Category: Safety

What’s the Problem with On Site Concrete Washout Trays

Posted on by Richard

The concrete washout tray is the most common concrete washout containment method used on sites. Most trays hold around .8 of a cubic metre.

Sites need to have plant equipment like a crane or manitou to move the tray around empty, and full, and to tip it into the onsite skip once used. Room for storage needs to be found and on some tight sites this could be a challenge.


Trays can be rented or more commonly supplied by the concreter so the builder can look after the waste. All washout trays need to be lined with plastic to prevent the concrete from sticking.

So, over a large project, the amount of plastic used will add up to a considerable volume.

The plastic will contaminate the concrete to be recycled, just like the concrete wrapped in plastic from the washout bags.

For builders looking at a sustainable method of handling the concrete washout waste, this may not be the preferred method.

Washout trays just like concrete washout bags have no alternate method to contain the water overflow when full, and so often spill over the sides to the surrounding area. Like the washout bags, it can create a slip hazard when the slurry dries.

I have had builders tell me that after a couple of trays have been tipped into the skip, the water runs out of the skip onto the road when transported and are concerned about the possibility of fines from the council.

Again, with this onsite tray some builders talk about the extra or “hidden” costs that go with the handling of the trays with their equipment and the cost of the waste when the turnover of the bins is increased because of the weight in the skips.


Some of the problems we have seen:

Storage Issues:

Spills:

Plastic Contamination:

Has anybody seen my washout tray?



Want to know more, then get in touch

Share this article

The Trouble with Concrete Washout Bags

Posted on by Richard

Concrete washout bags are easy to use and are cheap to buy. They are lined with an inner plastic bag to stop the leaching of the washout water. They have tie ropes to keep the bag up while being filled.


Concrete pump operators keep them on their pumps in case of emergencies when builders haven’t thought of organising a washout area. They have a holding capacity of .5 of a cubic metre. When used on site, the builder needs a crane or forklift to lift as the bag would weigh around a tonne or more when full.

We used to sell the bags around 2 years ago but stopped because of the amount of plastic we were taking to the concrete recyclers and our decision not to use plastic in our operation.

Concrete recyclers were also explaining that it was very difficult to remove all the plastic from the concrete, contaminating the

recycled concrete, and the bags outside weaved material getting caught in the crusher causing them to shut down to untangle the material.

The builder’s problems arise when the pump needs more than a volume of .5m3 to wash out and the water ends up all over the surrounding area. This can create slip hazards when the slurry dries or if used on a roadway, as well as time and labour to clean up after the pump has gone. When the bag is picked up full and wet, the slurry often pours out of the bag, as it has no rigidity until the concrete has cured.

These bags are usually dumped into the onsite skip and add to hidden costs as the skip bin will quickly get to its weight limit without even utilising the skips volume capacity. The builders who are adopting a more sustainable future would possibly not use these bags on their sites.

Enjoy the photos.  The next post is on concrete washout trays.

Is this set up really going to work?

Overweight issues:

Need a bigger bag:

Future land fill; there is a better way:

 

Want to know more, then get in touch

Share this article

Challenges and Risks of Working with Concrete

Posted on by Richard

Hello again, as mentioned in our introductory post, over the years we have had feedback from different builders in the industry about their problems.   As a growing company with a specialised service, we have used the feedback to help guide our growth to better serve the construction industry and assist in solving the problems and associated costs in that specific sector and making the full process sustainable. 

