- Contaminating lakes and other swimming areas with high amounts of zinc and iron, which have proven to cause diabetes, cancer, skin irritation and other adverse side effects
- Exposing fresh waterway to corrosive, caustic concrete washout water and materials that may result in all kinds of damage to ecosystems
- Allowing calcium, magnesium oxide, and calcium – conventional ingredients in ready-mix concrete – to infiltrate our soil systems
Author: Taylor
GBCA Members | Sustainability in the Sydney Building and Construction Industry
- Supporting the creation of buildings and other infrastructure that are environmentally responsible and result in sustainable, efficient, profitable and healthy places for communities to live and work in.
- Fostering a strong bind amongst peers and associates in the building, design, construction, and sustainable operations industries;
- Encouraging the development and promotion of sustainable communities and environmentally responsible building practices;
- Leading market transformation in sustainability and campaigning for the wider recognition of environmentally responsible buildings and practices;
- Supporting and encouraging educational and research programs aimed at raising the knowledge and skill base of green building practitioners;
- Actively aligning with relevant publicly funded research to the practice/market requirements for innovation and development in green building implementation;
- Participating in public debate on environmental issues within the building industry;
- Supporting the campaigning and soliciting of funds to be applied towards the GBCA’s objectives;
- Acting with integrity, due care, and in a manner that upholds the reputation of the works and objectives of the GBCA and Green Star rating tools, its officers and employees.
Introducing PumperDump’s New 5m3 Patent Pending Blowback Bin
With the roaring success of the 2m3 (2 Cubic Meter) blowback bin which launched more than 10 years ago, it was not difficult to notice the gap in the market for something a little bigger. After months of planning and trialling, we are proud to introduce the new 5m3 (5 Cubic Meter) blowback bin to the streets of Sydney.
Our latest innovation would not be possible without the collaboration of some important players in the industry.
We would like to thank Bincorp for the manufacturing of the bin, De Martin & Gasparini for assisting during the construction and for trialling the bin, and WATPAC for permitting this bin to be trialled on their site. We would also like to give thanks to Azzurri Concrete for their input during the construction.
This video shows the second blowback in the same bin without being emptied. PumperDump believes a modest improvement as such could save concrete pumping companies, builders and concrete suppliers money over the duration of a project.
How you ask?
While the delivery line is short and the bin is set in place, you will be able to get a couple of blowbacks into the same bin before it needs to be emptied. Depending on who is paying for the current blowback truck, this could reduce the blowback bill considerably. The bin is also ready at your disposal if there are any problems to occur during the pour – so no waiting for a blowback truck to arrive when time is crucial.
For builders, concreters or concrete suppliers who care about sustainability, there is far less truck movement, reducing the carbon usage associated with a blowout as well completely eliminating the use of plastic, strongly keeping to our policy of no plastic in any of the equipment or waste stream.
Lastly, for the concrete suppliers. There is no need to immediately cart concrete to your yard – reducing fuel consumption, turnaround time for the next load is much quicker, as well as reduced tipping or carting fees for the removal of waste concrete brought back to your yard.
So, depending on who you are in the industry there is a saving for you!
As this is a new system, we have a very limited number of 5m3 (5 Cubic Meter) bins. Nonetheless, we are more than happy to talk to any party interested in using a 5m3 on their current or new projects.
Concrete Washout Guidelines
The disposal of slurry and waste concrete poses a potential risk of environmental harm if not managed appropriately. Creating and maintaining a designated wash-down area allows for contractors to correctly wash down equipment whilst reducing the risk of pollution to waters or land.
Managing concrete washout
Concrete wash water is alkaline (with a pH of around 12) and contains substantially high levels of Chromium, with the potential to harm and pollute land as well as seep into the ground and contaminate groundwater. Concrete washout material, if not managed effectively can increase the pH of surrounding waters in addition to posing potential harm to aquatic life and pollution to waters, including storm water.
Effective concrete washout facilities are used to contain liquids and concrete slurry when the chutes of concrete mixers and hoppers of concrete pumps are washed out after delivery to a site. These washout facilities are utilized to combine solids for simpler reuse or disposal and the prevention of contaminated runoff liquids. Solids that are wrongly disposed of can clog water drain pipes – resulting in flooding. Installing and utilising washout facilities not only assists in the prevention of water pollution but is also considered simply a matter of “good housekeeping” on construction sites.
Location and management of washout areas
The following management measures should be considered to reduce the potential risks of concrete washout areas on the environment:
- The washout area should be situated away from storm water drains, drainage lines and bodies of water.
- The concrete washout area should be conveniently located for washing out equipment and clearly indicated.
- All wash down water is to be contained within the designated watertight bund.
- Concrete washout areas are typically not designed for the gathering of excess concrete. Excess concrete waste should be returned to the local batching plant for treatment and re-use, or placed in a site receptacle designated for concrete and masonry, and allowed to set.
- To reduce the quantity of washout water produced, excess concrete should be scraped off the equipment before it is washed and placed in a site receptacle suitable for masonry and concrete.
- A high pressure, low volume water spray nozzle is recommended to reduces excessive water use.
Monitoring
All concrete washout areas should be maintained and monitored to safeguard that they are fully functioning and have adequate storage capacity.
Monitoring should be undertaken as a minimum:
- Weekly during dry weather
- Prior to forecast rainfall events
- During rainfall events
- As soon as practical following the event of rainfall.
