Friday 6 April 2018

Final Report (SIT FC)



1. Introduction

According to Meteorological Service 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. Singapore has been facing flooding issues occasionally due to the increase in the average temperature and change in precipitation related to global warming. As a result, members of the community of Singapore Institute of Technology (SIT) faces similar “ponding” issues whereby storm water are left stagnant on the surface of the walkways for a period whenever there are heavy recurring rains.

The current walkway is made of conventional concrete which has an impermeable surface. Conventional concrete is unable to allow water to seep through and this will lead to “ponding” issues. Hence, there is a decrease in friction on the surface of these walkways when “ponding” occurs and in turn jeopardising the safety of the community. With these walkways being impermeable, it causes inconvenience for the SIT community as footwears and clothes gets drenched while walking along the walkways. With that, the walkways are unable to facilitate SIT’s population under these heavy downpour circumstances based on observations and personal experiences.

To overcome this issue, pervious walkway should be introduced to overcome “ponding”. Pervious walkways are made from concrete which consist of well graded aggregates. This allows water to seep through the voids as compared to conventional concrete which has little to no voids. Also, the voids from the concrete ensure that the surface of the pervious walkway is rougher as compared to conventional concrete and this in turn increases the friction of the walkway. With this, the permeable surface of pervious walkway allows storm water to drain through its surface and seep into the soil below therefore, reducing “ponding” and with the rougher surface, it improves the safety of the community by reducing chances of slip and fall.

2. Problem Statement

SIT community should be able to walk without difficulties on concrete walkways that are anti-slip and dry. To prevent slip and fall incidents from happening in SIT@Dover, having pervious walkways will mitigate ‘ponding’ whenever it rains. However, there are no pervious walkways in the campus and this results in various instances where slip and fall are prone to happen. SIT’s Division of Estate should therefore replace the impermeable walkway to a pervious walkway to prevent the problem at hand.

3. Purpose Statement

The aim of this report is to propose to SIT’s Division of Estates the implementation of pervious walkways along the walkway connecting the back gate and USC to reduce the inconvenience and to create a safer walking environment for the community.

4. Current Implementation

Both figure 1 and 2 shows the current implementation of the walkway. Figure 2 depicts the dry state of the area whereas figure 1 shows the “ponding” problem that is evident especially after it rains. This is because the current material used is conventional concrete and due to its impermeable surface, storm water is just left to dry, thus making it inconvenient for users to walk across.

Proposed Solution

The team has proposed a solution to replace the current implementation with pervious walkways. The walkway connecting the back gate and USC is chosen as it is prone to “ponding”, as seen in figure 1, especially during heavy recurring rains which happens frequently these days.

As the current concrete used along the walkways are conventional concrete, the replacement with a Neupave C30/37 well graded concrete which consist of compressive strength of 30MPa (Megapascal), will enable storm water to be drained into the collecting basins underneath the walkway. Apart from that, this concrete has a rougher surfacing due to its pores which in turn improves the overall safety for the community by increasing the friction on the surface.

To ensure that this proposed solution could be implemented in an effective manner, the chosen walkway will be used as a test bed for this project. This is so that SIT’s division of estates are assured that the area considered as a “prototype” is fully located in SIT@Dover’s campus.

5.1 Technical Information

Pervious walkways differ from conventional walkways as it allows water to infiltrate through the surface, thus preventing “ponding.” How this is achieved is by using pervious concrete instead of conventional concrete. A pervious concrete mixture contains little to no sand, creating a substantial void content. By using sufficient paste to coat and bind the aggregate particles together, it creates a system of highly permeable, interconnected voids that drains water quickly. According Typically, between 15 to 25% voids are achieved in the hardened concrete (Pervious Concrete Pavement, 2011) 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.
5.2 Benefits of Pervious Walkway

5.2.1 Reduces storm water runoff

Permeable pavements help re-establish a more natural hydrologic balance and reduce runoff volume by trapping and slowly releasing precipitation into the ground instead of allowing it to flow into storm drains and out to receiving drains as effluent. This same process also reduces the peak rates of discharge by preventing large, fast pulses of precipitation through the storm water system.


