Background
According to the article
“Climate of Singapore,” Singapore is situated near the equator and has a
typically tropical climate, with abundant rainfall, high and uniform
temperatures, and high humidity all year round. Through the recent years,
Singapore has been facing flooding issues occasionally due to the increase in
the average temperature of the Earth’s atmosphere and the outdated stormwater
management system. As a result, Singapore Institute of Technology (SIT) faces
similar flooding issues whenever there are heavy recurring rains. Currently,
there is a lack of implementation of anti-slip pathways to facilitate SIT’s
population under these heavy downpour circumstances based on observations and
personal experiences. This results in many instances whereby slip and fall are
prone to happen. Also, with the pavements being impermeable, flooding and
“ponding” are bound to occur when it rains and this causes inconveniences for
SIT’s population as footwears and clothes get drenched.
When a Slip and fall
incident occur on a property (or "premises") owned or maintained by
someone else, the property owner may be held legally responsible (“Slip and
Fall Accidents Overview,” n.d.). There were actual cases whereby a slip and
fall incident has resulted to the victim filing a lawsuit against the property
owner. According to an article from The New Paper, a man slipped and fell at a
sheltered walkway and as a result, suing the town council after he became
paralysed due to the fall. Ultimately, as a technical educational institute, a
slip and fall incident is certainly an issue that SIT would want to prevent.
Being the fifth autonomous university in Singapore, there
are numerous reputable stakeholders that visits SIT for seminars/talks. When
these stakeholders visit the school, they will walk along the aforementioned
sheltered walkway and when it rains and starts “ponding”, it will leave a
negative first impression about the school. This is mainly because the walkway
is outdated as these “ponding” occurs due to the usage of impermeable concrete,
and the poor drainage system. As a result, SIT’s reputation may be affected as
these types of safety precautions should never be overlooked.
Problem
statement
In order to prevent slip
and fall incident from happening in SIT@Dover, installing anti-slip pathways
will mitigate ‘ponding’ or flooding whenever it rains. However, there is a lack
of implementation of anti-slip pathways to facilitate SIT’s population under
heavy downpour circumstances. This results in various instances where slip and
fall are prone to happen. Implementing the use of pervious and anti-slip
pathways will therefore reduce inconvenience to users as it mitigates ponding
when it rains heavily in SIT.
Purpose
statement
The aim of this report is
to propose to SIT’s division of estates the implementation of pervious pathways
along 3 flood prone areas around the campus in order to create a safer
environment for the community. The 3 areas that will be focused on are, front
and back gate sheltered walkway, and the walkway that leads towards the
University Services Centre from the back-gate entrance.
Proposed
Solution
The team has proposed a
solution whereby pervious anti-slip pathways are to be implemented along the
previously mentioned areas. These areas were chosen as they are prone to
“ponding” especially during heavy recurring rains which happens frequently
these days.
Pervious concrete pavement
is a unique and effective means to address important environmental issues and
support green, sustainable growth. By capturing stormwater and allowing it to
seep into the ground, pervious concrete is instrumental in recharging
groundwater. Pervious or permeable pathways differs from traditional pathway as
it allows water to infiltrate through the surface, thus preventing “ponding.” How
this is achieved is by using pervious concrete instead of ordinary concrete. A
pervious concrete mixture contains little or no sand, creating a substantial
void content. Using sufficient paste to coat and bind the aggregate particles
together creates a system of highly permeable, interconnected voids that drains
quickly. Typically, between 15% and 25% voids are achieved in the hardened
concrete (Pervious Concrete Pavement, 2011). When concrete is manufactured, the
amount of water used in the mix is crucial. Water to cement (w/c) ratio is used
to determine the amount of water and cement accordingly. Ordinary concrete
typically has a w/c of 0.6 to 0.7 whereas pervious concrete has a ratio of 0.28
to 0.4. The lower the w/c means the mix is more ‘dry’ therefore creating more
voids for water to seep through.
As the current material
used along the walkways are regular cement, the replacement of porous anti-slip
pathway will now enable storm water to be absorbed into the collecting basins
underneath. By reducing ponding on the surface and having anti-slip tiles, it
creates a much safer walking area as more friction are present. This can
therefore decrease the likelihood of a slip and fall incident from occurring.
