Every year we notice that the weather is becoming hotter in summer and colder in winter. We hear in the news that the ozone hole becomes bigger by time, and our beautiful earth is complaining from us. Did you think what you can do to save the Earth? And if you did, did you try to take any action? Well, Engineers did. They have taken steps to solve these problems. Green concrete (GC) is one of the solutions that they started working on in the last 15 years.
GC’s color isn’t green of course, it’s called “green” because it is environment friendly, that’s because its ingredients’ major idea is recycling, which reduces the harmful effect on the environment.
Concrete’s main ingredients are cement, aggregate, and water. Cement is the first problem that has faced civil engineers. For every one ton of produced cement, 0.9 ton of CO2 is produced, and we know how harmful it is. The alternative to cement is using eco-cement, sludge ash, or municipal solid waste fly ash instead of cement, which are less harmful than cement.
The second problem is aggregate. Aggregate is divided into two types: Coarse Aggregate (big size), and Fine Aggregate (small size). One of the main sources to get aggregate is rock mines. That was the main purpose to find alternatives to aggregate. Coarse aggregate can be replaced with recycled aggregates, waste ready mix concrete, or waste glass. Fine aggregate can be replaced with fine recycled aggregate, quarry dust, or fly ash and micro silica. Those replacements are much better to the environment than traditional aggregates.
We know that every new invention is a double-edged weapon. The main advantages of GC are that it’s more economic than traditional concrete TC, since it doesn’t need special preparations, it reduces environmental pollution by reducing the consumption of cement, it has a good resistance to heat and acid, and its compression and split tensile strength are better than TC.
All these advantages can’t make us overlook the disadvantages. Researches and experiments show that the green concrete water absorption is high. Some properties are less than TC like compressive strength, which is not good for concrete, and other properties are higher than TC like shrinkage and creep, which is not good either.
As we know that the need motivates us to think and innovate. We also know that the human brain –especially engineers’- doesn’t give up. I believe that engineers will find the solutions to overcome those problems sooner than we expect. Who knows what the upcoming 15 years hold for us?!