would help to cut the old mortar up so that a chisel can break it off. But yo may find whacking at it with a big hammer could cause the lower mortar joints to fail and/or crack some of the bricks.

twopenny

I would love to be able to cut a grove WSNB!

I'm aged with arthritis so buying an angle grinder is out. 
Neighbours aged and unwell.

Section62

twopenny said:

I would love to be able to cut a grove WSNB!

I'm aged with arthritis so buying an angle grinder is out. 
Neighbours aged and unwell.

So we can cross 'pneumatic drill' off the list as well then? 

twopenny

It did cross my mind Section.
I'd like to take one to the whole lot!

However, weirdly I've managed to take enough of the cement off with a small hammer.
Turns out the cement has softened with our 3mts of heat. Even to the point of damp under a very thin crust.
I have no idea how that works 🤔

I've got enough off to visibly level 🙂

So for anyone else trying to deal with concrete severe heat seems to work. Not what you'd think.