In order to ensure that
this proposed solution can be implemented in an effective manner, the walkway
connecting University Service Centre (USC) to the back gate will be taken as
the “controlled” factor such that it will be the proposed location for this
project. This is so that SIT’s division of estates are assured that the area
that is first considered as a “prototype”, is fully located in SIT@Dover’s
campus. Concerning the fact that this project may cause obstructions to
students as it may be inconvenient to travel from one location to another, this
project is to be reconstructed over the trimester break, whereby there will not
be as many students and faculties around, so as to minimise the amount of
inconvenience caused.
Potential
Solutions
Besides incorporating
pervious concrete in order to overcome the ponding issue, there are various
other potential solutions that can be considered. Such examples includes the
gradient of the the slope, whereby a pathway is generated for water to flow
into the nearby drains. Alternatively, the method of stamping on existing
concrete in order to create friction, may also be an idea that can be studied
to further improve the use of pervious concrete.
The slope of the pavement
plays a major role in the current issue of flooding. Based on the article,
“Flooded Basement? How to Deal with Common Causes,” it stated that one of the
causes of flooding is due to pavement slope. The article also mentioned that
the pavement would settle overtime and that would affect the gradient and
direction of the pathway. If that happens, the solution is to remove and
replace the pavement so that it will slope to another direction. Creating a
slope in the opposite direction helps with the flooding as a pathway has been
generated for the stormwater runoff to be directed towards an area such as a patch
of grass, or an open space that is not prone to flooding. By doing so, the
pavement would be kept dry and people would not have a hard time trying to walk
as slowly as possible to avoid splashing of muddy or dirty runoff on their
shoes or pants. The cost of changing the slope of the pavement is relatively
cheap as it can be hack away and then recast concrete on it. However, the
process of changing the slope would affect the community as they are unable to
travel along the pavement when it is being reconstructed.
Stamped concrete is another
alternative that could be implemented. It is basically a patterned and/or
textured concrete to look like a brick, wood or any texture desired. This
method is cheap and has the least maintenance compared to the rest. Apart from
that, ease of installation is also an advantage for this method. It is also
longer lasting than most of the other alternatives. However, durability is an
issue as it has low durability compared to other surfaces and methods. This is
a good method for creating customize looks for patio, pool side tiles or even
backyard as it focuses more on aesthetic rather than solving the issue at hand.
Another simple alternative
would be to introduce a drainage system along the pathways mentioned.Currently,
there are no visible drains along these troubled pathways which could be the
main contributing factor to these ‘ponding’ issues.
Benefits
The team’s main priority
for proposing this project is the safety of the SIT community. There are
various advantages when it comes to using pervious concrete. Firstly, such
advantages includes the environmental benefits. When it comes to providing
benefits to the environment, pervious concrete are able to eliminate runoff,
recharge groundwater, and even eliminate the need for retention basins and
water collection areas. Not only that, suspended solids and pollutants will be
trapped within the pervious concrete, therefore reducing the chances of
“ponding.”
Secondly, another advantage
when it comes to using pervious concrete, is the financial benefits. The
implementation of pervious concrete eliminates the costs for retention basins,
curbs, gutters, and other water collection installations. It also provides
lower installation costs as no underground piping, storm drains, or sloping/grading
are needed. The low life-cycle costs of pervious concrete can be compared with
regular concrete such that it has an equal life expectancy to that of regular
concrete: 20 to 40 years when correctly installed.
Lastly, the anti slip tiles
would provide the necessary friction needed to prevent users from slipping
especially during heavy rains and thus reducing the inconvenience experienced
amongst the users now.
With all these benefits in
mind, SIT’s division of estates can certainly reap the benefits. Instead of
utilizing the ordinary concrete when developing a walkway, executing the use of
pervious concrete in a college campus will certainly have a positive impact on
the school's image. Besides that, external stakeholders such as Land Transport Authority
(LTA) may also incorporate this idea along the sheltered walkway from the back
gate bus stop to the entrance of the campus. Especially, considering the fact
that flooding always occur at that area whenever there is heavy rain. By
incorporating the use of pervious pathway, this recurring issue will definitely
be solved.
