Civil and Environmental Engineering The blog of the Department of Civil and Environmental Engineering at the University of Surrey Fri, 01 Feb 2013 11:21:04 +0000 en hourly 1 Nanoparticles from sources around us! Fri, 01 Feb 2013 10:32:26 +0000 Prashant Kumar

Road vehicles are known to be the largest contributor to the airborne nanoparticles in polluted urban environments. The heavy duty vehicles (HDV; i.e. truck, diesel buses) are known to be the largest contributor of airborne nanoparticles among road vehicles. Other on-vehicle sources of nanoparticles have not got much attention, but our recent work titled as “Nanoparticle emissions from 11 non-vehicle exhaust sources” published in Elsevier journal Atmospheric Environment and highlighted some interesting stats with respect to sources around us. For instance, each km of distance driven by a HDV produce of the order of 1000 billion (~1015) nanoparticles. One kg of fast wood burning produces nearly the same number of particles as for each km driven by a heavy duty vehicle. About 1 min of cooking on gas can produce the similar particle numbers generated by ~10 min of cigarette smoking or 1 m travel by a HDV.”

This full article can be accessed by clicking here to know more about other potential sources of nanoparticles and their dispersion, related exposure and health impacts, as well as state of current policies, guidelines and technical challenges to regulate them.

]]> 0
How Air Pollution Affects Built Infrastructure? Thu, 10 Jan 2013 21:17:50 +0000 Prashant Kumar

We all have seen various structures around us deteriorating because of several reasons. Air pollution, which is known to affect the human health, also play a crucial role in affecting the health of various materials used in buildings and transport infrastructure. Our recent article titled as “Footprints of air pollution and changing environment on the sustainability of built infrastructure” appeared recently in the Elsevier Journal Science of the Total Environment. This highlights the novel links between these cross-disciplinary topics and propose the way forward for mapping the corrosion in an area. The full article can be accessed by clicking here.

]]> 0
Postdoc research opportunity on Structural Engineering Fri, 21 Sep 2012 10:29:00 +0000 Juan Sagaseta

We are currently seeking to recruit a Research Fellow on the EPSRC funded project “Structural performance of slab-column connections under impact and blast loading”. The project will look at the dynamic behaviour of this type of joint regions (Fig. 1) in order to develop a mechanical model that can be applied in design and analysis.

Fig. 1- Dynamic response of RC flat slab-column connection subjected to impact and blast loading

Applications are open until the 29th of October 2012. Full details about the application process and job description can be found in our website (job opportunities).

The postholder will be based at Surrey and will join a strong international team, which includes experts in EPFL (Switzerland) and Arup (UK) working on key issues related to the design and performance of RC structures. A conference paper on this topic(1) has already been submitted and pre-accepted which will be presented at the International fib Symposium in Israel (2013).

Please contact me for informal enquiries

T: +44(0)1483686649




(1) Sagaseta J., Muttoni A. and Fernández Ruiz M., Towards developing mechanical punching shear models for flat slabs subjected to impact and blast loading, fib Symposium Israel 2013, (in preparation)

]]> 0
Water in the news Tue, 17 Apr 2012 08:58:31 +0000 Katrina Charles

This blog was originally posted on the website.

Last month it was announced that we have met the UN Millennium Development Goal for water, with over 2 billion people having gained access to drinking-water since 1990. But do these people really have access to safe water, and for how long with these systems last?

In the wake of the World Water Forum in Marseille in March, water has been in the news quite a bit (sorry, sanitation, you are largely ignored once again).  The big news from Marseille was that the Millennium Development Goal for water has been achieved early (1), with over 2 billion people having gained access to drinking-water since 1990.  That is a great achievement and should be celebrated: consider the number of lives saved; consider what this achievement means in terms of reducing the time spent collecting water; and consider how the reduction in waterborne disease, time and financial costs will free up families to spend more time in education and employment.

But equally let’s not forget the 783 million people who still don’t have access to safe drinking-water (1). Sub-Saharan Africa is one of the areas where many countries have not yet achieved the MDG, with 31 of the 50 countries in that region not expected to meet the MDG in the next 3 years. From 1990 to 2010, the proportion of people with access to improved water supplies in urban areas in sub-Saharan Africa has not changed: slums, and the associated issues of poverty and insecurity of land tenure, remain one of the biggest challenges to providing safe drinking-water, as well as sanitation.

