How to make the strongest possible concrete repairs using epoxy injection technology

While attending the World of Concrete trade fair in Las Vegas during January 2019, we were pleased to catch up with Robert Trout of Lily Corporation. Lily is the world leader in producing specialised equipment for resin injection into concrete structures. BBR Contech has a close association with Lily and we’re keen advocates of the company’s technology. It’s worth taking a few moments to explore why.

Concrete cracks are not uncommon, even in well-engineered structures that are intended to last for decades. In a seismically active country such as New Zealand, they’re a fact of life. The question is what can be done to repair concrete so that it meets acceptable performance standards – and perhaps even exceeds the strength of the original design.

We think there’s a strong argument for focusing on the engineering of the equipment and systems that deliver epoxy resins into a compromised structure, rather than simply treating concrete repair as a generic patch-up job.

To understand why, it pays to look at the history and development of epoxy injection.

Epoxy injection since the 1970s.

BBR Contech was the first company to introduce epoxy injection of concrete to New Zealand in the mid 1970s, using pumps and technology developed in Europe. Since then we have completed many hundreds (if not thousands) of contracts injecting epoxy resins to restore cracked concrete.

Then the devastating Christchurch earthquakes struck in 2011. Post-quake assessments revealed a large number of structures that were still viable but required epoxy injection to remediate cracks. At BBR Contech our workload ramped up, so we decided to investigate the most appropriate long-term solution.

We recognised that our epoxy injection technology needed updating to enable this large volume of work to be undertaken to the highest standard, and this would require using the very best equipment available worldwide.

Purpose-built for precision injection.

We already knew of Lily Corporation as the market leader in automated epoxy injection machines specifically developed for that purpose, rather than repurposed from other industries and adapted to perform epoxy injection, as many other systems are. Lily is focused on producing equipment and consumables to provide the very best outcomes for end users. So we reached out.

Lily reacted very quickly to provide us at first with two of their CD15 pumps, later increased to six pumps to deal with the enormous amount of injection work in Christchurch following the quakes. The pumps are now located in Auckland Wellington and Christchurch.

BBR Contech’s CEO Derek Bilby with Robert Trout of Lily Corporation at World of Concrete 2019

A better system for better results.

How exactly does an injection that’s custom designed for epoxy injection into concrete ensure a better outcome? It all comes down to good engineering.

The Lily pump’s unique metering system ensures the correct ratio of resin components every time. This means the resin always cures to the desired mechanical properties. In addition, the automated injection process requires less operator intervention to obtain a quality injection installation of full penetration of cracks down to 0.05mm.

Lily equipment is produced using high quality componentry, ensuring reliable operation for many years. The basic design has been around for 40 years with continuous improvements over that time, culminating in the current CD15 model we use.

Last but not least, the Lily injection system is engineered for optimal performance with Lily consumables. The company produces a range of epoxy injection products that are tailored to make resin injection effective in a wide range of real-life situations. For example, Lily offers a corner surface packer that allows injection of cracks located in a corner.

Building up our strength in concrete repairs.

The partnership between BBR Contech and Lily has advanced in leaps and bounds since we first imported their equipment in response to the quakes. Notable BBR Contech concrete repair projects since 2011 include the following:

  • 2,400m metres of crack injection on the Napier wharf deck;
  • Five years of injection at Canterbury University – various buildings;
  • Three years’ work at Christchurch Hospital – various buildings.

In an ideal world, cracks would never appear in concrete. As every concrete engineer realises, they sometimes do. This is why an epoxy injection system that’s custom-designed to work with specialised resins and concrete remains the gold standard in concrete repairs.