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Posted: Thu Jul 15, 2010 6:59 pm
by lutonlagerlout
hi all
concrete can be a bitch at times,I went Saturday to do a little job where we concreted a bay last october
i left it with a brushed finish and arris troweled round the edges
it was C30 concrete,it looked very tidy when i left it and there was no frost
anyway,saw it saturday and it looks like someone has shotblasted it
its not cracked or anything and the maintenance manager is fine with it but a lot of the aggregate is exposed
I am puzzled by this
the reason it was done in the first place was that the particular area had maybe 30 artic movements a day (turning) and up wards of 100 2 tonne fork truck movements and the tarmac kept getting destroyed
the maintenance manager revealed that all the forktruck were now electronically limited to setting 1,when previously they were on 5
could forktrucks do this sort of damage??
we did the bay to a structural spec and although there is no grief ,for my own info i wonder what has caused this abrasion?
LLL
Posted: Thu Jul 15, 2010 8:56 pm
by simeonronacrete
Although none of these may apply to your job, here are some possible causes:
incorrect batching of concrete
too wet=laitence on surface which may now have worn away
curing, or lack of
inappropriate trafficking
frost / cold weather attack
chemical attack
washing/cleaning to excess
Whatever the reason if it needs a thin bonded hard wearing screed overlay we have products to achieve this; notably Ronafix Prepacked Wearing Screed
If you want us to pop to site and have a look.....just ask.
Posted: Thu Jul 15, 2010 9:13 pm
by lutonlagerlout
cheers simeon
as i said they are happy with it and its more of an aesthetic thing than anything
i feel the managers remarks about switching the acceleration and speed down on the fork truck must have something to do with it,he said they were losing 1 pallet a week through overzealous driving
now they are restricted they have lost none
the concrete wasn't overly wet,if anything it was a bit on the stiff side,very hard work when 250mm thick
next time i am there i will get a photo
it did rain about 6 hours after it was laid but i assumed that this would be of no consequence,maybe i am wrong
I suppose in reality its not that bad ,maybe just a touch of OCD on my part as no one else is worried about it
LLL
Posted: Thu Jul 15, 2010 9:16 pm
by simeonronacrete
A bit stiff eh - hehe.
Pleased to hear its your high standards rather than their complaint. That's good news.
Posted: Thu Jul 15, 2010 9:19 pm
by Dave_L
Slightly off-topic - We have done a lot of loading yard concrete area repairs lately with tarmac - the advantages of this is the area can be returned to traffic the next morning. Paper mill forklift routes, concrete broken out, reduce level, 300 subbase, 80mm road base and 40mm 50pen 10mm SMA.
The correct material, laid and compacted correctly is very hard and durable, capable of withstanding tri-axle trailers being 'scragged' across it without marking or moving - awesome stuff.
Posted: Sat Jul 17, 2010 12:36 am
by 47p2
Could they have spread salt on it during the frosty weather and it has bitten into the surface?
Posted: Sat Jul 17, 2010 3:13 pm
by seanandruby
Posted: Fri Aug 06, 2010 5:56 pm
by irishpaving
What was temp when you poured it LLL
Posted: Fri Aug 06, 2010 5:59 pm
by lutonlagerlout
middling october morning
foggy IIRC later on overcast
cheers LLL
Posted: Fri Aug 06, 2010 6:09 pm
by irishpaving
Hard to say without photo... Is it just graining on the surface and your been your particular self mate. 
Posted: Fri Aug 06, 2010 10:57 pm
by lutonlagerlout
when i get the photie i will report back
LLL 
Posted: Tue Aug 10, 2010 3:14 pm
by irishpaving
If brush finish mate and you over tampered a little bit under heavy traffic the brush strokes will cut away on the surface
Posted: Tue Sep 14, 2010 9:51 am
by ali79y
Hi
I have been asked by a client for a design specification for a yard with sub-base finish (crushed concrete) with loading of 2.5tonnes/sqm
The ground condition not known yet but I need depth and type of sub base stones? Any advice
thanks
Posted: Tue Sep 14, 2010 12:14 pm
by GB_Groundworks
Hard to say without knowing what the sub strata is like, if your being paid get a structural engineer, he'll need to know what material you are using exactly and what it's made up of. Virgin quarried aggregates have specific loading and strength values, crusher run tends to be a sub standard product in the vast majority of cases, as it normally always contains brick, soil, gypsum etc.
On a previous post I posted a study which showed crusher run with clay brick was alot more prown to erosion from traffic compared to quarried aggregate.