moveDVDC
Pierre HORNYCH (Univrersité Gustave Eiffel), Rodrigo SIROMA (Colas), Mokhfi TAKARLI (Université de Limoges), Bertrand POUTEAU (Vinci Construction), Léo COULON (INSA Strasbourg)
The National DVDC Project ( www.dvdc.fr) organized a day of restitution of its results on Tuesday, November 7, 2023 at the ENTPE (Vaux-en-Velin).
Work on the National Project “Pavement Service Life” is drawing to a close. It provides answers to the question of pavement distresses mechanisms at the structural and material scales, as well as their diagnosis at the network level.
The partners of the PN DVDC presented the main results and conclusions of the project. 210 people attended the day, in person or remotely. You can find the replay of the day as well as the presentation materials in French and English.
I think we can come back I saw some reactions on your presentation this is done in a very factual way but were levels of strong cracking doesn’t doesn’t really um question the validity of recycling but it’s a point we it’s something we have to monitor carefully and they’ll have a significant is the
Movie DVC which was funded by the national Agency for research is a team that’s going to give you some results P Nish in particular who was the uh leader of the Hiner move dvdr move dvdc go the various people he’s naming so several people who will present these results good afternoon
As Simon was saying we’re going to try with several speakers the move VDC project with very little time so this will be an ex extract of results I’ll introduce first it was a linked to the problem of the mechanisms of course and the materials the idea of project was to better evaluate the
Mechanical performances and the residual um life cycles to try and evaluate their residual life cycle and we decide to limit ourselves to uh the uh set materials because often we had the layers with uh um more traffic and toed the residual and uh we’ll see what’s uh how we can calculate these for
Residuals we try to look at the mechanisms of aging and mechanical aging and to look at the studies and I’ll explain the programs for Aging for the materials on the SES so there’s no comparable of life cycle so there’s no English slide sorry about that so it was a
Collective project that had eight Partners four academics gavel University of liage USP and insa in stasbor and four Partners companies total energy V vas construction Aria I always say ovia and the the parts that we know well if so there were six tasks three of some which was
Transversal and some was for the uh the analysis with sampling that was done to characterize coordination and evaluation and three tasks more on the experimental tasks 14 and uh someone the analysis on the covering the experimental program was at several levels there were laboratory studies on materials made in
The Laboratories and some that were you chosen from on site we had one bond which is 3550 which is pure and modified and two types of granulations of one was limestone and we had three types of Aging the Aging of bamans that aged in the laboratory then asphalt mixes that
Were expanded in the laboratory with a procedure with that was the relim procedure and the Aging of materials that were in service in three cases we looked at the bonding elements the characterization both physical chemical and rological and for the uh we did this for the uh asphalt with the mechanical for modulus
Fatigue water sensity and all nondestructive monitoring Associated to Mechanical tests for the aging process for the bonding uh we had three levels fot1 plus two pav cycles and we also had new bonds and in laboratory we use the procedure for aging that proposed which has four hours of aging and
135° and several days of uh aging at 85 Dees so we did to two five and in some case nine days and even 20 days which is not on the slide and then we we had we extracted things from four sites you can see this on this slide on this sites we
Used asphalt between minut B with medium to heavy traffic which were all about 20 years old and the structure was made of GB3 and we also showed some that were low to medium damage but in those cases we can see at a residual uh lifespan if it’s completely
Uh uh damaged we don’t have any residual uh life span and we did something else uh we did went to areas of circulation and non- circulation to have the effect of aging and traffic in non- circulation either we went to an area for a uh a an exit
Where there were no vehicles yet or outside when it was outside of uh areas that you could actually drive so we took sites with different climatic conditions one site in non which is in Strasburg on A35 in in dja on a departmental road and a s near M on the departmental road some
Were chosen with Partners from the of the project which whom we’d like to thank for giving us the possibility of studying these materials and you can see the samples that we took were quite big so we could do both the bonding and the the uh Pavements so these were big uh
Samples 60 cm on each side on the entire uh thickness which were then cut into smaller samples the uh trials that we carried out we I’ll conclude with that for the bonds we had on the binders we had character during tbba fraction s fractions different calorimetry scanning DSR Metra Vib and infrared
Spectrometry and we were very interested in the rology of the Bindings that were aged at for the uh bindings as well as the uh actual materials and the asphalt mixes there’s quite a lot of data that we can use for the mix behaviors these are very um complex fatigue uh resistance to water
TSR yes local temperature cracking visualization by impregnation in certain cases to see what damage there was to the material and there’s also a study which looked at complimentary mechanical test with ultrasound measurements or acoustic emissions to get more uh information on the state of the materials I’ll finish
