David Hughes

David Hughes

I am a chartered civil engineer and academic based at Queen's University Belfast with consulting experience in geotechnics and pavement design on road construction projects across the globe.

Location UK


  • yes - there perhaps ought to be integrated design between flood routing and embankment design in this case.

  • thanks for participating :-)

  • Yes - this was the intention - but CV19 stopped us meeting - apologies.

  • I think it already happens there.

  • The chemistry of and rheology of bitumen is quite complex and outside the scope of this course. In simple terms bitumens have different rates of softening when heated (called temperature susceptibility) and this susceptibility can be reduced by the additions of polymers to the bitumen ie 'polymer modified bitumens'. You could 'google' this?

  • Hi Margaret - this depends on the type of bitumen used in the road. Some bitumens can resist high temperatures better than others. Temperatures can get very high on the black surface of roads!

  • Thanks Margaret - have you a link we could use to view it?

  • thanks - lets hope they start to recognise climate change impacts in your area soon!!

  • Thanks - you are certainly in an extreme geographical region!

  • Great to hear from you all - hope you enjoy the course.

  • thanks :-)

  • Did you manage to get the info downloaded?

  • Absolutely agree - thanks for this.

  • Thanks - this is useful for those at an experienced professional engineer level who want to carry on and look at other alternative approaches in greater depth. Our aim here is to introduce the basic concepts and create an awareness of the subject.

  • Although this is not always possible to do.

  • Yes - these low lying islands are very vulnerable.

  • Many thanks - it was an interesting course to develop!

  • Thanks :-)

  • That's great news Peter - thanks.

  • I agree in theory - but this doesn't always happen in practice and planning rules are often not strictly adhered to in this environment.

  • Thanks - very useful!

  • Yes I agree - it's a very important part of the transportation network but sometimes overlooked.

  • Interesting approach - although might be a bit too complicated to apply?

  • Contact ReCAP directly?

  • http://research4cap.org/SitePages/ASCAP.aspx see this page - ReCAP only has research ongoing in these countries.

  • Nigeria is not a 'ReCAP' country - see http://research4cap.org/SitePages/AFCAP.aspx . However the learning will of course still apply to LVRR in Nigeria.

  • @LornaAllen Hi Lorna - the course is aimed at low volume rural roads (LVRR) (often unsurfaced gravel roads or earth roads) in developing countries. These roads are often the only access to large rural areas. We are not really talking about country or secondary roads in the UK where we have alternative (relatively) high quality roads to service agriculture...

  • @RobelDesta Thanks - can you give us any links to the URRAP so we can see what you are doing? Sounds interesting!

  • Hard to stop some slope failures in Nepal - it must be an expensive road network to keep open when compared to the roads in the Terai!

  • Thanks for this.

  • Yes - terracing and planting can be a great bio-engineering solution. If done carefully it should be a positive thing - I guess the thing to look out for is to ensure you have good draining detail on the terraces.

  • Thanks for all the contributions here - lots of great answers given. Particularly interesting is thinking about all the impacts if a route is closed and barely passable!

  • @MarkHenry Thanks Mark

  • Thanks!

  • Yes - I guess it about having a plan to deal with what might happen to a route. There may be many alternate ways to repair/rehabilitate a road - or to accept that there will be times when some routes will not be passable. Hopefully the course will allow people to think of a variety of solutions.

  • Pretty much :-)

  • Yes - the terrain is particularly challenging in Nepal!

  • Yes - rainfall patterns seem to be changing. Hard to imagine the effect of living in a community that is so isolated from transport for such long periods of time.

  • I think usually these decisions will be made at government level - and as engineers we will be asked to design for a particular scenario. Nonetheless it is good to have some knowledge of the variability and uncertainty involved in taking these decisions.

  • Yes - I think of this as the difference between 'weather' and 'climate'. Weather is very short term - and can be very unpredictable - climate is the longer term 'average' trends measured over decades or even centuries.

  • @AbdurRahman Yes - I've often thought about this - the more we 'develop' the more we possibly emit GHGs. I guess we have to move towards a greener economy generally, but I think we still need to provide good access to remote rural communities - for health education and for access to market.

  • Hi - welcome aboard - hope there is something in the course for you - and you can contribute your knowledge to this learning community.