Unhappy with block paving

[Pacaho]

Hi All,

I'm new to the forum and basically I'm after a bit of advice.

Seven weeks ago I had my drive & patio area block paved. The end result was perfect, however over the last week or so the entire area has changed beyond belief. Holes have started appearing all over the surface of the blocks. Upon close inspection embedded into the surface of the blocks is what can only be described as 'Coal/coke/charcoal??'

The 'Coal/coke/charcoal??' is then crumbling away leaving holes, some of the holes are up to 2cm in diameter. Not only this but there are also a number of the blocks that are crumbling on the corners.

I immediately got on the phone to the firm that had supplied & laid the blocks. The firm in question is a well established one who have a very good reputation in my local area. They came to see the blocks within 24 hours of my phone call. Upon arrival they agreed that there was a definate problem with the blocks & they got in touch with the manufacturer.

What is happening now is a rep from the company who manufactured the blocks is coming to see me in the next few days to inspect them.

As far as I am concerned the blocks are sub standard & should not have deteriorated to such a degree over such a short period of time. I must therefore be well within my rights to have the faulty blocks replaced.

Has anyone else out there ever heard of blocks having pieces of 'Coal/coke/charcoal??' & then holes appearing everywhere?

Any help or advice appreciated on this.

Cheers.

Paul

[lutonlagerlout]

never seen this before, but they shouldnt be falling to bits at this stage ,stick to your guns mate and go for a full re-installation if the blocks are at fault
cheers tony

[Pacaho]

Thanks for that quick reply Tony.

Anyone else come across 'Coal/coke/charcoal??' on the surface of blocks?

Just to give a clearer picture of this problem, the blocks that have this on the surface, (About 80% of them!!) the size can be anything from 3mm-2cm in diameter. You can actually pick some of it out with your finger nail. Other bits are a little more stubborn but will come out with a little help from a penknife. When it does come out it just crumbles up into a black powdery substance. The end result being an unsightly hole in the block.

[Dave_L]

Can you post up a pic of said areas?

[Pacaho]

To the left (Circled.) is an example of the 'Coal/coke/charcoal??' that can be seen in the surface of around 80% of the blocks.

To the right is what happened after one piece of 'Coal/coke/charcoal??' crumbled away. As you can see it has left quite a bad hole.

This is not the only hole that has appeared, I have lost count of how many holes I now have in my driveway & patio area.

It's not just the holes though, blocks have cracked, many have crumbled. My driveway & patio area looks like its been down 7 years not 7 weeks.

Another thing that I forgot to mention in my original post......taking into account that these are red blocks, is it normal to have what looks like bits of white marble, white plastic & what even looks like light coloured wood embedded in them?

I think I've copped for the worst batch of rejects in living history.

The rep will be here tomorrow around 10.30, lets see him try to talk his way out of this one then.

[Pacaho]

I've just had the rep round. In his opinion the blocks are not right. He has taken photos & he will now have to submit a report. He has now gone on to see the firm that layed the blocks.

However there has to be a further inspection of the blocks.......by a technician!!!!!!! They will do the same....look at the block pavers...............by all accounts it is up to the technician whether we get the entire lot replaced or not. This technician should be visiting within the next couple of weeks.

The rep seemed pretty confident that we will get the lot redone..........we'll see.

If we don't get them replaced I think the next step is trading standards???

As things progress I'll update this thread.

Thanks for help/replies.

Paul

[lutonlagerlout]

looking at them i would say its a defo,looks like someone is in for the high jump at the manafacturing plant,
cheers tony

[Dave_L]

Looks terrible!

I'm sure it will all fall in your favour.

Do let us know how you progress!

[Ross-Paving]

I have seen worse that this, sub-standard blocks was the accepted outcome and supplier replaced all plus paid for labour. Don't rest until it meets your expectations.

[simeonronacrete]

It's probably something called "lignite"; read the following...an American article found via Google using "lignite concrete" as my search string....

Q. I had a concrete driveway poured 7 days ago, and noticed a couple days ago small pop marks throughout the concrete. The concrete finisher spoke with the ready-mix producer, and the salesperson said it could be lignite. Do you have any suggestions on what should be done with my concrete? Will it continue to pop? Is there some type of sealer that needs to be put on it? Should I have it torn out and redone? I live in Kansas City, Mo., and the concrete was poured early on a summer morning, before the temperature hit 100[degrees]. For the next couple of days a water sprinkler was on it to keep the concrete cool.

A. The small pop outs that are occurring on your new concrete driveway are sure to be an irritation. Nobody wants or expects that kind of thing when they have a new driveway installed. From what you describe, and if there was indeed lignite in the concrete, it sounds like the problem stems from the fine aggregate (sand) used to make the concrete.

Lignite is sometimes found in natural sand. The amount varies, depending on the quarry and the particular deposit. When sand containing lignite is used in making concrete, lignite particles near the surface can expand and cause the pop outs you describe. Although it sounds as if the placement and curing methods were appropriate, working the concrete can move the lignite toward the top. At first you'll be able to see the small, dark lignite remaining at the bottom of the pop outs. But because it is relatively soft, it will soon wash away.

There is a standard limiting the amount of acceptable lignite in fine aggregate, ASTM C33, "Standard Specification for Concrete Aggregates." It addresses both strength concerns and the concrete's fitness for the purpose, which includes appearance issues. Although the standard allows up to 1/2 percent "coal and lignite" (for pavements), it permits a higher percentage if the strength is not adversely affected and some other non-expansive criteria are met.

How you deal with this problem depends on how unsightly you find the finished product. If you have one pop out per square foot, it might not be worth pressing the issue. But if you're averaging a dozen pop outs per square foot, it might be worth the aggravation you're sure to encounter if you try to have the contractor or producer remove and replace the concrete. If you pursue that, you might want to find a consulting engineer who specializes in concrete and will probably end up taking core samples for analysis.

The strength of the slab should not be adversely affected by the lignite content. Applying a sealer may help keep additional water from getting in and expanding any more of the lignite. If you choose to try that, choose an acrylic sealer that has good moisture vapor transmission qualities.

COPYRIGHT 2004 Hanley-Wood, Inc.
COPYRIGHT 2004 Gale Group

[Tiatodd]

Had this problem once b4 myself.Always use Plasmor blockpaviours and they had a problem with the aggregates they were using. Plasmor agreed to supply new paviours and paid me to take up and relay the entire driveway.The customer was entirely satisfied.Hope you get the same result.As a contractor couldnt praise Plasmor enough for upholding our reputation.Hold out for the same or compensation

[TheVictorianCobbleCo]

I could quite easily be wrong here but I am of the opinion that the manufacturer has included burnt coal/ash scale into his mix. I can't remember the exact name for it but it would explain what's happening. I've also heard of some paving manufacturers bulking their mix with it. The technician is a play for time, whilst he can do no harm, I think you have enough on your side to demand full replacement, and protect yourself by having them show you beforehand what they are going to put down - they should even be able to supply a spec sheet for the replacement product. Good luck.