Off here and I’ll give the floor first Rodrigo seroma which who will talk about the study of the bindings afternoon rri Found You The my thesis results my thesis at University G and the the asphal complex with Metro which is an IM type dma type things with attraction and
Compression at low temperature and high temperature as well with 15 to 20 60° energy then we went 1 to 80 hertz frequency and a person ratio of 05 so G and and then we have the iso which we we created the unique curves bit on a reference point
Which allows us to show is at a frequency level that’s higher than what we get in the laboratory and the rical model was the beretto and on the right uh you have on the left of the module and the long phases mt35 at the different levels of Aging which with
Aging there’s an increase of the modulus and a reduction of the under phas we also tested some criteria for the end of life in the literature like uh Point criteria which are calculated in very accurate set the uh Glover row which is done in at 0.5 per sections uh and 15°
Celius and then you have go to 27 and 45° at 7.8 Hertz which was proposed in France in the ’90s in this type of criteria we have a zone of the asphalt where is not it’s not doesn’t have as much cracking you can see these are the blue
Areas and with aging we have the new asphalt who goes towards the red area where it has greater sensitivity to older cracks in the literature there’s the discussion on the type and that’s what I want to explor my thesis so we chose the phase the phase length and we know that
It’s through for the chemistry and the micro structure and this curve means that the Curve uh flattens with aging so the question at what frequency do you have the most significant change in the phe multivariate statistical analys was used and in this case in master curve of each asphalt mix was
Characterized by eight values that was well well distribut which uh she gave us 59 BS with the eight phase angle values with eight columns and the Aging level it gives us this 2D representation just move forward a bit represent 97 96.7% total variation of this database
What you have to keep in mind is that the axis are no longer the initial but linear combinations of these variable in initial variables so just to show you that new asphalt goes here are all on the right they and go towards the left with aing and we see this
Inflection for each of the asphalt mixes this analysis allowed us to show that 85 10 at at minus 6 which means that the we could to put this in the um small um size samples for the degree and then we had a hierarchical clustering correspondence which allowed us to have
Two clusters where on the right and we compare this the grover row Criterion and in the first cluster you have all the asphalt mixes that are not non cracked and then this second one on the left you have some that considered non crack but otherwise that are in the
Danger zone and asphalt mixes who are more likely to be cracked so the question we asked is what is this frequency what is what is the reason for this frequency during the NIS and with this frequency look the the Delta method used to simulate the apparent molecular weight distribution based on the rology
And to illustrate that you have the four main curves of of P 35 and this is what you get on the on the on the dalon method the blue curve is the attribution of new asphalt and red is the oldest what we observe is that it increases of the large molecules
Compared to the small molecules there’s the trans transformation of molecular mass towards the greater size molecules and this appearance of new molecules so the the Delta method given by the PCA corresponds to 15500 G per Mo M Mo which means then two molecules of as 10 so
Here we have a representation and of a molecular glomeration to quantify we proposed the molecular glomeration index the Mii which is the ratio between 1,500 by m that to the total and om is varies by 1.5 and it increases with aging so you can see here
Is asphal mixes that are the old uh expanded and this is shortterm aging and this is L 259 till 20 days at 85 Dees C there’s a constant increase we also calculate the coefficient variance for the measurements between different two Labs with two different reters and we
Looked at the Mii compared to gr there’s a variation that’s L this Glo row given that the M showed good correlations between end of life than what was presented before we we we have Pro proposed threshold value temporarily M have 58 and you can have also V visco analysis if you want to
Test so then then now we have the thermal stress restraint specimen Cedric represented that to a certain extent and the idea is to evaluate the resistance of very low temperatures for the asphal mix which has been subjected to controlled Cooling and with and not allowing it to shrink so it goes from
From the ambient temperature towards the cold and there’s an increase of the cryogenic until we get a Breaking Point and this it shows the fragility level of the asphalt mix and from this we can uh recover the uh the Aging level and we can see it that higher temperatur the uh
Uh which is no longer the case let see here with the accumulation of the constraints means that we get um a breakdown so we could observe with the uh asphalt mixes that were uh used and then compacted in the Aging there’s an increase of the breaking point and uh
And we saw on the blue is the the U just after having made the uh asphal of black is the uh Aging for five or nine days in red we see that as far mix can relax more at the beginning of the uh trial in not the asphalt mixes that we
Characterized was a t tendency that we didn’t expect a trend that the uh the foundation uh level aged more than the higher levels that’s we have a temperature here which is uh Which is higher than the B than the base and so we have we also tested the asphal mixes around the
