Although its discovery and first use is loosely defined, concrete has been around long enough for its refined variants to make it into the world’s largest, oldest, most ambitious feats of engineering. From sidewalks to skyscrapers, concrete has proven to be among the greatest building material humanity has ever had. Its most common variety, Portland cement, has a more concrete history.
It was in 1824 when Englishman Joseph Aspdin invented Portland cement, which was named after the material’s likeness to the high-quality building stones seen in Portland, England. Aspdin burned finely ground chalk and clay in a kiln to remove the carbon dioxide. This first mixture is far from Portland cement’s modern composition, which is of limestone and clay. It was later when Aspdin refined the material to create the finished cement builders from all over the world are now familiar with.
The reason concrete is so popular extends beyond its durability — countless other materials can offer that quality. No, concrete earned a permanent place on the list of builder must-haves through its ease of use, specifically its simple usage requirement of water. Through the simple act of hydration, builders can ‘activate’ concrete to a highly malleable paste that hardens after some time.
Of course, the volume of materials used will affect the quality of any concrete mixture. Professionals from Form Direct, a provider of concrete construction supplies, note that fresh concrete is at its best when it consists of about 10 to 15 per cent Portland cement, 60 to 75 percent aggregate (gravel, sand or crushed stone) and 15 to 20 per cent water. Mixing the cement also introduces air to the concrete, and they say that this contributes 5 to 8 per cent of the mixture’s final volume.
Proper proportioning of concrete is key when it comes to creating a malleable mix that is strong and durable when hardened. Too much of one material could lead to concrete that is either difficult to place and rough, or easy to place and weak.
The perfect balance between concrete’s simple ingredients is easy to strike with enough knowledge and experience. Builders have limited reasons to use alternative materials in place of concrete, which proves to be everything most construction projects could ever need.