Evaluation
Though there are various
benefits to using pervious concrete, there are certain restrictions and doubts
that comes from this proposed idea.
A pervious pavement project
should be properly designed to accommodate the amount of stormwater runoff that
is expected in the area. If not adequately designed, the water table below the
pavement can rise, preventing stormwater from being absorbed into the ground.
Certain types of pervious pavements require frequent maintenance due to the
possibility that solids and particles may get trapped and clog pavement pores.
If the proper “vacuuming” or flushing is not carried out, pervious concrete
will assume the traits of impervious concrete. While it is estimated that
porous concrete can be two to three times more expensive than regular asphalt
or concrete, cost savings are simultaneously achieved as stormwater
installations are not necessary.
Besides that, the team also
went ahead to interview a fellow lecturer atSIT@Dover, Dr Feijin, who
specialises in concrete materials and design. He mentioned that because
pervious concrete has such a high void content and its overall strength is
generally lower than that of regular concrete, it is not recommended on heavy
loading areas. In view that this project is to be implemented along the
sheltered walkway leading towards USC from the back gate, utilizing pervious
concrete at this area seems to be the best choice as this part of the school is
not a place where heavy loadings are applied.
Apart from interviewing Dr
Feijin, the team has also gathered relevant facts regarding the usage of
pervious concrete from a professional engineer over at an engineering company
called SamWoh Corporation Pte Ltd which is one of the leading companies that specialises
in ready-mix concrete. They explained that although pervious concrete has its
advantages, one of the main drawback of using it widely is the maintenance. As
mentioned in the article “Permeable Pavement: The Pros and Cons You Need to
Know,” The concrete is prone to clogging if the water in the reservoir is not
drained out properly. As a result, an industrial vacuum would be needed to
unclog the sand and fine particles that clogs the voids. If this was not done
properly, water would starts to ‘pond’ on the surface, defeating the whole idea
of reducing ‘ponding’ occurrence.
Replacing the current
concrete to the pervious ones would definitely not be a simple process. It
would require the pathway to be blocked off for construction works to be done.
A temporary pathway wont then need to be constructed to allow pedestrian to
move along the back gate and USC while construction is done along the pathway.
Methods/Procedure
In order to ensure
sufficient knowledge is gained before implementing the use of pervious
concrete, various research were done initially to ensure the team has an in
depth understanding when it comes to the laws here in Singapore. To narrow down
the research, the team decided to search on the
guidelines provided by Building Construction Authority (BCA) regarding floor surfaces, standard measurements in Singapore when it comes to how
smooth or rough the floor can be, and statistics on the
number of people that experienced a “slip and fall” incident.
According to the guidelines
provided by (BCA), it is stated on the code of accessibility, “In The Built
Environment 2007,” floor surfaces shall –
(a) be stable, firm, level and slip-resistant;
(b) not have any projection, drop or unexpected variation in level;
(c) have colour and tone that are contrasting with the walls, otherwise the skirting must provide a clear distinction between the floor and wall; and
(d) Where there is a change in level, contrasting colour bands are to be provided to alert the users of the change in level.
(a) be stable, firm, level and slip-resistant;
(b) not have any projection, drop or unexpected variation in level;
(c) have colour and tone that are contrasting with the walls, otherwise the skirting must provide a clear distinction between the floor and wall; and
(d) Where there is a change in level, contrasting colour bands are to be provided to alert the users of the change in level.
The guideline also provided
grading of the slip resistance of some of the typical materials used for floor
finishes. Attached as Appendix B.
According to the quality standard of floors provided by BCA (BCA: Quality standards , 2009), the standard measurements in
Singapore when it comes to how smooth or rough the floor can be, are as
follows:
- Finishing
·
No stain marks
·
·
Consistent colour tone
·
- Alignments & Evenness
·
Evenness of surface (not more than 3mm per 1.2m)
·
·
No ponding in falls for wet area
·
·
Falls in wet areas should be in right direction
·
- Crack and Damages
·
No visible damage/effect
·
- Hollowness/Delamination
·
No hollow sound when tapped with hard object (for
Ceramic, Marble & Granite only)
·
·
No sign of delamination
·
- Jointing
·
Consistent skirting thickness and no visible gap
between wall and skirting
·
According
to the website from WSH Council, it is stated that slips, trips and falls (STF)
are the most common causes of injuries in workplaces. STF injuries contributed
to more than 20% of all workplace injuries and hurt more than 1,000 employees
every year. Besides sprains and strains, STF can also cause more serious
injuries like fractures and head injuries.
