What we basically have to do is if it is possible to reuse the material from the street repair instead of throwing it away. They say its is practised in so called "western" countries. What I would like to know what would be the best solution. Doing all the procesess on the street or in a depot nearby. Probably the crushing part will be the biggest challenge as for the noise. Would you suggest we should use a mobile crusher or a dipper-crusher attached to an excavator as well as screen-dipper. Secondly , any suggestions how to do dry separation of the sand from the mud/clay as it is cheaper than wet process. Will be very happy if you share any related experience. Boris
What material are you talking about? Asphalt and concrete are both recycled. Basically they're both ground up and used in new product.
Yes they are but my point is to reuse it on the street repairs , using the same material to fill the hole. You are probably talking about crushing screening and reselling it in general.
On a few of our pavement rehab projects we have the contractor pulverize the roadbed, compact the material then use it as base to pave over.
Yes, crushed concrete is sold as a road material, and it is also used as aggregate in new concrete. Asphalt is ground and sold as a road material, and is used in new asphalt. Still don't know what "material" you're talking about, or is it both?
not a specific one . Example is you do street reparis and the material you digged out if you can use it again on the same place . It can be both asphalt , concrete etc. cause it depends on the particular case.
Like Former wrench said, concrete is sometimes broken and left in place as the base for new paving surface. Or asphalt is milled (ground) and graded and compacted as the base. I've never heard of any system that uses the old material in new material mixed on site. If you are talking about using the broken up material in the fill as you fill the hole, that works as long as you have enough fine material to compact without voids, and you can get away with it. Many times with under street utility repairs, the excavated material is hauled away, and sand is brought back to fill once the repair is complete.
The green-nuts on the west coast have been requiring 'cold in-place recycling' (or some other name like that) where the repaving is a daisy chain of equipment. A milling machine feeds into a pug-mill thing that mixes in cold oil, and feeds it into a laydown machine. Working on the laydown machine or behind the screed is 'cool', the paving is cold AC mix. On the highway that I live on, when it was repaved, large Roadtech machines were used to do 'in-situ recycling'. The grinders or milling machines ground and mixed the pavement with the base, about a foot deep, and mixed oil with it. The machines were connected to oil tankers that trailed them. The result was bumpy as heck, and it was milled flat before the AC base and wear surface were layed on it. There are videos of European hot-in-place-recycling. A *giant* semi trailer sized up-side-down barbecue grill is towed down the road, to melt the asphalt, and a mixing and paving machine follows behind. 10% or 20% new hot mix is added to the old road material, to improve it to some requirement.
Generally the "recycled" part is material brought in from another job. Here in PA, the milling machine will go through and the contractor retains the millings. They are then stockpiled at their yard and used in the next project if possible. Usually the DOT specifies a recycled content percentage that must be met but that is all up to the client. I've never seen a small time operation that removes material onsite and puts it right back.
Here in the uk the new 'in'thing to do is recycle 100% of the material removed. The latest project I have been working on is a pug mill that will blend lime,fly ash and cement with water and waste material to produce a hydraulic bound material that is placed with a paver back down as a base and a thin layer of asphalt on top. All of this is on a trailer which is towed to site.