Concrete is one of the most important materials in construction and urban development, and has been for over a century. The eco-credentials of concrete have never been particularly laudable, so the industry is looking at ways to reduce concrete’s carbon footprint.
This extends to the lifespan of machinery and blades. Whilst the equipment manufacturing process is notoriously high in carbon emissions, the durability and quality of the products on the market can lead to less wastage.
By the time concrete reaches the application stage, it has gone through an energy-intensive production process, which emits a huge amount of carbon. The raw materials for cement known as Portland cement, need to be heated up, which produces CO2.
Up to 75% of a concrete mixture can be gravel and sand, known as aggregate. The process of bringing this to market also produces a lot of emissions. The materials have to be excavated using heavy machinery, but an increasingly significant environmental factor is the transportation. The more depleted the local quarries become, the further afield the aggregate has to be transported.
Recycled Concrete Aggregates
The ingredients of the concrete mix could also be developed or replaced in order to make them last longer, whilst reusing waste materials where possible. Recycled concrete aggregates may produce varied durability levels, but it can often work out cheaper as well as more eco-friendly than conventional gravel. As long as its chemical makeup is not tainted by finishing treatments, some readily-available construction surplus could be reused as aggregate for new concrete.
Another area to look at is the lifespan of the equipment used on site. Instead of discarding construction equipment such as saws and grinders, the majority can be repaired or recycled. Waste Electrical and Electronic Equipment (WEEE) regulations were set out in order to address the two million tonnes of devices and machinery that are discarded in the UK every year.
Even if reusing or repairing the battery or mains powered item is not feasible, many of the components can be recycled. Metals can actually be reused within the construction industry, such as zinc for shipbuilding and street furniture; also the copper found in motors can be used for copper pipe and wire.
Construction using cement and concrete will never be known as eco-friendly, but innovations in fabrication, application and legacy can still help to reduce the carbon footprint of concreting.