Now is the time to assess the sustainability of the drinking-water facilities that have been built. In order to achieve the aims of the MDGs these water supplies need to be clean and they need to maintained. Thirty to forty percent of hand pumps in Sub-Saharan Africa are estimated to be broken, which is equivalent to “hundreds of millions of aid dollars [being] poured down the drain” (2).

The quality of the water provided by these systems is also variable. The improved drinking-water facilities are designed to reduce the potential for contamination at the tap, be it at a well, spring or pipe, but the actual water quality is not considered in the MDGs. In reality, many of these drinking-water supplies are contaminated, with at least 1.9 billion people estimated to use water that is “unsafe and dangerous for their health” (3).

One of the major threats to water quality is poor sanitation. This doesn’t just mean open defecation or a lack of an “improved” sanitation system, it might include a pit latrine built too close to a drinking-water well, or poorly maintained sewer that leaks into the aquifer, or a septic tank that discharges directly into a stream. To manage this issue there is a need for surveillance of the sanitation and drinking-water facilities, not the expensive and difficult water quality monitoring, but the kind that can be done with basic education about protecting and maintaining water supplies based on a better understanding of the environment in which they are situated.

This progress in meeting the MDG for water doesn’t mean that we can reduce our efforts. DFID spending on sanitation and water is already poor in comparison with similar overseas development programmes (4), but if it is effective it can still go a long way if it is targeted towards education and maintenance (and improving sanitation) to ensure the sustainability of drinking-water supplies.


(1) WHO/UNICEF Joint Monitoring Programme for Water Supply and Sanitation (2012). Progress on Drinking Water and Sanitation. 2012 Update.  WHO and UNICEF. [Accessed 26 March 2012]

(2) Skinner, J. (2012). Clean drinking water is about people, not pipes. [Accessed 26 March 2012]

(3) Payen, G. (2011). Worldwide needs for safe drinking water are underestimated: billions of people are impacted. Originally published as: Published in French in Le Droit à l’eau potable et à l’assainissement, Sa mise en œuvre en Europe, Académie de l’Eau, Smets et al., 2011, p45-63. [Accessed 27 March 2012]

(4) Kinnock, G. (2012) Why has water and sanitation aid fallen even as global aid has increased? [Accessed 26March 2012]


]]> 0
Nuclear is a Trigger Word to the Press and to General Public Thu, 15 Sep 2011 10:11:31 +0000 Rex Thorpe

My colleagues and I were having lunch whilst the TV screens were showing the BBC news one day last week.  The news was coming in about an explosion in a furnace at a nucler installation in the South of France.  The news reader may well have said ‘at a nucear power plant’ but I can’t verify that.  I and my colleagues immediately thought ‘Why would there be a furnace at a nucler power plant?’.  All the non-engineers this bulletin would probably have been thinking either  ‘Surely not another accident at these dangerous nuclear facilities; is it another Fukushima?’ or ‘Nuclear + accident just conforms my view that these things are just too dangerous’.

Those bothering to follow the story like myself and my colleagues soon discovered that our bewiderment was significant.  This was an incident at a facility melting down irradiated metal from a nuclear power plant;  so called low level waste.   The heat needed to melt the metal was being supplied by a furnace using a conventional fuel and there had been a explosion in the conventional furnace as can happen anywhere there is a furnace.  There was very little chance of a leak of dangerous material and the amount that could escape was also small.

On a scale of 0 to 10 where Fukushima might be an 8 and Chernobyl a 9, this was a 1 or 2.  Yes an exclusion zone was set up round the plant but this was precautionary whilst measurements were taken.  It was not really worth reporting on the BBC news, in hindsight, but ‘Nuclear’ is a trigger word for the press.  This means nuclear incidents get over reported and the general public may well therefore get a false view of the number and seriousness of nuclear related incidents.  A newspaper report that reflects both the overreaction and the facts can be found here:

Several years ago I was a lecturer in Chemical Engineering at the University of Cambridge and one of my colleagues won a grant to build the UK facility for the use of MRI scanners to explore problems in chemical engineering science.  Not many members of the general public would think twice about placing themselves in an MRI scanner at a hospital.  It is much safter than having an X-ray or a CT scan both of which use ionising radiation and increase the patient’s risk (very slightly) of cancer.  So why, you may ask ,were there vociferous and emotional  objections to planning permission for this new UK facility that was going to bring jobs to Cambridge and enhance the reputation of the University?  The answer is becuase the correct name for the phenomenon behind MRI scans is Nuclear Magnetic Resonance (NMR).  The people living in the houses nearby to the proposed site of the facility saw the word ‘Nuclear’ in the planning application and knew it must be dangerous.  They were wrong.  What causes cancer is ionising radiation.  We are all surrounded by and made of stable nuclei.  We live in a nuclear environment.  NMR tickles those nuclei.  It does not cause ionising radiation to be emitted.