Foundation and circulated non circulated zones in D but we didn’t see much difference we also compared the Mi M with uh the the brake and the uh constraint and we look we looked with the we see the that there’s a good correlation between uh the compressed as and we see this abrupt uh
Increase and a fra and a break when we go near to the 5.58 threshold we only have 10 samples so we can’t uh we would need more to validate this the some a few conclusions for this part of the testing the phase angle Master curve combines the high
Sensitivity of the phase angle with the usefulness of the master C which allows us to extrapolate laboratory tests conditions which allowed us to use multi multi stastical like like PSA PCA and shows us the frequency for the uh the phase length with aging and with its frequency and looking at the Delta
Method we were able to show the molecular glomeration index which quantifies the reduced frequency determined by the PSA and we were able to show a temporary amount and the Mi has a good relationship with the uh material and that’s it for me thank you good afternoon I’m re researcher in Lio in
The gluton there’s a few colleagues who presented earlier I’m presenting the characterization of advanced CND D is which was done as part of T task four and the ceas which was sustained in 2 and there was some experimental work and model modeling which will presented by n right later
On this work began in June 2019 with the organization of an workshop and during this workshop for two days the participant ANS were able to uh attend a CND specialist and experimental workshops and the methods that were presented was ultrasound impact response with models that are associate acoustic emission
Image correlation infr red tomography and color color integration these are techniques made in the lab and yet we also looked at methods that used in on site which and mww d and then we you because of the MLS we presented this to the participants during this Workshop we wrote two deliverables which an
Overview of which is in realm the state-ofthe-art was looked at the overview of ma passive and active seismic n in asphal in Asphalt Pavements in on site for asphalt mixes and another deliverable which was uh trial forms which shows our partners what methodology has to be used to
Integrate the CND methods for the enrichment of conventional trials such as fatigue or modular complex trials for the ultra sounds which means that you have Micro vibration that is propagated the material we worked on how to come back for the point we we worked on blocks that we took on the four sites
We talked about before for each of those sites we took blocks of circular culation not circulation zones and the work began by separating the base and the foundation so they got 400 by 600 mm PLS and this materialized a grid of 5 cm and it was propagated in the compression zones and
The shearing zones with a frequency of 54 kilos for compression and 40 Kilz for the uh shearing and then we vary the frequency of the vibration and the intensity to uh play on the SNR that was very interesting points because we were a we are talking about materials that are
That are damaged we want low snrs but the idea is to show what we can have in the uh the notion if we don’t uh Master SNR so so we Define a threshold under which it’s not really relevant to have ultrasound propagation so once we’ve worked on these different methods
And we move on we’re able to map map out in relation to the shearing effect and we associate this with uh volume mass and take we take into account the gamma densimetry using all the calculations we’re able to obtain this kind of of mapping out of the elastic
Properties um there on the screen what’s important is that we know how to obtain these mechanical properties using three methods if we consider an elastic isotrope material this is what we did here we can have visco elastic Isotopes so we just have to add the speed but we also know how to guarantee
Propagation using a visco elastic uh material because we work for example on wood um but we cannot just limit what we do to a specific isotrope model so what do we do with these modules we then place them on top of each other um where we have complex
Modules so that we can analyze the relevance of the results that we’ve obtained just one extra detail the mapping process is very interesting in that we can analyze the harmoniousness of our plates before we then take samples to do to do the tests also in addition to this what is interesting is
Here you can see that we highlight for the djon site that there’s a big difference um between the circulated layer and the non- circulated layer in other words the layer where there’s a lot of traffic and the layer where there’s a not and then you’ve got in terms of the dynamic
Elasticity we’ve got a drop of about 20 gigap pascals so in other words it means that ultrasounds are a good tool to use if you want to analyze the high frequency elasticity and if you want to uh take it take into account the high or low levels of traffic another point this
Type of discrimination was a lot more relevant for the base layer but it’s less relevant when we’re focusing on the subbase layer uh in this case the difference is relatively low another point that is highlighted This concerns the isotropy of the materials the anisotropy sorry um we performed the analysis as you can
See on the screen and what you can see here whether it’s for e or G is that we have the XY axis and you can see that in relation to the XY aises we have this the same values and these are results that are pretty well known in the bibliography and we’ve simply
