Impressions from a UHPC conference in Albany, NY
Frederik and I attended the 2nd International Interactive Symposium on UHPC, which was held in Albany, NY in the beginning of June and in this blog-entry I will relate a few of our experiences. I had also attended the first symposium in this series. This event was held in Des Moines, Iowa in July, 2016 and the symposium was a pleasant surprise for me with a lot of focus on interaction and discussions and with a very practical approach as a large part of the attendees were contractors. I have briefly remarked on the different types of conferences in my comments regarding the 2017 conference in Montpellier.
After a 3-year break to accommodate some of the other UHPC conferences being held in Europe and China, the organising committee behind the first symposium in Iowa was now ready for the follow-up in Albany (the third instalment will take place in 2023 – hopefully). The symposium had more than 300 participants from 21 countries, including myself and Frederik – a young engineer from our design office at Hi-Con. Frederik is in charge of the design of most of our façade projects and Frederik and I both had presentations at the symposium. I am not usually with others from Hi-Con at conferences, but as there were up to 5 parallel sessions it worked out nicely in being better able to cover all the interesting presentations. It was Frederiks first conference and he was very enthusiastic about everything. I am usually also on the enthusiastic side (but I am toning this down as I am getting older), but it is funny how as Frederik was being young and enthusiastic my immediate reaction was to act as a counter-part to this and slip into the unbecoming role of “grumpy old researcher”. When he would show up and say things like: “We should really try these carbon nano fibres – they should be able to increase performance by 55%,” I would respond with something like: “It will probably be too expensive” or “We tried that in the early nineties”. Fortunately, however, I realized how ridiculous this sounded, and I was able to catch myself and tone it down a bit. After the conference we are actually trying a few things out that could be useful. In this regard the symposium did not disappoint – quite a few of the presentations were very practical, as UHPC is now being used by many people in lots of projects and they are ready to relate their experiences. This is perhaps mostly aimed at people that are relatively new in the field, but new input (or new angles) is always nice as it gives us a chance to rethink what we have been doing and look at it from a slightly different perspective.
More infrastructure than architectural
The keynote presentation at the symposium – by Hauke Jungjohann from Buro Happold – dealt with architectural applications. Also, two sessions and a panel discussion were devoted to architectural applications of UHPC, but only a few projects were presented – including a few Hi-Con projects that Frederik presented.
Other than that, the emphasis of the conference was on infrastructure applications – bridge joints and overlays. An overlay project will require a much larger volume of UHPC than a jointing project, but the ABC (Accelerated Bridge Construction) system has been used for nearly 300 bridges in North America now, and for some of the bridges it is really a substantial volume of UHPC that is used. E.g. for the Pulasky Skyway in New York, a total of 3,800 m3 of jointing material was used. I have included a link to a FHWA Technote on overlays.
Frederik presented a few recent projects in the first session on architectural applications.
In Europe we would see a lot more architectural applications and fewer infrastructure applications – although a few overlay projects in Europe were also presented at the symposium, such as the Chillon viaduct and an overlay project in France presented by Guillaume Roux of Vicat. Apart from the different applications, other themes at the symposium was design, material properties and guidelines and standards.
Technical visits have often been included after a conference as a separate package, but at the two symposiums in the US, they have been an integral part and this was also taken up at the last UHPC conference in France, which took place in Montpellier. It is a nice break and increases interaction between the participants when it takes place in the middle of a conference rather than as a post-conference tour – and as there are more and more UHPC applications it is getting easier to plan these tours. In Albany we could choose between 5 different tours. Two of the tours focused on different bridge projects and a third was very hands-on with UHPC technical training, but Frederik chose a tour that included a visit at the Fort Miller precast facilities and a demonstration tour of UHPC. I attended the 5th option – a visit to Rensselaer Polytechnic Institute where we were shown their lab and research activities. As part of the visit we also had a demonstration of six different commercial UHPC products – and got to cast small specimens ourselves. Demonstrations were by Ductal, Dura, Steelike, Kings, Cor-Tuf and Aalborg Portland. Other types of UHPC that were presented at the conference but were not part of the demonstration were Smart-Up (the product by Vicat), TAKTL and CRC (the UHPC used by Hi-Con). In order for the participants at the demonstration to be able to take home small samples, everyone had cooked up a mix heavy with accelerators, so that we could cast in the small moulds provided and then remove the specimens after a few hours with a reasonable strength. This did not work well in all cases, so the consistency of some of the mixes was more like Play-Doh or chewing gum, but we managed. I have included a picture below and others are available here.
