[Explored] Can Recycled Concrete Be Used?

After demolishing a structure each year, a huge amount of construction and demolition waste generates. Now you may ask whether this waste goes and if there is any chance of reusing them by recycling.

Well, the answer is yes, recycled concrete can be used in construction work. According to a report by CSI (Cement Sustainability Initiative) on using recycled concrete, they argue that the recycling of concrete can reduce natural resource exploitation and waste going to landfill. The report asks for an ultimate goal of “zero landfill” of concrete. And worldwide, demolished concrete is recycled and used in construction work.

In today’s article, we have shared the facts about whether you can use recycled cement or not, where you can use them, and the advantages that can be achieved by using recycled concrete. So, without any further ado, let’s begin!

Is It Good to Use Recycled Concrete in Construction?   

Every year, about million tonnes of concrete waste are generated, according to the CSI, in Europe, the amount is 510 million tonnes, and in the USA, the number is 317 million tonnes. 

While in some countries near full recovery of concrete is achieved, in most parts of the world the potential to recover concrete is overlooked and it ends up as unnecessary waste in landfill. This is generally the result of low public concern, as the waste poses relatively low hazard risks compared to other materials.

The recovery of concrete falls between standard definitions of reuse and recycling: concrete is broken down into aggregates (granular material). 

However, using recycled concrete can achieve nearly the same compressive strength as fresh or virgin concrete. According to research by Dhiyaa Mohammed et. Al., virgin concrete can achieve a compressive strength of 30.9 MPa whereas if you replace the virgin concrete with 50% of recycled concrete with 10% Silicafume admixture then the concrete can gain a compressive strength of 30.8 MPa. Also, if you want to use fully recycled concrete with 10% Silicafume admixture, then it will be able to achieve 29.2 MPa.

So, here you can see that, the compressive strength difference between recycled concrete and virgin or fresh concrete isn’t that much. Hence it can be said that it will be an ideal decision of using recycled concrete. 

CSI has made research and created a full report on the use of recycled concrete. Here we have attached the PDF, if you want to gather detailed knowledge, then you can use it as a reference.

Where Recycled Concrete Can Be Used?

Recycled concrete is widely used around the world and it can be used as the base for roads, driveways, backfill material, shoulder stone, and so on. CSI has made research and, in their report, they have provided the usage of recycled concrete in different countries.

• In the USA, 38 states use recycled concrete as a sub-base material and rest 11 states use it as new concrete.
• In the Netherlands, concrete is fully recycled and used for different purposes rather than landfilling.
• In Brazil, they are using recycling facilities for recycling concrete waste to use as a road sub-base material.

Like these countries, South Africa, Qatar, UAE, Kosovo, Belgium, Thailand, Japan, China, Australia, and other countries are recycling concrete and using them in the aforementioned sectors.

Advantages of Using Recycled Concrete

There are several advantages of using recycled concrete. Here we have provided the key advantages.

• Transportation can be reduced as the concrete can be recycled on-site. Saving of money, as well as less fuel, will be emitted. 
• Won’t need to use the concrete waste as landfill material. You will able to save $0.25/ton/mile and by this less land will be disturbed as virgin alternatives can be conserved.
• Have good compaction and density properties.
• Recycling one tonne of concrete can able to save up to 6,182 liters of water and 900kg of CO2.

Frequently Asked Questions and Answers – FAQs

How much demolished concrete can be recycled?

Concrete can be recycled fully or can be recycled partially. In the Japan and Netherlands, they have recycled concrete waste fully and are successfully using them. In the USA, the percentage is around 82% or higher. It will depend on the technology, the higher the technology is, the higher percent of concrete waste can be recycled.

Can recycling concrete reduce the carbon footprint?

Sadly, the answer is no. Basically, the emission of carbon footprint depends on cement and concrete has a very lower carbon footprint compared to cement. Most greenhouse gas emissions occur during cement production.

Conclusion

Lastly, using recycled concrete can be beneficial for you in different purposes but you will need to be conscious while using them. Because it is not suggested to use recycled concrete in every type of structure but you may able to use them in the future as none of us haven’t seen the future. There are myths like concrete can’t be recycled or can’t be used but we hope, by now, you have answers against the myth and you know what to do from now on! Happy constructing!