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How Precast Concrete Changed Construction, You can read here at GenieBelt’s Blog.

The first time I was aware of pre-cast concrete being used was as a kid in the early 1950’s. In my home town up in the North West, whole housing estates were banged up in no time using pre-cast concrete panels. These were desperately needed to re-house families whose homes had been flattened in the Blitz. Being a ship-building town it actually took bore tons of bombs per capita than did Coventry! My Aunt and Uncle lived in one which it got bombed. He spent 36 hours straddled over a joist. I learnt, many years later after he had passed away, that it didn’t do his love-life any good at all! My grand-parents got lucky.

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concrete_house_in_construction.jpg

By Self Made (Own work) [GFDL or CC BY-SA 3.0], via Wikimedia Commons

The incendiary bomb that came through their roof didn’t go off! Many of these estates sank into becoming “deprived areas” (what used to be called “sink estates”); others are now very nice privately owned areas in the Midlands. Some are very nice but still rented accommodation owned by the LA’s and Housing Associations. Coincidentally I was speaking with a guy last week who was very annoyed! He lived in one of these rented ones – still in good repair; nice estate and he had spent a lot on their home. He was being evicted because someone had decided that these concrete pre-fabs no longer looked good! Visual amenities rule! Okay!

The next major development here was using pre-cast concrete columns for commercial construction, girders and facades to stick up high-rise apartment blocks. I’ve worked on some of those, refurbishing them. The ones I’ve built are in commercial construction are modern ones we stuck up in the last decade or so. This very quickly drifted into the same techniques being used for commercial premises – office blocks. 

 Now this had been done in earlier years, probably from about the 1920’s, but I suspect that the increased usage came about because of the advancing development of cranes; tower and mobile. These made it a lot quicker, easier and safer to lift heavy panels into position. Multi-storey car parks are another big area that uses pre-cast concrete components.

 

precast concrete component

 

 By z22 (Own work) [CC BY-SA 3.0], via Wikimedia Commons

Actually, there isn’t anything particularly “modern” about the use of pre-cast concrete components for construction. The Romans used them for building their Aqueducts and sewers! This is why I suggested that the big change is actually related to cranes. The other thing which has also changed with our modern technology and investment capital, is the manufacturing facilities and transport facilities. We can now make more, bigger, better and can get them from factory to site. The introduction of the use of reinforcing bar and fabric has extended the possible uses of pre-cast concrete components even further.

Another twist to this is that we can probably do our sums better than the Romans could, too. We can now produce pre-stressed, pre-cast concrete components with built-in “bends” in them. For example, if we install a “bent” girder, by the time it has the final vertical loading on it, it is straightened out and sits there all nicely horizontal! The same thing is done in the manufacture of floor slabs.

So what else do we use pre-cast and pre-stressed concrete for? Well, quite a lot, actually; far more than the Romans did! For many of those uses the attraction is the long life and durability of concrete. It withstands extreme weather conditions and is pretty well inert to chemical reactions when in contact with other substances.

It is used extensively in agricultural structures such as silos, feed troughs, slurry channels, etc..

 In buildings it is used, as well as for structural purposes, for site amenities such as fireplace mantels, cladding, trim products, accessories, and curtain walls.

It is also commonly used for the installation of retaining walls, although gabions do seem to be taking over for that job.

Sewers! We use a lot of it for our sewers! The components vary quite widely, too. Linings for manholes; formation of main, large diameter sewers: storm water run-off;   storm water detention vaults to mention just a few.

Then as we drive around we see that the Utility Companies use a lot of pre-cast concrete for their various structures. A lot gets used on the roads we are driving around on, too. Nearly all our kerbs, for example, are pre-cast concrete ones. We go under and over bridges which, again, are often constructed from pre-cast concrete components. The ones I like best aren’t actually on the roads, just alongside them. That is the often beautiful modular paving that we see in the sea-side holiday resorts of sunny Spain!

Another big use, because of concrete’s inert and durable nature, is for the containment of hazardous materials.

 

use of precast concrete constructionWhy to  use precast concrete for construction

By Marleyguy1 (Own work) [CC BY-SA 3.0 or GFDL], via Wikimedia Commons

By Gomera-b (Own work) [CC BY 3.0], via Wikimedia Commons

The last major use I can think of, and for which I’ve used pre-cast concrete components, is for marine products. Here the heavy nature of concrete counters the buoyancy of the water. Floating docks, underwater infrastructure, decking, railings and a host of amenities are among the uses of precast along the waterfront.

So there we go! Pre-cast concrete has certainly changed construction since the Roman invented it! There is a down-side to that, though. Working on site and using a lot of these pre-cast concrete components is about as exciting and interesting as doing a kids jigsaw puzzle!