Hardcore compaction issue

[Carrerahill]

Hi all.

 

Quick question, I had 8 tons of 6F2 recycled aggregate dumped on my garage site about 4 months ago, this contained some pretty big stuff - 3/4 bricks and lumps of concrete, fine it was just to get the base fill and once spread over 30m sq it was not that deep so the first layer of type 1 filled all the small voids, this first fill was just about perfect for running a vibrator plate over (less than 150mm rise in fact) and would have been the perfect plan at the time but that didn't work out. I then got another load type 1 delivered and decided to place that round the perimeter of the area to build it up as some will run off into a lower area, at this stage it was still within first compaction limits.

 

I was then on the phone to my merchant who was looking at my account and said he would do me a better rate on the type 1 going forward because I was not being given the full trade price and had bought a lot, so I just jumped at the chance and ordered another load. This load was carefully tipped at one end of the site so my plan was to compact the area that is about level and then shovel all the new stuff out then compact it again, the issue is the area the stuff was dumped on, I am going to need to dig it back down to a suitable depth for first compaction then whack it all, then pull the type 1 back over the area. This just sounds like a lot of extra work, my fault I know but what are peoples thoughts on whacking say a 250mm depth of type 1? By the way, this stuff was compacted to an extent as it went down as I continue to park my Defender on the hardcore and the area that would need dug up has been run over with the Landy about 100 times and feels like concrete now. The loose stuff now sits on top of this.

 

I am going to get the whacker tomorrow morning so could get a fairly big one, I was thinking of the 400mm 12kN or if it would help with my depth issues I could get the  500mm with 15kN but at the same time I have been advised by my structural engineer that using too big a plate could cause issues with surrounding buildings foundations and could also damage my rear retaining wall. 

 

So, what are peoples thoughts here, any similar stories or issues?

 

 

 

 

 

 

[MikeSharp01]

I am sure I read somewhere what a whacker will compact in type 1 depth, much less than 250mm, you probably need a roller for that. Here is a link http://www.broxbourneplant.co.uk/html/wacker_plates.html tells you depends on soil type but 300mm for the bigger one.

Edited October 13, 2017 by MikeSharp01

[Construction Channel]

6 hours ago, Carrerahill said:

shovel

?

have you considered buying a digger??  

[Vijay]

6 hours ago, MikeSharp01 said:

I am sure I read somewhere what a whacker will compact in type 1 depth, much less than 250mm, you probably need a roller for that. Here is a link http://www.broxbourneplant.co.uk/html/wacker_plates.html tells you depends on soil type but 300mm for the bigger one.

 

Info here too http://www.pavingexpert.com/subbase.htm

[Carrerahill]

On 13/10/2017 at 17:11, Construction Channel said:

?

have you considered buying a digger??  

Well I had rented one but it went back after the excavations, in retrospect I should have kept the digger for another couple of days and got my recycled aggregate and Type 1 delivered the following day. 

 

Anyway I did what I described above and now the site is rock solid and fairly level. It took a fair bit of effort to move double handle most of the Type 1 but in the end it was all worth it. 

 

The concrete was meant to be being poured today however I had a shuttering issue at the weekend, it should be built this weekend and the pour completed next week.