Concrete Laboratory Teaching Vid

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					                Teaching Development Fund 1999/2000
                            Case Study

                Concrete Laboratory Teaching Video
                    Project Leaders: Peter Walker and Tim Ibell
                 Department of Architecture and Civil Engineering
                  emails: abspw@bath.ac.uk and abstji@bath.ac.uk


Context
An essential element of any Civil Engineering degree is for students to see how
concrete structures actually behave through to failure. This provides students with a
‘feel’ for concrete structures and equips them for advanced engineering design
beyond the constraints of Codes-of-Practice.

This element of a Civil Engineering degree is normally taught in a laboratory and
typically consists of loading (to destruction) concrete structures of various form.

The Department of Architecture and Civil Engineering has a main Structures
Laboratory, where all research and taught testing is undertaken at present. This
laboratory is of insufficient size to allow any sizeable teaching experiments to be
conducted regularly. Therefore, up until this project, all teaching experiments on
concrete structures have been carried out on very small specimens (concrete cubes of
one litre volume and mini-beams of 500mm length). While important for general
concrete understanding, these experiments are in themselves insufficient to
demonstrate the full range of concrete behaviour to undergraduate students.

Initial Aims
It was felt imperative that our students watch the failure of reinforced concrete beams
(each failing in different manners) and concrete columns in their second year of study,
followed by prestressed concrete beams and concrete slabs (failing in different
manners) in their fourth year of study. Given the space constraints in the main
Structures Laboratory, it was felt that this would be best done by filming
professionally these tests being carried out during Summer 2000 and then showing
videos of these tests to future students in their second and fourth years. As part of a
structured tutorial, we would require the students to predict failure modes and
capacities prior to watching the videoed experiments, followed by submission of a
laboratory report. During the laboratory write-up, students would be able to access the
webpage for these experiments, which would contain video stills, tutorial sheets and
all experimental data necessary to complete the laboratory report. This webpage
would additionally serve as a repeatably-accessible resource for our students, of
tremendous educational benefit.

In this way, the laboratory constraints would be overcome, while simultaneously
providing excellence in concrete teaching. To our knowledge, this approach was
novel and a cost-effective compromise in order to educate our students properly. We
also felt this teaching method would help keep focus on the experiments, due to the
edited length of the video, rather than allow students’ attention to drift in a real
laboratory.
As evidence as to its viability, at the time of applying for this project funding, we
learned that the British Cement Association was currently considering producing such
a video, presumably for purchase by Higher-Education Institutions in the future. We
felt we required this video rather more urgently than this, and one that was tailored to
those facets of concrete engineering which we believe to be crucial.

Project Implementation
During the design of the experiments to be conducted and filmed, we decided to
extend the scope from 3 reinforced concrete beams, 1 column, 1 prestressed concrete
beam and 2 slabs to 4 reinforced concrete beams, 2 columns, 2 prestressed concrete
beams and 2 slabs. This was done to include another three distinct failure modes in
the virtual laboratory and also to show the behaviour of fibre-reinforced-plastic as
reinforcing material for concrete structures of the future.

The formwork for all specimens was constructed during July 2000 and casting of the
specimens began on 4 August 2000 and lasted a fortnight. Testing and filming of the
tests started on 6 September 2000 and lasted 3 days in total. One of the tests did not
fail in the manner in which we had hoped and this specimen was recast, tested and
filmed two weeks later. Apart from this particular specimen, all other aspects of the
laboratory work went according to plan.

A script for the video was written by the Investigators. Together with Mark Price of
Audio Visual Aids, University of Bath, who had filmed all the tests, editing of the
final video was carried out during the second week of February 2001, in time for 2 nd
and 4th year students on their respective concrete design courses to witness and
comment on the virtual laboratory system.

Also during February 2001, all data from the tests was converted to graphical output
and individual tutorial sheets (laboratory reports) for each test conducted were
created. The webpage for the virtual laboratory was written and mounted at
www.bath.ac.uk/~abstji/concrete_video/virtual_lab.htm. Versions of the tutorial
sheets in .pdf format were added to the site, as were video stills at various load
increments for each test.

Feedback
At this stage in February 2001, the final 22-minute video, accompanying webpage and
tutorial sheets were ready for evaluation by 2 nd and 4th year students, as well as
outside bodies. In particular, we approached The Concrete Society, a highly-respected
learned society in the U.K. for their comments on the virtual laboratory package. They
sent back very positive comments and they published an article in their 'Concrete'
Journal about Bath University's initiative. This attracted a response from the South
African Concrete Society, to whom we also sent the full package for comments. They
too were very supportive of the concept and now plan to carry out a similar project
themselves.

In terms of detailed feedback from our own students at Bath, the following
summarises the 'scores' out of 5 which were allocated in the most important three
categories from a total of 61 returns:

Importance of the video as a teaching resource               4.0
Quality of the tutorial sheets and webpage                   4.2
The concept of a video as a substitute for real testing      3.8
We feel that these average scores reinforce the success of the project. However, it
must be conceded that students obviously felt slightly ill-at-ease with the video
becoming a pure substitute for physical testing, judging by the marginally-lower score
in this category and by some comments received. The intention of the virtual
laboratory was never to entirely replace all physical testing on concrete structures, but
rather to expand the number and range of tests offered to students. This point will be
made clear to students this coming academic year. It has not been felt necessary to
alter anything about the overall package based on all feedback received.

Key Advice
We found that the help of an experienced cameraman and editor was vital to the
successful creation of a professional video. Without such help, the quality of the video
would have suffered. When we initially introduced the virtual package to our students,
we did not fully explain the background and circumstances surrounding the idea of
using such a system as a backup, not a substitute, for physical laboratory testing. This
will be rectified in future. Our advice would be to explain clearly to students the
advantages of any innovative teaching aid before thrusting it upon them.

				
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