Highlighted this for our materials the next question was it’s all very well to determine a module using ultrasounds but is it as relevant as all that we decided that we would um compare the two pieces of data on the left hand side you’ve got the data sorry I’ve moved ahead too quickly
On the left hand site you’ve got the data for djon the samples that we took on the site of djon and we compare the impact of the assessment method and we see whatever method we use we have good compliance between the high frequency module and the mechanical module on the
Right hand side we applied a principle whereby we looked at the temperature and the ultrasound data um this this time round we used a visco elastic approach we had to work out the attenuation coefficient and we can see that it works quite well you can even look for module
Values that cannot be reached by the mechanical values the second part This concerns the acoustic emission this is just about recording the micro noises um that can be generated by the materials that are fracturing um whether there were mechanical physical causes whatever the mechanism were able to record the fatig
Process um record the acoustic emission so we performed a fatigue test and the first difficulty we were up against was identifying the different type of transductors that we could use from an electrical perspective in terms of the frequency in terms of the size of the transductor for example once we’d worked
That out we launched into the test and we ended up with a very sizable database at the end of it on the left hand side you’ve got the mechanical data on the right hand side the um the acoustic data um and from an acoustic perspective we have about 17 parameters the idea is
To then identify criteria or specific points in terms of the temporality of the fatigue so that we can state that something is happening at a given moment in time in a specific location when it comes to acoustic emission when we look at the time frame for the acoustic
Emissions we can see there there are three phases the first phase is the activation of a pre-existing defect in material that’s already been damaged then the second phase corresponds to the creation of the mechanical damage and the third phase is the fracturing or the fracturation phase it’s important to
Note That acoustic emission can be represented from a spatial perspective or with XYZ recordings of events and to this you can also add the energy based intensity of the of the events and this brings me to my last slide at the end of the day if we
Compare all of the criteria that we obtained there are three types of criteria you’ve got those damaging criteria that are acoustic criteria that’s in red next next we’ve got the damage criteria that come from postprocessing of the mechanical data I didn’t mention this before in fact we introduced um a mechanical data fitting
Process to remove all the parasite noises and this led us to a fate type function level 8 fora type function and based on the continuous function that we obtained We performed a basic mathematical operation with uh derivation to come up with global minimums and maximums and that meant
That we had all of the criteria that are in blue and in green you’ve got the standard criteria that are based on the loss of the modules or the energy criteria at the end of the day our conclusion is that thanks to this acoustic emission we’re able to identify
At least the beginning of damage the start of a fracture and this is correlated with new mechanical criteria criteria that we’re able to obtain solely thanks to um the filtering of all of the parasites in relation to the the data and in terms of the Outlook we’ve
Heard a lot about different aspects um different tests here you’ve got the first illustration of the types of tests that we’ve performed other operations are underway and I think that in the future if we talk about listening to the acoustic emissions in this kind of test
I think there’ll be a lot of conclusions we can draw thank you for listening a okay thank you very much um we’ve been put under pressure by the director we’ve been told to told to move ahead very quickly I’m in charge of the construction sector and I’m going to be
Talking to you about an organizational point in our work in other words as you know um we’ve talked about it a bit we’ve had a lot of work to produce experiments in Leon over 60 material configurations when I talk about material configurations I’m talking about where they come from and they’re
Aging we’ve presented a lot of these aspects on the level of the asphalt mixes as well we’ve had about 20 configurations for different types of materials and you’ve seen different experimental methods as well next in terms of our organization in the anr we work with our partners in a very
Balanced way we’ve had seven Partners who’ve worked with us on our experiments notably for the laboratory manufacturing part we had a bottleneck for um building the asphalt mixes and so that we could then enter into the process of identifying the binders or the asphalt mix so all the partners who’ve
Contributed are going to be called to come and stand here afterwards and let me just say that this work has been ongoing since 2017 and it came to an end in 2022 so we put together an experimental database and before going back to the technical side with Leo I
Wanted to talk briefly about the organization the aim was to Simply facilitate access to the information for all the project stakeholders during the course of the project also to standardize all of our data exchanges that’s important for example right from the outset we wanted to list the rules
That we would abide by for exchanging information we had a nomenclature at the beginning of the project also we decided to define the different deliverables that we were looking to achieve so that we’d be able to compile indicators further down the line and of course what