Set concrete should be removed to reinstate capacity to the washout area and prevent overflows.
Environmental Incidents
Lastly, any environmental incidences should be reported. An environmental incident emerges if concrete is washed out in an area other than the designated concrete washout area.
If you are interested in talking to the experts in concrete washout, get in contact with one of out concrete washout solution specialist at info@pumperdump.com.au or by using the PumperDump App (App Store) (Google Play)Ref: Extracted from the NSW Government’s Concrete Washout Guidelines
Dealing with different types of concrete by-product
Advice from the CCAA. New South Wales has over 300 active concrete batching plants that produce numerous concrete by-products and wastes. The NSW legislation and regulations require that all operators remain committed to minimising the amount of new resources used during the production process, to ensure that as much material as possible is recycled or re-used, and any waste which cannot be re-used is disposed of appropriately and ethically.
More often than not, many concrete by-products can be re-used in the concrete batching process without breaching any of the existing environmental regulations. The CCAA has developed a document to provide guidance on the regulatory requirements for managing the four main concrete by-products. These products are specifically known as:
Concrete By-Product | Definition |
1. Hardened Returned Concrete | Hardened Returned Concrete is concrete that has been returned to a concrete plant and has been cured and hardened. Hardened Returned Concrete contains the same properties as normal concrete and is largely free of contaminants, such as wood, cementitious materials, paper, steel reinforcement, plastic and brick. Once hardened, this concrete can be handled and stored with little risk of contaminated water runoff. |
2. Concrete Wash Water | Concrete Wash Water has a high pH (near 12), which makes it highly alkaline, and it also has an excessive matter of suspended solids. Concrete Wash Water is the product produced from washing pumps, trucks, chutes and mixers or simply cleaning out and agitator bowl and hosing down the batch plant yard. |
3. Liquid Wash / Slurry | Liquid Wash Out is an unavoidable by-product of the concrete batching. The washout slurry descends to the bottom of settling ponds and tanks in concrete plants which makes it extremely challenging to pump and transfer. It is also an alkaline material which is exceptionally difficult to re-use in the concrete batching process as it is not a consistent product and it re-use presents numerous concrete performance and technical issues. |
4. Solid Wash Out | Solid Wash Out has the consistency of clay and is returned concrete that has been washed out and dried. It is a mixture of sand and aggregates from the original concrete, and contains hydrated lime and other cementitious materials which sources alkalinity. This material is generally taken out of washout pits, drained, dried, transported to quarries or recycling centres and recuperated for re-use. |
Ref: Extracted from the NSW Government’s Concrete by-product Recycling and Disposal Industry Guidelines
How to Deal with Different Types of Concrete By-Product
1. HARDENED RETURNED CONCRETE
General Exemptions Re-use
Hardened Returned Concrete can be crushed at facilities that have the applicable licences to form recovered aggregates. In this manner it can re-used in the concrete batching process, or applied to the land as engineering fill or as road base.
This material can be applied to road construction on private land if the following conditions are met:
- Development consent for the development has been approved under the appropriate Environmental Planning Instrument.
- The relevant waste is applied to land at the smallest degree necessary for the construction of a road.
- It is to provide access (permanent or temporary) to a development approved by a local government.
The material being applied to the land must be sampled and tested, to ensure that it will pose marginal threat or harm to the environment.
Hardened Returned Concrete cannot be utilised for the following applications:
- Quarry, mine and sand dredge rehabilitation
- Dams
- Back fill for voids
- Utilised in reshaping land for agricultural purposes.
Re-use and Recycle
Concrete Wash Water is generally stored on-site at a concrete batch plant in settling ponds and is recycled into the concrete batching system. This process is advisable as it also reduces the requirement for clean mains water in the concrete batching process.3. LIQUID WASH OUT / SLURRY
Liquid Wash Out is categorized as liquid waste material. As such, this waste is required to be transported by licensed contractors in specialized “sucker trucks”, designed for this task specific task, and disposed of at licenced facilities.
Re-use and Recycle
Liquid Wash Out can be stored in settling ponds, which are stressed to keep the material in a state of suspension. The Liquid Wash Out or Slurry is maintained as such, in its liquid state. The water can then be pumped out and recycled back into the batching process, whilst leaving the majority of the cementitious alkalinity material in the settling pond.
Disposal
If Liquid Wash Out cannot be kept in a state of suspension, the material will collect at the bottom of the settling pond, requiring it to be pumped out and disposed of at a licensed facility.
Transform
The final option for dealing with Liquid Wash Out is to change it from liquid waste into solid waste. This is an advisable process as it;
- increases the number of disposal sites licensed to accept the waste
- increases the ease of handling the waste
- decreases transport costs and disposal fees.
4. SOLID WASH OUT
Disposal
Solid Wash Out does not require a licensed transported and does not entail tracking. Nonetheless, if the material is to be disposed of, it needs to be transported to a licensed facility. At the licensed facility, Solid Wash Out is either re-processed into sand and gravel, it is mixed with various other materials to either fill another product or become road-base.
If you are interested in optimising the way you deal with different types of concrete washout, get in contact with one of our experts for a more efficient and environmentally friendly solution at 1300 366 668 or by using the PumperDump App (App Store) (Google Play)
Ref: Extracted from the NSW Government’s Concrete by-product Recycling and Disposal Industry Guidelines