What is the lesson to learn?

One lesson is that engineers and scientists have to be smart when speaking to the general public.  The medics call their NMR imaging machines, MRI scanners quite deliberately.  They know that ‘Nuclear’ is a trigger word for the press and the general public.  They don’t use ‘Nuclear’ for the very best of reasons becuase it might stop patients from submitting themselves to scans that save lives.

A second lesson, for the press and the general public, is that a proper understanding of certain issues cannot be obtained without effort and time.  This applies in science, engineering and medicine but also more widely.

]]> 0
Canal over River Crossing Wed, 07 Sep 2011 17:15:46 +0000 Muhammad Imran Rafiq

What is our perception of a bridge? We have seen bridges being designed to cross motorways, rivers, and valleys, etc, but mostly to carry the people and vehicles from one side of the obstacle to the other. These are occasionally designed to carry small water channels (known as acqueducts). However, Magdeburg water bridge in Germany have really crossed the boundaries of conventional bridges by connecting a massive canal over Elbe river. It is the longest navigatable aqueduct in the world, with a total length of 918m.

As seen in the pictures, it carries not only the water but also quite heavy boats over the river. Before the bridge was constructed in 2003, the Ships moving from one side to the other side across the river had to make a 12-kilometre (7.5 mi) detour , because the level difference between the two was significantly different.  This massive structure was built using 24,000 metric tons of steel and 68,000 cubic meters of concrete and costs at around €500M.

]]> 0
Defending your MSc or Final Project dissertation Tue, 30 Aug 2011 07:59:17 +0000 Juan Sagaseta

The next few weeks we will be having the MSc oral exams in the CCE Division in which students will have to summarize and defend their work in front of the examination panel. I am sure every person has his own list of tips and “do’s and don’ts” on how to face these type of exams although a viva can go in many different directions depending on your work, the examiner and other factors. We all have heard the typical wise advice of “be relaxed, be confident, be prepared”, tips which might lead to the exact opposite: that would be panic.

What are you best tips for a successful viva?

Here are some random thoughts I had on this based on my experience which you might find useful or not towards preparing for you viva…

  • On the day of the exam you are very likely to be asked to summarize your work and contributions in a short period of time (5 or so minutes); this applies to all kinds of vivas including Final project, MSc or PhD. Remember that before you explain WHAT you did during the project you must explain WHY you think the topic is relevant. Think about the global context of your work and be aware of the practical applications.
  • Often you will be asked to discuss WHY you choose to follow one path or approach over another. You might be tempted to say “I did this because my supervisor told me to do so”. Although this might be true, this could be interpreted negatively as lack of engagement to the project. Instead, you could demonstrate your confidence and knowledge in the area by presenting the different methods that you contemplated and discuss the advantages and disadvantages of each one. This will help you to justify your final choice.
  • In relation to the previous point, if you selected an approach during your project because it was simpler than others, you can sell it in many different ways; for example that this simpler approach would be more likely to be used in practice. Saying that you choose a method because it was the easiest and there was no time to do anything else sounds quite desperate and it might not reflect the amount of work you invested in the project. Focus on the positive aspects and identify the limitations of your work honestly but in a positive manner.
  • If you did not understand a question (partially or fully), don’t be afraid to ask the examiner to repeat the question. This can help you to gain some time to think about it and formulate your answer better. If you still don’t know the answer after the examiner has reformulated the question, be honest but don’t give up too easily. I think it is always better to give an incorrect answer with a certain logic behind it rather than simply give a blank answer. In some cases the examiner might give you some hints; try to grasp these lifesavers as they might help you to find the answer to the question.

Good luck in your exams!