We wanted to do was divine the test results that we wanted to be able to present in the database of course we want to facilitate um usage above and beyond the project and this is something that has been done thanks thanks to the feedback for the M project we wanted to
Make available a database for both binders and the asphalt mix and we wanted to be able to compile 100% of the results not just the IND ators but also the minutes the tests and when necessary the raw data for the tests we wanted to make sure that all of this would be made
Available regarding the last Point um what we wanted was for the modelizers to be able to find the the information they needed to qualify the models and more often than not modelers um find it very difficult to gain access to the data that is of use to them often it’s the
Same data that is used over and over again I’m not going to describe the database in detail I’ve just talked about the philosophy that underpins it it’s an Excel database one for the binders one for the asphalt mixes then we guaranteed that there was a correlation between the different scales
Of course work still has to be done on this um for a given given approach you have information on the binders on the left and then the asphalt mixes on the right and then we compare and cross compare all of the different pieces of information um we’ll also as I said make
Available the raw data plus the machine files when I say machine files they tuned slightly so that users can interpret them and at this stage let me pass the floor back to Leo who’s going to continue I apologize for having rushed through that so in terms of the
Assessment the results we launched this project pretty late on uh virtually Midway through we should have launched it a lot earlier I really do recommend to those of you who are going to design projects of this type um it’s a very good idea to design the datab base right
From the outset that is what needs to structure the project and that is what needs to enable your colleague um your colleagues uh to be able to work efficiently we all learn as time goes by to work efficiently together we have the cloud technologies that make exchanging
Data easier and it means basically that we can start to work more efficiently and work in a crosscutting manner with the modelizers so my name is Leo kulan from insa Strasburg during the course of my PhD thesis I focused on um Aging in creating a model for the aging process I
Wanted to look at the different effects of the aging process notably for the Cal plane that you can see on the left hand side I wanted to look at visco elastic aspects um nonlinearity um self-heating for example um visco elastic Pathways and we look at all the other mechanical aspects such as
Porousness um um and these are all important within the scope of the Cal plane I developed a model that I call the venol model um it basically takes all the variables into account in order to go through all the visco elastic effects and we look at the viscosity and
You’ve got the different equations that you have on on the screen and then we take into account the other visco elastic effects such as the temperature the deformation amplitude uh and thixotropy and we create equivalences you’re all familiar with temperature equivalences we simply establish uh principles that work for
The other aspects and to this I added um an extra law for damage you have this at the bottom of the page and this this means that we can invent fictitious crack for example and then we apply the Paris type law and you calculate the corresponding value of
Damage so that we can then create the damage law uh for the model next I’ve included a few examples I’m not going to present them all in the top left hand corner uh you’ve got the example of where the damage becomes predominant you’ve got examples of fatigue at different temperatures
Um you haven’t necessar necessarily got the structural effects but at least you’ve got the temperature effect and on the right hand side you’ve got digital modeling that was carried out in the top right hand corner you’ve got the impact of paracity if we reduce the paracity
Then you get more rigidness and in the DM test we obtained the results that we expected concerning uh porousness using the col Cola approach and in the bottom right hand model you’ve got fatigue tests at the level of the phase angle in color you’ve got what we obtained with
The DM and what’s interesting here is is analytically speaking the damage can’t be seen on the phase angle because you’ve got the real part and the imaginary part that cancel each other out but um digitally speaking we have a curve and you can see where the curve
Increases this is where you’ve got the pink cycle that illustrates that it is well and truly there next in the third slide we will we look to Define resources the wherewith all to define the level of damage um on of a road pavement notably in the test tube that
Way we can then use the ratio that we applied for the test in order to evaluate the extent of the damage in the field of course it’s important to take the aging process into account if we want to have something precise and if we’re not fam if we don’t have the data
On the new on the state of a new road pavement we can use empirical data in other words a damaged Road Road pavement uh will we can apply certain types of data um and once we have the data we’ll be able to predict what is likely to happen on another new road pavement
Rather than waiting for the later phases of the damage before we see that it’s the case and on the fourth slide we also work to a certain extent on the aging process here we used um data that we had from a project for the aging process we
