I’ve been hunting through my old posts and searching but cannot find a thread on concrete left over in readymix delivery btrucks and what it is used for… which went on to making concrete blocks… anyone else know the sddress for this thread plaese?
What I’m looking for is all and any concrete blocks knocked out in bulk for assorted construction jobs, parking lot seperation, highway median barriers, snow shields… anything… pics, diagrams,drawings…
TIA
[8D]
Left over concrete in ready mix trucks end up one of three ways.
1- Dumped somewhere nearby during a wash out.
2- Dumped into a catch pond back at the plant to be scooped out later and disposed of.
3- Used somewhere else for a few dollars from someone who does not mind a yard of left overs.
We have a ready-mix truck driver in our HO scale club. If anything is left over it is disposed of at the work site if there is a place it can be dumped and not violate environmental laws;
taken back to the plant and dumped into a settling pond as the truck is washed out;
or taken to a private homeowner who has asked the company ahead of time to bring any leftovers to his or her property if they are close by.
The concrete that settles on the bottom of the pond is periodically broken up and used as filler for roadway asphalt.
The concrete for concrete blocks is a totally different mixture that uses much smaller rock than commercial concrete, and it sets much faster. A concrete block can be taken out of its form immediately after tamping or vibrating, and it will not collapse. Normal concrete sometimes takes hours to cure enough to become that rigid.
In many cases, the ready-mix is a custom mixture according to the project being poured, the temperature on the pouring day, and even the time of day. Concrete for a commercial floor is different than concrete for a sidewalk is different than concrete for a wall, is different than concrete for a roadway gutter, at least here in the desert.
Concrete is rated by Slump. It is beyond the scope of this thread but suffice to say a dallop of rock, a bit of sand and perhaps an additive in different mixes (Trade secrets) produces concrete good for different tasks. I spent a year in a ready mix, lack of air conditioning forced me to greener pastures over the road with air conditioning.
I thought that if there was enough left they dumped it into forms at the plant for those big retaining wall blocks, you know like the 2’ x2’x3’ ones?
Most ready-mix concrete plants do only ready-mix and nothing else. Those concrete barriers would probably be poured by a different company.
No, there are Ready Mix Plants that make concrete fresh for a variety of jobs like Mobile home footings, slabs, foundation footings, sidewalks etc etc etc…
Specialized plants CAN recieve cement and other chemicals and just produce really big culverts, pipes, forms etc that are essentially large concrete items ready to be “Dropped in” at where they are needed.
Concrete Block plants are just smaller versions that make a variety of concrete blocks.
Dont confuse these with Brick Yards and those that make firebrick.
Old concrete can be sent back to be broken up into little rocks and re-used.
I dont consider Home Depot or Lowes type bagged cement “Proper concrete” however. I personally ordered 5 yards of the stuff to lay down a 10’ x 20’ pad for my shed and did the labor myself. Imagine being told that there are tarriff rates kicking in should the truck stay “On the Job” more than 2 hours precisely.
For what it’s worth, that slab has not yet started to crack yet. I can probably thank the little bags of “Fiber” that I threw into the mix… yet another twist to the concrete mystery! LOL.
And lastly there is a type of mixer that can produce concrete in long strips for interstates.
Thats what I’m looking for! [:)]
The thread had pics of several types… most of them could interlock with each other endways and by layers. One had a pair of gloves sticking out of it with “RIP” some famous guy who vanished in mysterious circumstances.
Pics and diagrams of any of this sort of thing would be terrific.
I worked briefly at a place making concrete bridge sections years ago. It’s quite interesting having the office go into shade as a crane swings a fifty foot lump of bridge over the roof. They also used compressed air prodders to vibrate the concrete down into the moulds. When they were working on moulds near the office we had to stop trying to write while the things were rattling away.
'm aware that there are additives for just about everything now from frost to draught via fast setting to slow setting… all with colour choice to be tipped in and stirred.