]]> 0
Enlightening and noxious shades of nanotechnology! Thu, 04 Aug 2011 12:05:10 +0000 Prashant Kumar

“Anti–pollution clothing invented” – this was one of the news headlines a few days ago. Well, this is another gift from the emergence of nanotechnology. According to the inventors, “any item of clothing could be treated, but in order for the technology to work you need light. So, for example, you wouldn’t want to coat your underpants”.  Simple but interesting estimates proposed were that if all the 10 million people living in London take one gram of coating out, this would consume 10 ten tons of nitrous oxide in London every day.

If we extrapolate the above numbers, for example, for population and sun light rich countries like India where ~1.21 billion people, and China where ~1.33 billion people, are currently residing and assume that they all take one gram of coating out every day, this could consume ~1210 and ~1330 tons of nitrous oxide in India and China each day, respectively. Let us now put these numbers in the perspective of global warming. Nitrous oxide has about 300 times higher global warming (or heating) potential for 100–year time than the CO2, meaning that nitrous oxide is ~300 times more heat–absorptive than CO2 per unit of weight. This also means that removal of this significant amount of nitrous oxide in India and China, and similarly in other part of the world (making a total of ~6940 tones removal per day), may considerably assist in combating global warming issue. Of course, this is an ideal estimate with an assumption that we all can afford and agree to wear these coated dresses.

The story does not end here. The less exciting part of the story relates to adverse impacts of ‘nanotechnology integrated products’ on  human health and the environment. There are currently over thousands of nanotechnology embedded products in the market and several new products are also emerging every day. We use them on a daily basis. On the other hand, these all are also known to release nanomaterials into the various (air, water and soil) compartments during their manufacture, use or disposal after the usable life. Because of their novel physical and chemical properties, their exposure and release into the environment can have severe penalties on the human health and the environment. Like other things, luxury of making our life better using the nano products comes at the cost of taking care of these products at various stages of their life in a sustainable manner. This topic is open for debate from the perspective of manufacturers, product users, environmental and health conservation community. So, which side you are?

]]> 0
About concrete boats Wed, 03 Aug 2011 17:52:19 +0000 Juan Sagaseta

Can we build concrete boats? At first, one might think that this is impossible since regular concrete is 2.3 times denser than water. However, steel is even heavier than concrete and we still use steel to build large boats. The answer to this physical problem was given by Archimedes over 2000 years ago; his principle states “a body immersed in a fluid experiences a buoyancy force equal to the weight of the fluid it displaces”. Therefore, to build a concrete boat we only need to design a concrete container so that the buoyancy force balances the vertical force (including self weight).

Indeed, we can build boats made out of concrete. Civil Engineering students in the USA know this well as concrete canoe races between rival Universities is a very popular event. First concrete boats were built in the 19th century in Europe by J.L. Lambot (Southern France, 1848) and C. Gabellini (Italy, 1890s). An interesting historical application was the portable floating reinforced concrete (RC) harbours used during the WWII on the D-day in the “Operation Mulberries” which were used to transport troops and heavy vehicles from England to Normandy (see here for details about construction).

Figure: Examples of concrete boats, Left – concrete anoe racing; Right – RC floating harbour used in WWII

Nowadays reinforced concrete floating caissons are widely used in civil engineering to build harbours, bridge foundations and offshore structures which are often built in a dry deck and then floated into the sea and sank into its final position. Perhaps the most impressive application of floating concrete structure is the MPU heavy lifter developed in Norway in 2009  (see here). This structure, which was built using lightweight aggregate concrete, is able to float into the North Sea, lift up an oil rig platform and move it to a different location. To give you an idea of the size of this floating structure, the overall height is 55m which is equivalent to a 18 storey building.

]]> 0
Health Monitoring: Cars vs Bridges Mon, 18 Jul 2011 13:48:09 +0000 Muhammad Imran Rafiq

The average price for a new car in the UK is around £20,000 and according to the Daily Telegraph on 11 February 2011, there are over 31 million registered cars in the UK. Average annual maintenance of a car would cost around £300.00 and the average life of a car in the UK is probably around 1 years. Yet, a modern car has over 200 sensors to provide necessary data to optimize its performance and increase its service life.

In the comparison, Bridge infrastructure in the UK, which totals at around 150,000 and their capital cost runs in Trillions.  The design life of a bridge is expected to be 120 years and good few hundred million pounds are spent on their maintenance and repair every year. Yet, some parts of the bridge community have a strong view that it is not worthwhile to install sensors to monitor the bridges.

Any suggestions?

]]> 0