THE INTERVIEW HERE:
Journalist: In an era where sustainability is a priority, how has the market for concrete processors grown? What is the fate of the final product?Perry Holt: Curious fact 1: In the last 10 years in all developed countries, not a single permit has been given for completely new quarries and many have closed due to end of life use, thus increasing the price of aggregate on the market today.
Curious fact 2: Too many companies illegally dump and bury their construction waste, with little consequences. This must be stopped in order to get on the road to a circular economy.
Curious fact 3: As of the year 2010, waste creation in all developed countries over a 1 year period, is now at 1 ton of waste per inhabitant. This is considering all waste produced through Construction and Domestic waste. Now you can do the math and see what a big problem this is.
The SOLUTION: By processing/recycling concrete with mobile crushing units waste can be turned into a product again. If material is not recycled you are faced with deposit costs, transport costs etc.
Mobile crushing and screening units are especially capable to recycle and reuse the waste on-site.
Recycled waste can be also sold for a different application such as subbase material for a road.
Crushing and screening means sizing and separating waste material to make a high quality product, which can be reused and therefore has a value, so profit is created.
J: What are the main novelties Rockster brings to the market for Recycling of Demolition Waste? Refer to versatility, capacity and productivity, among others.H: Products need to show flexibility to adapt easily to different applications at low costs. Innovations like the Rockster Duplex system allow customers to use 2 crushing technologies (impact crusher and jaw crusher) on one base machine, therefore 2 different fields of applications can be covered with one investment.
J: What does it mean economically and logistically for clients to have a crusher for concrete processing? How and in what does it benefit them?H: By using mobile crushing machinery customers can turn waste into a valuable product. Therefore they can turn their costs into profit. So instead of buying new aggregate from quarries that are usually far from urban centers, investing in high transport costs and waste natural resources, you can use compact mobile equipment like Rockster's R700S impact crusher to produce aggregate from demolition waste on site and use it eg for subbase.
The Return of Investment (ROI) is usually achieved within a few years.
J: What are the main factors that affect or benefit the demolition and recycling (RCD) tasks?H: Quality of the final grain --> Very important for the future of RCD is the ability to produce CLEAN-CRUSHED-CUBIC aggregate for re-use in the construction industry and at the lowest cost per m3 ton produced. This will increase the appeal to constructors and road builders. Offering recycled aggregate that can compete on price and quality very similar to quarry aggregates, is the future.
Moreover environmental regulations, limitation of landfills, increasing disposal fees, savings on raw material - all resulting in additional costs. With recycling this costs can be turned into profit.
J: Today there are new ways of setting concrete, new technologies that impact on greater hardness or resistance of the material or different impurities, how does Rockster equipment deal with that?H: Higher quality of raw material ends in higher quality of recycled product. Higher quality of end product yields higher price. This covers higher requirements for recycling machinery, especially wear materials as section where a lot of development has already been done.
Moreover, the main factor is the ability to separate metal rebar from concrete, as well as to create cubic material, which is mostly used in construction because it bonds together in a stronger way and lasts very long.
Every Rockster crusher is equipped with a magnetic separator, to separate metal parts (See for example the equipment of the R1000S impactor).
However, with the screening system you can perfectly define the final grain size, so you have no oversize grain and your output is maximized. The impactor produces very clean and cubic final product even with a high crushing ratio.
An additional benefit that Rockster can offer its customers is the Rockster Air Blower, which separates non-aggregates such as plastic, textile, foil, wood, etc. This results in a cleaner and higher quality final product in only one pass.
J: How does it affect when you have to demolish very old structures and the quality of your material is not the same as the current one?H: Older buildings are not a problem for their material content. What is a problem is concrete in older buildings that contain “aluminosis” or “concrete fever” which debilitates the base material and makes it porous. Currently we can mix old building material with newer demolition concrete but a strict analysis must always be done.
In general you can say that reuse of material goes along with the quality of input material.
J: There are more and more infrastructure projects in Latin America, many of them renovating old structures, so what do you expect from the demolition and recycling market for 2019?H: The concept of “De-Construction” has improved greatly in recent years. Also, clients are looking for machinery that are Multi-Functional which can Clean, Crush and Screen all in one go. So Rockster offers a wide range of products, next to crushers we also have different kinds of screens that help to create the perfect grain for re-use in construction.
J: Do you know any projects where recycled construction waste was a fundamental part of the structure?H: Currently material that comes from RCD is only permitted for “non-structural” use in many countries. Structural material however only represents 18-24% of any structure.
The rest of a building such as internal structures, wall flooring, “Visual Finished Materials”, kitchen and sanitary finishing, can all be installed using Recycled construction aggregate, brick, dry wall and other materials.
J: How do they coexist with the norms or legislations that regulate these activities in Latin America?H: The biggest stumbling block is normally the on-site construction manager. He is responsible for the final work and almost always prefers material coming from a traditional quarry. The same applies also in road construction. This person usually does not want to run the risk of “the unknown” of recycled materials, just to be seen as “Ecologic”.
There are many certified laboratories starting up, which “certify” that materials coming from RCD sources are of a certain quality and come with the necessary guarantees.
Many countries are also offering incentives for construction companies to use a certain percentage of recycled materials in new building projects. They usually offer a higher “grade” on the bidding process if a project will use a percentage of “certified” second use material.