Slip, Trip
and Fall Hazards
Examples
of factors that may increase STF risks include:
- Insufficient lighting;
- Poor housekeeping;
- Wet and slippery floor and surfaces;
- Lack of handrails on platforms or staircases;
- Unsafe use of ladders;
- Uneven walking surfaces
Apart from conducting
research on the guidelines from BCA, a survey was conducted around SIT@Dover
campus to find out what the students and faculties experience when they walk
along the mentioned sheltered walkways whenever it rains. Each of the project
members were given a task to survey 3 people each so as to get sufficient data
to prove that this is a ongoing problem in SIT@Dover. In order to ensure that
the survey is not biased, members of the community were also considered as part
of the subject for the survey besides students. The questions asked and the
results collected are as follows:
Question 1: Have you ever
slipped/fell along the pathway connecting USC and the back gate?
Results: Out of 12 people
we surveyed in total, 9 of them said yes.
Question 2: On a scale of
one to ten, how safe do you feel walking along that pathway when it rains
heavily? (1 = Safe, 10 = Unsafe)
Results: The average number
we gathered from the same 12 people is about 7.
Question 3: On a scale 1 to
10, How convenient is it to walk along that pathway when it rains heavily? Etc
getting drenched, slipping. (1 = Very convenient, 10 = Inconvenient)
Results: The average number
gathered is about 8.
Based on the results
gathered, it can be concluded that most of the SIT@Dover population agrees with
this hypothesis. Given that, reputable sources were interviewed to ensure the
proposed solution is doable and feasible.
As such, the team
interviewed a fellow lecturer, Dr Feijin, who has a phd on concrete materials
to provide insights of pervious concrete. The main question directed to him was
regarding the fact that if pervious concrete costs cheaper than regular
concrete. He responded by stating that pervious concrete has been in placed in
many parts of the world now. It is a tested method to reduce “ponding” issues.
However, it has lower strength compared to regular concrete due to its increase
in void spaces that allows water to seep through it. Nonetheless, it has more
than enough strength to withstand the load.
Apart from that, we also
manage to interview the manager of SamWoh while on our learning journey. He
gave similar insights about pervious concrete as Dr Feijin did with an
additional comment stating that the maintenance is the main drawback for
pervious pathways to be used regularly.
Concluding
Statement
In conclusion, the main
takeaway from this proposal is the safety of the SIT@Dover population.
Replacing the current traditional concrete to pervious concrete should be
implemented in order to achieve the safety desired. Every method and/or
solution has its disadvantages and that goes the same for pervious concrete as
maintenance is the main drawback for pervious concrete to not be implemented
widely. Apart from that, comparing to regular concrete, pervious concrete cost
higher due to its specific w/c ratio to achieve the porosity. However, change
has always been expensive but change has to be looked at as a long term
investment as evident from changing normal lights to light emitting diodes
(LED). According to the article “Out with fluorescent garage lights, in with LEDs,” A “normal” 48″ fluorescent tube light is around $6 or
$7 per light. While the LED bulbs are more expensive by a mere $3 difference,
it isn’t much at all given the lower energy usage and long life. Change does
not happen overnight and most people resist to change due to precontemplation.
The constant denying of the problem at hand is the main reason change has been
neglected for the most part.
On the other hand, some of
the benefits porous concrete brings includes environmental benefits. It mimics
the drainage and filtration of natural soils hence the storm water collected at
its basins are cleaner than those usually collected by using rains. Another important
factor it brings is financial benefits for developers. It eliminates the need
for the costly stormwater detention vaults and piping systems as the pathway
itself is a detention area and also the cost of curb and gutter installation.
In summary, using pervious concrete would definitely have more benefits in the
future economically and environmentally.
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