Saw that if we looked at the different moments where the Aging took place we could find correlation between the model parameters and so thanks to this we saw that we could come up with a method in order to notably model the aging process for visco elasticity for example I
Haven’t presented the results for fatigue for fatigue it’s a bit more complicated because we realized that um aging seems to impact the evolution kinetics of th thot Tropi and damage and so if you study um an asphalt mix that is aging you have to study all of the parameters which would be
Counterproductive here that’s all I wanted to say for the modeling part of my thesis the next uh slide and let me stress that I worked with sofan also on the thesis and he focused more on the thermodynamic approach so he modeled phase one starting out with dissipated energy and
He went on to model the damage with an incremental rate based on the energy the energy that was measured and his modeling was heterogeneous so he showed the bitchman and the granulate as you can see on the screen where he was able to separate the real part and the
Imaginary part and on the right hand side you’ve got the results of the simulation that he found in blue you’ve got the curve without damage and in red um the curve with the with the damage so that’s all I wanted to say for my part and I’m going to pass the floor
Over to Pier for the end thank you very much given the fact that we’re totally lacking in time I’m going to conclude very quickly just to say that we’ve presented just a few extracts to extracts on the work that has been carried out there will be a
Feedback day that will be organized for the Hina project we haven’t yet set the date but we believe it will be at the beginning of 2024 now in terms of a few conclusions we’d like to draw for the binders we’ve studied different aging methods in Laboratories we’ve had the rtfot test
And the pav test and we basically realized that at the level of the materials the rtfot and the pav aging processes they’re quite severe and the Aging that we had in situ was between the rtfot levels and the pav levels so the Aging levels for the binders alone I
Would argue uh quite limited the aim of the work is to come up with criteria so that we can better describe describe the binder aging Rodrigo presented a solution to you and this gives you an idea of the molecular St structure of the binder that can indicate the aging
Process and as was said there is software that is available free of charge online that is called visco analysis this enables you to calculate the main curves for the binder to calibrate the real ogical models and then to continue so those of you who are interested please feel free to use it um
For the for the different binders to see what the results are and we’d also simply like to confirm this criteria that Rodrigo presented um that seemed to indicate a level of Aging that is more considerable for the binder next concerning the asphalt mixes we haven’t presented everything but we did propose
A certain number of methods that make it possible to distinguish between aging and damage notably for the test tube that you saw all we’re able to compare what what we call um altered materials and non-altered materials we also worked on protocols for on-site sampling and the production of laboratory samples of various shapes
And sizes as you’ve seen there are different testing methods that have been proposed or that have been described you also saw the development of innovative tests in order toi to define the damage and Fracture phenomena all of this can be applied to site samples and laboratory produced materials and we
Also have uh a better description now of the evolution of mechanical properties with the aging process notably we saw that the types of fatigue curves can change quite a lot depending on the aging process depending on whether we’re talking about phases one or two um fa
You have phase two and even phase three where the the change process is a lot faster we’ve also noted that the aging process has a very strong impact on other Aspects it’s very important to note that the materials age and as they age they become more rigid uh this is as the binder becomes uh older it it means that all of the road pavement becomes harder I’m afraid the gentleman is speaking a bit too closely to the
Microphone and we can also talk about the aging process of the binder and the mechanical properties of the asphalt mix there is a link between the two and so there are studies ongoing for the different car characteristics of these two there was also the modeling process the work that was carried out by
Stratsburg notably and this made it possible to develop a model that in turnone makes makes it possible to um describe the behaviors from a fatigue perspective and taken into account the aging process as well above and beyond all of that beron said it’s very important to have
Databases um to focus on the binders and also on the asphalt mixes and these databases need to be used above and beyond the project and then of course there are all the additional analy analyses that are going to be performed we’ll see in what context this work can be done
In particular relating to the behavior of the binder and the different characteristics the different behaviors also of the asphalt mixes so there you have it we hope that um all of this was of great use to everybody just a few comments I believe that all of the data
Is going to be available we focused on three themes there have been quite a few Publications seven articles the articles are on the screen with the sub um the binders the modeling process and also the asphalt mixes there you are I’ve concluded my presentation and I do
Apologize for us run running over but we did desperately want to try and present several subjects and do so within the space of 40 minutes so thank you very much