5.2.2 Improve discharge water quality

Permeable pavement can reduce the concentration of some pollutants either physically (by trapping it in the pavement or soil), chemically (bacteria and other microbes can break down and utilize some pollutants), or biologically (plants that grow in-between some types of pavers can trap and store pollutants).

5.2.3 Reduce overall project cost


The implementation of pervious concrete provides lower overall costs as no underground piping and storm drains 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.

5.2.4 Provide friction

Additionally, as pervious concrete has a rougher surfacing as compared to a conventional concrete due to pores on the surface, it will be able to provide the friction needed to avoid users from slipping especially during heavy rains and therefore, reducing the probability of a slip and fall incidents.

5.3 Limitations of Pervious Walkway

Though there are various benefits to using pervious concrete, there are certain restrictions that comes from this proposed idea.

Pervious walkways should be properly designed to accommodate the amount of storm water runoff that is expected in the area. If not adequately designed, the water table below the pavement can rise, preventing storm water 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.

The team interviewed fellow lecturer at SIT@Dover, Dr Feijin, who specialises in concrete materials and design. He mentioned that because pervious concrete has such a high void content, its overall strength is generally lower than that of regular concrete and 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 would not be an issue as no heavy loading is applied there.


Lastly, the team gathered relevant facts regarding the usage of pervious concrete from a professional engineer, Teo Yong Boon, in SamWoh Corporation Pte Ltd that specialises in ready-mix concrete. He explained that the main drawback of using pervious concrete is maintenance. As mentioned in the article “Permeable Pavement: The Pros and Cons You Need to Know,” The concrete is prone to clogging due to sand and fine particles. As a result, an industrial vacuum would be needed to unclog these particles. If this is not carried out appropriately, water would start to ‘pond’ on the surface, defeating the whole idea of reducing ‘ponding’ occurrence.


5. Potential Solutions

Besides incorporating pervious concrete, there are various other potential solutions that could be considered. Such examples include sloping the walkway, whereby a slope of certain gradient is constructed along the walkway for surface water to flow into the nearby drains. 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.

6.1 Limitations of Potential Solutions

The process of creating a gradient for a slope may affect the community as they are unable to travel along the pavement while it is being reconstructed. Also, current drains as shown in Figure 4 would probably need to be enlarge as gradient is introduced, the surface water runoff increase and when the drains could not handle the input, it would clog and floods the area.

Durability of stamped concrete is an issue as it has low durability compared to other surfaces and methods. This is a rather a more relevant 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.

6. Methods/Procedure

To ensure sufficient knowledge is gained before recommending the use of pervious concrete, research was done to ensure the team had an in depth understanding. The team narrowed down the research and 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 factors contributing to a “slip and fall” incident.

7.1 Primary Research

Survey and interviews were carried out by the team to get sufficient data to prove that this is an ongoing problem in SIT@Dover as seen in Appendix A.


7.2 Secondary Research

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;

The guideline also provided grading of the slip resistance of some of the typical materials used for floor finishes. Attached as Appendix C.

7. Conclusion

Though there are certain limitations that pervious concrete brings such as clogging of the pores. This limitation can be resolved by using an industrial vacuum. As compared to conventional concrete, pervious concrete does not require drains and piping to redirect storm water. Instead, pervious concrete enables storm water to seep through and be drained into the collecting basins underneath the walkway. This will in turn reduce the overall cost of the system.


As mentioned in the proposed solution found under section 5.0, the compressive strength of pervious concrete is 30 MPa. The strength makes it suitable for the chosen walkway as there is no high imposed dead load such as building acting on it.


To conclude, reconstructing the current walkway with pervious concrete instead is certainly the optimum solution to overcome slip and fall incidents in SIT. As safety is always the number one priority in all places, the community should never feel unsafe especially when walking along the school premises.