“When I was a kid…” concrete was grey and just concrete… And my Mum would send me to the shops for six eggs… ow i have to decide what colour eyes I want the chicken to have had… [8)]
AW! [:(][sigh] Come on guys! Help me out here? [%-)] PLEASE? [:-,]
That is about it for me and concrete here. Sorry but I think what I already laid down is starting to cure. =)
Concrete is a mixture of portland cement, sand, and aggregate. The various proportions and type of aggregate determine the ultimate strengths and end usages. The expensive part is of course the portland cement. In cold weather, salt may also be added to resist freezing, and some other chemicals can be used to give “high early” (faster) strength. Concrete companies strive to get the minimum required strength with the minimum amount of Portland cement. The individual bags you buy at Lowes and Home Depot are actually pretty high quality stuff, and if you figure out the cost per cubic yard you will know why.
Cinder blocks got their name from the fact that the agregate originally mostly came from crushed cinders.
Pre-stressed engineered concrete products, such as traffic barriers and bridge girders, are a whole 'nother book on their own.
Dave, Hang on man, I’ll run down to the plant tomorrow and get some photos and measurements. We also have an outfit in town that makes those parking lot sleepers ,you know, the ones they use as parking bumpers,plus septic tanks, front walkup steps and burial vaults.
I’m sorry, but I’ve got to ask…what does a discussion about concrete blocks have to do with model railroading? I assume there’s a connection, it just wasn’t stated what it was anywhere.
One yard of concrete will cover 1 yard by 1 yard of ground to a depth of 4 inches. The prices I remember ranged from 44 dollars for less strength up to about 65 dollars for warehouse floor grade or tornado shelter.
I poured a few out of my truck for locals who bought a certain type of tornado shelter that holds 10 souls and requires about 20 yards (About 10 yards a truckload) total to finish the pour proper but that particular design will also stand up to a nuclear warhead approx 5 miles away and protect against certain radiation for a time.
The problem with ready mix that I remember in the summer was it consumes alot of water. Once a batch is created and dumped into the truck and mixed with plenty of water, you have maybe 2 hours max before it turns your rig into a solid block or unuseable to the jobsite.
You could also do some work in the winter but cold temps affects the pour differently than does hot.
One other twist to the concrete business. Sometimes you can call up a hydralic pump truck to literally “Drink” your concrete load and send it through a pipe up to about 200 feet or so away either up above the second floor on a high rise or over a house to someone’s backyard porch. Those things charge 400 dollars an hour I believe to do the work and are very special rigs in the business.
Stebby, over the years, Bergie has graciously permitted us an occasional non-railroad related topic to chew the bull… it helps alot to talk about industry in general.
I may put up some pictures of a plant that I worked out of which is no longer at that site.
That reminds me… if a cement plant has wheels under the silos, bins and conveyors… there is a very good chance that it is portable and can be packed up and driven somewhere else and set up there. Just need additives, rock, sand and fiber bags along with LOTS of water. Insane amounts of water.
Last time I checked, a “yard” of concrete was a cubic yard: 3’ x 3’ x 3’.
It has the same relationship as barrels, sacks, pallets, drums, crates, trees, grass, roads, parking lots, culverts, bridges, buildings, trucks and a couple of other things… [bow]
OK. I’ll buy that. I will shortly be expecting someone to post a clinic on how to make scale model concrete blocks, in N and Z…[:-^]
Concrete blocks and the attendant pre-mix plant makes a gret lineside industry. This one used to have a service track. Also this plant does indeed use its waste material to cast these retaining wall blocks and the traffic barriers,known hereabouts as Jersey Barriers. The blocks measure 2’x2’x3’ and 2’x2’x6’.You can see the forms for the blocks in the lower picture.
Great Reklein! [8D] That’s the sort of thing I’m looking for! [8D]
Unit Models already does palletised concrete construction blocks in N…
The blocks we had were for company use only to create temporary bins for different stone or other material delivered by dump truck from time to time to make special concrete to order.
Or kept in a certain arrangement to “Encourage” 18 wheelers to stay where they need to be as they work through the plant.