Concrete formwork as we know it today definitely has the look of a modern invention, but its roots go deep. The use of concrete forming products dates back further than you’d imagine. All the way back to ancient Rome in fact.
Concrete Formwork’s Ancient Roots
At its most basic, formwork is simply a mold that supports a liquid building medium while it cures into a solid building medium. With a function that simple, it’s no surprise that our ancient brethren had their own ways of doing the same thing.
There is evidence that ancient Romans used formwork made from reeds in many of their structures. Reeds were especially well suited for use in ancient formwork because they were an abundant resource that was also lightweight and flexible. They were used in both removable and insulating formwork, as indicated by reed impressions and reed remains found in the walls of ancient Roman structures.
From Reeds to Steel
Eventually timber replaced reeds as the preferred material for creating concrete forms. Like the reeds used by the Romans, timber is plentiful. It is also strong enough to withstand the force of the concrete while remaining easy to break away once the concrete has cured.
Timber formwork remained popular until the early 20th century. At which point the Industrial Revolution made hardier materials, like steel, more readily available and increased the demand for larger concrete structures.
Timber formwork is still in use today, though typically for smaller projects. It doesn’t stand up well to repeated usage due to its tendency to swell and warp when it comes in contact with moisture. Steel formwork, which can easily be used multiple times, quickly became the preferred type of formwork as buildings a bridges got bigger and bigger.
Formwork of the Future
Aluminum formwork was introduced in the 1960s as an alternative to steel. Lighter and less expensive than steel formwork, aluminum is an appealing option. Unfortunately it’s also less durable than steel, which reduces its potential for re-use. It’s still available as more affordable possibility, but steel formwork has stood the test of time and remains the preferred material for concrete forming projects today.
From reeds and mud to steel and plywood, concrete formwork has been changing how we shape our world for thousands of years. What will the next innovation in concrete formwork be?