Making samples with Dura – casting would not really be the right word for this 😉
A student competition is quite common in connection with conventions or conferences in the US – perhaps because the ties between industry and universities are closer than in Europe – and of course one was carried out for the Albany Symposium (as for the Iowa symposium). It is a fun way for the students to get a taste of the field and it is certainly something that should be encouraged for European events also. The rules for this particular competition are shown here.
7 University teams (from Asia, South America and North America) made the finals of the student competition and participated with a poster on the first day of the symposium. During the technical visit their beams were then tested in bending. It was not only the goal to reach the highest strength, but the teams should reach the highest strength within a specified range. Points were also given for being able to predict the final strength as well as possible – and complying with all the rules set out for the competition regarding mix composition,m fibre content, rebars etc. As shown below, even within these rather strict rules the teams came up with very different interpretations. The prizes for the student competition were awarded the same evening at the Gala.
Some of the test specimens after they were tested to failure in bending.
UHPC Innovation Award
The symposium also presented two awards for the most innovative UHPC projects in Building and in Infrastructure – and the Korea Institute of Civil Engineering and Building Technology won both. I have not been to any of the sites myself so unfortunately I don’t have pictures – but I have provided links to pictures of both projects in the following (since I am not quite sure I can just include pictures taken by other people in our blog). But the projects were extremely impressive – the Kosmos resort for the building award and a bridge leading to Legoland for the infrastructure award.
UHPC Entry bridge to Legoland:
At the symposium interaction was encouraged as I have mentioned a few times – and to facilitate this a number of panel discussions were included, where the audience could use an app to pose questions – and everyone could then vote on which questions should be answered first. A total of 5 panels were set up during the symposium, covering subjects such as UHPC codes, Architectural UHPC, Modelling challenges and a look at the future. These panels were quite interesting but unfortunately, they coincided with presentations as they were one out of 5 sessions that were carried out concurrently. It was already difficult to choose which session to attend – and subsequently which presentations should be left out – and the panel sessions made the competition harder. In my opinion there were too many panels and something like two would have sufficed. I would expect panels of this type to really provide the latest information as well as giving an overview of the field and this wasn’t really the case in all the panels.
I briefly touched upon the issue of standards and guidelines for UHPC in my earlier post “Do we really need another UHPC Guideline”, but not too much new has happened since then. The French have added two new standards – one dealing with precast and the other one dealing with construction – but neither of them are available in English yet, so I will wait a bit before checking them out. Also the German guideline – which should be very interesting – is close to getting the final approval, and again I will wait until a version in English is available.
For me personally the next conference I will attend will probably by the Hipermat in Kassel in March 2020 – but there are a number of options with UHPC on the agenda – in Hawaii, Singapore or China – so I encourage you (if you haven’t already) to join one of the conferences and be inspired. It should not necessarily be a full conference devoted to UHPC – i.e. the ACI conventions or fib meetings may include a couple of sessions on UHPC so go have a look and ask questions. I almost lost my ability to be inspired – as a counterbalance to Frederik, who is very easily inspired – but luckily I recovered quickly and I am now as enthusiastic about the future for UHPC as ever.
And as always – if you have questions or comments (or just want a bit of advice) – leave a message below and I will get back to you.
Bendt Kjær Aarup