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Posted: Fri Dec 19, 2008 10:19 am
by Tony McC
That spec from Giles is almost identical to a spec we regularly used when repairing haul roads in quarries and landfill sites where we had to cope with high volumes of HGVs. I'm fairly certain the concrete would have been C30 or C35.
Posted: Fri Dec 19, 2008 12:07 pm
by oioisonnyboy
did a job earlier this year on the isle of sheppey, new haul road and yard for a landfill site on a farm. We used a pav2 which I think comes out at 35N strength, but it was a blend with PFA to reduce cost as there was so much of it. Only trouble with blended is that it does get a bit sticky.
It has been down for 6 months now and the farmer has probably 100-200 8 wheelers in and out evry day, as well as his fastracs which he uses to tow 21t machines...amazingly that is allowed on the road...even on the M2 at 40mph!!!
Posted: Fri Jan 30, 2009 6:53 pm
by DNgroundworks
Hi again The diagram you posted GB, the expansion joint filling material that is mentioned is only in the top inch or so of the concrete- shouldnt it be full depth?
Just cant work out how that would work, i can understand the movement of the conc and so on but i am a bit confused as to filling compunds.
cheers
Posted: Sat Jan 31, 2009 10:41 am
by Tony McC
That drawing isn't an expansion joint. It's a crack control joint or, it might just get away with calling itself a movement joint.
You're right: with an expansion joint, the compressible filler has to extend to the full depth of the slab. This is then capped with a polysulphide or similar sealant to prevent water getting in and buggering-up the flexcell or the sub-layers.
Fuller explanation of joint types can be found here
Posted: Sun Feb 01, 2009 9:57 pm
by DNgroundworks
Cheers Tony, just another question.
Just to clarify, in what situations would you use a crack control joint, expansion joint, contraction joint, movement joint, construction joint etc
Where would you use one were you wouldnt use another?
Sorry not to experienced in this area, but as they say 'gotta start somewhere'!
Cheers
Posted: Sun Feb 01, 2009 10:05 pm
by DNgroundworks
Hmm just re-read the 'joints for concrete' page - just a bit confused as people are saying to use an expansion joint in the concrete, but as i read the 'construction joint' part, i wondered why in some cases an 'expansion joint' is neccasary and in others a 'construction joint' used??
Cheers
Posted: Mon Feb 02, 2009 5:57 am
by seanandruby
Posted: Mon Feb 02, 2009 11:34 am
by Tony McC
If you consider a stand-alone garage slab that is isolated, that is, it is not directly adjacent to any other rigid structure. As there is potential for movement on all four edges, there's no need for an expansion joint, but, if the dimensions are such that it need crack control joints (let's say it's 6m x 9m) then those joints can be formed as CCJ or simple construction joints. Any expansion of the slab can be accommodated at the outer edges, and the CCJ and/or construction joint will deal with any internal movement.
Bit simplistic, admittedly, but it's a good example of why we have different types of joints.
Posted: Mon Feb 02, 2009 6:08 pm
by DNgroundworks
Cheers Tony:D