Here are some of the things we have learned

  • The cost of waste. The most generally talked about problem, is the increase in cost of waste over the years. Builders on larger sites have the option of getting different skip bins to separate waste streams and increase recycling and reducing the amount of waste going to landfill. The builders on confined spaces, besides having a logistical problem, need to reduce the amount of waste produced on their site. 
  • Some builders tell us that some skip bin companies are having an issue with wet concrete being tipped into their skips. This wet concrete when dried is getting stuck to the inside of the skip and causing a problem when they attempt to tip. Besides getting stuck in the bin, the concrete also binds to the general waste making the separation of waste for recycling difficult, resulting in sending more concrete to land fill.  
  • After a concrete pump has been washed and the washout water hasn’t been contained properly, council fines are a major concern. There is also the labour and time to clean up the mess and the cost can add up.  
  • Hidden costs can make a budget blow out, so more builders are calculating their hidden costs associated with crane or manitou time relating to the movements in delivering and emptying the concrete washout tray, and also the waste cost when tipping the concrete into the onsite skip. There is also the time in finding storage space for the washout tray to live.   
  • Sustainability is slowly becoming more important in the construction industry. Some of you may be nodding in agreement, some may be thinking not the greenies again! Sustainability encompasses, social, environmental, and economic factors. Those ahead of the curve may be looking for new systems to assist them to advance in that area. 
  • Plastic waste is becoming a bigger concern to some in the construction industry as a lot is used when pumping concrete. The contamination of plastic in concrete for recyclers is becoming a bigger problem as recycling of a clean product can make money for some and save money for others. Companies concerned in sustainable practices may be interested in reducing the use of plastic in this area. 

As we go through the different methods used by different builders, I’ll leave it up to you to make your own mind up. Maybe you have done the same or maybe you have found a different method that has helped you make some savings. Feel free to comment as we are here to help each other out. 


Residential Building Waste 
Let’s start with this residential builder. They have decided to contain their washout waste by lining the street with plastic. The common feedback from different builders when shown this shot, is about the hard labour needed to break up and remove the concrete. There is also the time to go to the tip and back, with tips fees, and that time could be better spent out on their boat, fishing! Jokes aside, each of us will have a thought on the cost of time and labour and how each of those can be spent productively.  

  





EPA Fines and Personal Risk 

There is the possible risk of a fine with this waste left on the road, not only as a driver’s hazard, but when the water is released, even though it would be clear, is still very high in pH and would run into the stormwater. 
 
No crane or manitou, just plastic, some shovels, a wheelbarrow and a pile of concrete and couple of young blokes, hopefully no bad backs, and off we go. Not sure what they will be doing with the water? 

Next post, the problem with plastic washout bags.  




Want to know more, then get in touch

Share this article

CONSTRUCTION ALL OVER THE WORLD

Posted on by Richard

Concrete is a major part of construction all over the world, and as time has gone on, innovation in the construction industry has dramatically changed the way we build, while the basis of concrete has not changed dramatically, the way we pour concrete has.

Over the years with this innovation, regulation changes have had to keep up as new construction methodologies adapt. New cost structures to include new safety rules, the use of larger machinery, environmental concerns, and sustainability becoming more prevalent and relevant.

The cost of pouring concrete has also changed as men pushing wheelbarrows were replaced with machines.

Building the Sydney Harbour Bridge

One of the major problems to be addressed in today’s concrete pouring is, where and how to wash that magic machine “the concrete Pump”. Those workers back in the 1930’s only had to wash their hands and a large wheelbarrow, however, todays many costs associated with pouring concrete are varied, with many hidden and un-costed, like fines from water runoff into drains or the hazard of slipping on concrete slurry, overweight skip bins with concrete wrapped in plastic, crane time and labour costs, which all add up. 

Different construction sites and builders use different methods for dealing with these problems, but many builders overlook the hidden costs, which means, they haven’t been addressed or calculated properly as the concrete pouring is still sometimes seen as a procedure still done like it was in the 1930’s and still with the “she’ll be right mate” attitude. 

Over the next short period we will show different methods of cleaning the concrete pump used in today’s construction industry, outlining the problems from feedback given to us by different builders. 

Want to know more, then get in touch

Continue reading “CONSTRUCTION ALL OVER THE WORLD” →

Share this article

Concrete Washout Guidelines

Posted on by Taylor

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 

Share this article

Dealing with different types of concrete by-product

Posted on by Taylor

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
Concrete Pump
 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.
2. CONCRETE WASH WATER 

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.
One procedure applied for transforming the waste from a liquid to a solid, is to pump the slurry into dewatering tubes for geofabric bags.

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 

Share this article