Construction pollution has many forms from air, water, soil, and/or noise pollution. This is caused by materials used, such as harmful chemicals used during the construction or waste being dumped in sensitive areas or construction sites that are close to fresh water sources.

The most common types of pollution found on Construction sites are dust and diesel emissions. Dust pollution being a very common Construction Site pollution, It may contain Microscopic solids or liquid droplets, they are minute enough to seep into the lungs and cause health issues such as wheezing, Bronchial infections, dermatitis, Asthma attacks and more. It can also contain chemical particles that can cause long-term Health issues.

Out of 195 Counties, South Africa currently sits at 37 on the list of the most polluted, with stats standing at 21.56 Average PM2,5 (Fine particulate matter 2.5) refers to tiny particles or droplets in the air that are two and one-half microns or less in width.

The source of this pollution is car, truck, bus and off-road vehicle exhaust fumes and from building and other operations that involve the burning of fossil fuels such as wood, heating oil or coal. Consideration to our communities around our construction sites plays a role in reducing pollution on site and the surrounding areas.

Ways to reduce Construction Pollution

  • Time: Consider time management on site. Decrease the amount of time spent on site. Modular construction can decrease time and speed up the process. “Modular construction – is a process where pieces and structures are built off-site in manufacturing plants before being transported to the job site
  • Vehicles: Construction sites require the use of machinery. It is a tough one to overcome. However, the use of economic fuel-efficient vehicles “Tier 4 equipment” reduces hydrocarbon emissions. Reducing machine idling time can also help reduce emission and will benefit in more ways than one by also reducing fuel expenses and reducing air pollution.
  • Clean-Up: No one enjoys cleaning up after a long day’s work. So create a clean-up policy, have bins laid out across your construction site, so your workers can have a clean Working environment and ensure waste is removed safely and not affecting surrounding environments

Turning Trash into Treasure

Landfill health needs to be addressed urgently in South Africa.

A recent research study regarding landfills in South Africa found that: During the period of 2008 to 2015 there was a significant increase in the number of waste sites – from 42 to 1,086 in 2015. The analysis also indicated that the distance from residential homes to the nearest site decreased from 68.3km in 2008 to 8.5km in 2015

The analysis further showed that people living within 5km of a waste site were at a higher risk of certain health conditions. Higher health risks determined were: a 41% higher risk of asthma, an 18% higher risk of developing tuberculosis, a 25% higher chance of having diabetes, and an 8% greater chance of having depression compared to those who lived further than 5km from a waste site.

There has been an increasing amount of waste & building rubble produced by an ever increasing population and its associated activities and the expansion of metro areas throughout SA.

The result is that enormous volumes of waste & rubble are being produced in high density, rapidly expanding living areas with insufficient waste management systems and waste processing plants and areas to effectively deal with the growing volume.

This also leads to vast unsightly and dangerous areas in Urban cities, where building rubble is dumped illegally, creating further health and safety concerns.

In developing economies such as South Africa, costly and complex waste operations must compete for funding with other priorities such as clean water and other utilities, education, and health care. Waste management is often administered by local authorities with limited resources and limited capacity for planning, contract management, and operational monitoring. These factors make sustainable waste management a complicated proposition and most low- and middle-income countries and their cities struggle to address the challenges. The impacts of poor waste management are dire and fall dis proportionally on the poor, who are often unserved or have little influence on the waste being disposed of formally or informally near their homes.

According to a 2018 report by the South African Department of Environment, Forestry and Fisheries, only 10% of our waste is recycled. The remaining estimated 98 million tons is deposited into landfill sites each year.

Comparatively South Africa produces less waste per capita (around 0,5-1kg per person per day) compared to many other developed countries where up to 1,5kg of waste or more is generated per person per day. The difference is that these developed economies have far more advanced waste management systems in place that ensure that up to 70% or more of their waste volumes are recycled.

