What is Synthetic Fiber Reinforcement and how does it work?

When we first were introduced to the idea of replacing steel with tiny plastic fibers we were like "No way", "doesn't make sense", "will not last"...but its really all about perception and keeping an open mind.

What it takes is some serious research and educating yourself to really understand how this could work.

And what would be the reasons to actually look into this? Benefits?

• Direct cost savings of up to 20% on laid concrete (including site labor)
• Faster construction time (especially in cases of infrastructure roads/toll)
• No corrosion and will far outlast the life time of steel which is prone to rust, concrete cancer and degradation especially where good waterproofing additives are seldom used
• Resistant to fatigue, a common problem when consistently heavy loads are involved
• Reduced (up to zero) plastic shrinkage cracks
• 3-dimensional reinforcement improves concrete point load and impact resistance as well as flexural strength (a test with standard K250 @ Sinar Bali Ready Mix achieved 28 MPA based on a 2kg/m3 loading)

• Lower carbon footprint of up to 60% compared to steel mesh
• Highest cost saving when specifying polished concrete floors
• Time consuming steel transport & placement is eliminated
• Labor costs of steel transport & placement is eliminated
• No concrete cover necessary
• Reduced overall concrete thickness possible
• Increased concrete serviceability life
• Reduced concrete maintenance costs
• Thinner and lighter Precast elements
• Reduced number of rejected Precast elements
• Increased Production speeds
• Increased site safety & efficiency

It all started some 40 years ago when people started to look into the problem of shrinkage cracking in concrete floors and there were a few solutions that were developed to resolve the issue.

There are glass fibers, steel fibers, natural fibers, and a range of micro and macro fibers all used in various applications and with different challenges and benefits.

All of those fibers have some positive impact on shrinkage crack reduction, but only steel and macro fibers have been proven to replace/reduce steel mesh and in some cases steel bar.

But this is not as easy as it sounds either, to specify fibers it requires a static calculation and review of the structural design in order to assess the suitability of fibers and the loading as well.

So before we decided to go into this direction we had to compare various fiber suppliers in order to find out which type of fibers to use and which company to work with.

We started this process in 2012 and a lot of kudos goes to Charlie Hearn from Inspiral Architects who was the first architect willing to work with us on testing this theory and identifying the right type of fibers for the Indonesian construction market.

Initially we used polypropylene macro fibers from a company in the US and we had good results with a few projects using the fibers to replace steel wire mesh in ground floor slabs and also on 2nd floors and roof top when using metal deck (bondek) and even in pools and retaining walls.

We worked on a few projects like Royal Kamuela Resort Sengiggi, Maya Resort Uluwatu, Kokita Villas and Sundari Spa.

We were very reliant on the architect and his projects as he had to ensure that the structural designs were applicable for fiber usage and there wasn't enough support on the engineering side from the supplier.

At first we were offering an all in solution, meaning supplying the concrete mix as well as fibers and super plasticizer as many contractors were reluctant to try by themselves, but we found that this did not offer this solution to a broader market and also did not sit well with the local contractors :)

So in 2020 we found a partner that not only could offer us superior fiber solutions at lowest loading, but also is able to support us with the structural and static calculations to provide confidence to local engineers, builders and developers. The Swiss based @CONTEC Fiber AG

We since have been using CONTEC's Fibrofor Diamond as our standard reinforcement fiber for most applications like ground slabs, slabs on metal deck (bondek), pools and also roads.

The latest projects since using Fibrofor Diamond have been D & D Residence, Makali Villas & Spa, Mr. Sascha Finca Villa (Pererenan) and one of the largest users is Tampah Hills development in Lombok using the fibers for their infrastructure roads and other applications.

We also recently supplied a structural report for a 4,000m2 parking lot at the new Pasar Induk in Tangerang, were we are able to replace double layer of steel wire mesh with only 2kg/m3 of Fibrofor Diamond.

All this was only possible because we are now able to support the engineers and contractors with a static report that shows how the fibers are applied and what loading based on international structural standards and in compliance with global building codes.

We now focus on supplying only the fibers through architects, engineers and contractors, providing education and raising awareness to set a new bar of quality concrete construction in Indonesia.

So now how does it actually work on site?

It couldn't be any easier, the fibers are basically mixed into the ready mix truck or site mixer at a ratio according to the projects specifications in general anywhere from 2-3kg/m3 for Fobrofor Diamond.

All that is required is an added 2-4 minutes mixing time (depending on mixer type and speed) to ensure a good distribution of the fibers throughout the concrete.

Other than that just following the concrete standards set out by the type of concrete for aggregate size and mix design same as for conventional concrete.

If a superplasticizer is used it will make the flow control even easier and allows for a nearly self leveled concrete that only needs to be screed off with an aluminum bar.

The video below gives an insight of some of the possible applications, but they are pretty much limitless and up for your imagination, lately our fibers have even been used for 3D Concrete printing...

If you would like to get a FREE report for your project just send us your structural design files and we will get back to you with 7-10 working days.

Our next goal is to bring our fibers into a Toll Road project, as based on our internal calculations we would be able to offer the operator a huge time saving, enabling them to operate the toll road much faster compared to conventional steel reinforced construction and therefore having a much better ROI (Return on Investment), any leads or contacts in this sector in Indonesia would be much appreciated.

If you are interested to learn more on the topic I'd be happy to share my own research and experience, for personal development, academic studies or simply a passion for more Sustainable Construction methods :)