Concrete2024-07-01T11:41:39+01:00

CONCRETE

Concrete is a mixture of cement (a fine powder usually made of limestone, silicon, iron, and aluminium), aggregates like sand or gravel, and water. When combined it creates the hard and durable material we know as concrete, that is then used worldwide for a range of different purposes. In gardening, it can be used for paving, driveways, or patio, along with other features such as raised plant beds.

The production of concrete has a massive impact on the planet from the intense mining of the raw materials because of high demand, to the production itself which releases extraordinary amounts of co2. Although concrete can be certified it doesn’t stop 8% of all human carbon emissions being related to its production (1). Due to the large negative impacts on the environment from concrete production reducing the amount of hard landscaping in gardens is advised. This could involve adding planting beds and lawns over paving the area and paths made form materials like bark chips to help limit the negative effects. 

Pros:

–Is cost effective, quick and can be done at home with little expertise.   

–Highly durable and versatile, with concrete driveways and patios lasting 30+ years (2).

– Sustainable alternative to cement can be used,  like fly ash which is a by-product of coal fired power plants or using recycled materials like crushed glass or woodchips (3).

–There are certification bodies in place such as the concrete sustainability council (CSC) that aim to promote concrete as a sustainable building material by looking at all stages of production (4).

Cons:

– With sand being one of the main ingredients, the high demand for it can lead to massive environmental impacts.

–Creation of cement produces high carbon emission from the calcination of limestone and the heating of cement kilns to around 1,500°C (5, 6).

– Concrete is water intensive consuming almost 10% of the worlds industrial water supplies and it’s estimated that by 2025 geographical areas that are already under water stress will see most of the water withdrawals for concrete production (5, 6).

–Destruction of habitats, limestone forms particular habitats due to its chemical composition so when quarrying takes place to extract the mineral there would be severe damage to these habitats and associated wildlife (7).

–With 80% of urban spaces being covered by pavements or buildings this leaves little room for green spaces, with many species not being able to adapt to the urban environment. This leads to a reduction of biodiversity and the homogenisation of species (5).

– Overall, cement is responsible for around 8% of world CO2 emissions (1).  

– The transportation of materials from multiple sources to make one product can also increase its carbon footprint dramatically, depending on the location the cement is made in the world. 

– Using concrete creates an impermeable surface, which can affect the soil below as water isn’t able to pass through, potentially causing flooding (8).