Concrete Facts – The Sustainability of Concrete in a modern Urban world
By David Dworcan, CEO Aggreg8

As the world continues to urbanize, many countries will face challenges in meeting the needs of their growing urban populations, including those for housing, transportation, energy systems and other infrastructure, as well as for employment and basic services such as education and health care.

The United Nations projections for Urban settlement indicates that over 68% of the global population will be Urban dwellers by 2050 – only 29 years away.

The Global trend towards urbanization will result in many countries facing massive challenges in meeting the dwelling infrastructure needed to provide adequate community infrastructure in growing urban populations, including housing, transportation, energy systems, as well as infrastructure for employment, education and health care services.

It is estimated that as much as three in five cities worldwide with at least half a million inhabitants are at high risk of a natural disaster. Collectively, these cities are home to 1.4 billion people or around one third of the world’s urban population. Developments of the future need to have greater weight placed on environmental impacts.

Wide use of concrete structures in urban developments can not only reduce environmental impact but also ensure longevity of structures with the added benefit that concrete is fully recyclable.

Concrete Definitions

  • Concrete is a versatile building material, in fact Concrete is the most man-made used substance. Concrete is made of cement, sand, aggregates, water and admixtures. It can be molded when in it’s in a “wet” state and solidifies over time, gaining strength and durability.
  • Cement is the ‘glue’ which binds the ingredients of concrete together. It is a powdery material which when mixed with water, sand and gravel forms concrete. When mixed with water and sand it makes mortar.

The amazing properties of concrete:

  • Non-combustible – Concrete does not burn: providing fire safe structures especially in Urban settings
  • Non Oxidative – Concrete does not rust: providing low maintenance and durability
  • Rot-proof – Concrete does not rot: reducing risk of unseen damage
  • Insect-proof – Concrete does not suffer from insect damage: reducing risk of unseen damage and longevity of structures
  • Flood-resilient – Concrete does not swell and warp when wet: providing resilience to flooding and internal water damage
  • Zero emissions – Concrete does not emit volatile organic compounds (VOCs) that can harm the environment
  • Water non toxicity – Concrete is inert: it can be used to store and supply clean drinking water safely
  • Heat-reflective – Concrete has high light reflection: the light-coloured surface of concrete reflects heat whereas dark surfaces like asphalt absorb heat and cause the problematic urban heat island effect
  • Water-permeable – Concrete paving can be created to be permeable to water: This reduces flooding during heavy downpours as water can permeate through the surface
  • Reduces vehicle emissions – Concrete paving is very rigid and forms hard surfaces that are vehicle friendly and provide great traction thereby reducing vehicle emissions
  • Thermal mass – Concrete has thermal mass, like stone and masonry, which can be used by designers to reduce energy demand.
  • Range of Densities Possible – Concrete can be made in a range of densities from lighter than water (10kN/m3) to heavy concretes (30kN/m3) that are used in hospitals to absorb radiation: typical concrete density is 23kN/m3
  • Compressive strength – Concrete has compressive strength: strengths from 5MPa (economic low strength masonry) to 80MPa (high rise buildings) and can be designed to have more than double this strength for ultra-high performance
  • Tensile strength – Reinforced Concrete has tensile strength: concrete is compatible with reinforcement steel which provides tensile capacity and together they make the most widely used composite material in the world
  • Available & Affordable – Concrete is locally produced. It is widely available and suitable to build at a reasonable cost, without compromising on quality and strength and with low maintenance costs
  • Recyclable – Concrete is one hundred percent recyclable. All its components are recyclable which can support a circular economy with environmental benefits, job creation and renewable resources.

Concrete Sustainable benefits

Taking a whole-life cycle performance into account, concrete has a low carbon footprint thanks to its durability, to its thermal mass effect, to its recyclability and to the carbonation of cementitious materials. South Africa has a great opportunity to build sustainable and environmentally friendly urban developments through promoting the use of concrete and better management of building waste by building material recycling regulations into its policies.