References



Awang, F. N. (2016, November 28). Paralysed man who sued town council after fall dies. The New Paper. Retrieved from http://www.tnp.sg/news/singapore/paralysed-man-who-sued-town-council-after-fall-dies

BA Contracts Pte Ltd. (2017). Permeable pavers at Hort Park. Retrieved from http://bac.com.sg/permeable-pavers-hort-park-singapore


Building and Construction Authority. (n.d). Quality standards. Retrieved from https://www.bca.gov.sg/qm/quality.html


Concrete Network. (n.d). Economic Benefits. Retrieved from https://www.concretenetwork.com/pervious/economic_benefits.html


FindLaw. (n.d). Slip and fall accidents overview. Retrieved from http://injury.findlaw.com/torts-and-personal-injuries/slip-and-fall-accidents-overview.html


GreenBlue Urban. (n.d). Permeable pavement: The pros and cons you need to know. Retrieved from https://www.greenblue.com/na/permeable-pavement-the-pros-and-cons-you-need-to-know/


Meteorological Service Singapore. (n.d). Climate of Singapore. Retrieved from http://www.weather.gov.sg/climate-climate-of-singapore/


Neupave. (n.d). Permeable pavers [Brochure]. Retrieved from http://bac.com.sg/wp-content/uploads/2016/05/Neupave.pdf

Analytical Reflection


For the showcase, teams used various audio and visual to help attract audience attentions in the presentation. A good example is team S.U.N which played a short video to gave audience a quick overview and the effectiveness of their product.



In my view, team ASTAR did a very good presentation overall. I was able to easily read and understand the presentation slides as they had designed it very well with eye-catching colours when delivering their content. Their message is clear and managed to get it through the audiences with their well added pictures to support themselves. Understanding them was not hard as they kept their tone and pace loud and consistent throughout the presentation and never fails to maintain eye contact with all the audience. Overall, team ASTAR delivery was fluent with few filler words. Their content about food waste was something that speaks to me as I myself have wasted food countless of times and I know it is the same for many. It shows how much waste one person could stack up in food alone which is creating a major problem in the time to come in Singapore. It was clear to me that the starting tone of the first presenter wanted us to know the seriousness of the problem at hand which blends in well with their topic.



To sum it all up in my opinion, confidence, composure and knowledge of your own product is important to achieve a good presentation. With the aid of clear, neat and simple slides combined with clear visible picture to give help audience to follow and understand the presenter throughout. I have learned many things in the show case and hope to present like team ASTAR in the future.

Final Readers Responds


In the article, "Porous Asphalt Is King of the Road" on the website Pave Green (n.d), porous asphalt has proven its benefits by improving the environment, safety and minimizing cost. Porous asphalt has since been recognized by the Environmental Protection Agency and is being used on pavements throughout United States.

Small aggregates are excluded from the porous asphalt mixture to allow water to pass through, acting like a filtration system. This significantly reduces flooding and erosion on roads and parking lots. Superhighways use the same mixture as it helps to drain water, improve water quality, remove splashes and significantly reduce accident rates.

The article also mentioned that porous pavements are beneficial in wintery climates as it allows snow to liquefy at a faster rate, reducing cost of anti-icing agents, making it cost-effective and eco-friendly. Despite the high cost of porous asphalt, the overall cost of construction balances out from the savings made from purchasing water pipes and inlets. While porous asphalt roads provide beneficial properties, there are several disadvantages and potential challenges faced that the author did not discuss on.



Firstly, the article mentioned that porous asphalt is effective in tackling flooding situations as the mixture allows water to drain. However, this may only be feasible in countries with urban infrastructure and evenly spread population such as the United States or Australia.

In the article "Paving Paradise: The Peril of Impervious Surfaces", Frazer (2005) mentions that countries like the United States have wider roads, larger parking lots and houses with accompanying roofs are contributing factors which offers additional protection for impervious surfaces unlike India where the populace live in scattered village without paved roads. This suggests that effects of porous asphalt are efficient in improving the water absorption on impervious surface however there are many contributing factors which assist in reducing floods and erosion.



In addition, the Pave Green article states that safety plays an important role in making porous asphalt "King", is helpful in reducing the amount of water on the surface of superhighway providing better visibility on roads reducing accident rates. However, in the article "Accident Analysis & Prevention" by Elvik (2016)* states that there is an insufficient change of accident occurrence between (on roads with) porous asphalt and conventional in accident rates, evaluated by nine different risk factors. While porous roads provide increased safety properties, the article suggest that there is no visible change in accident rates between the usage of porous and conventional asphalt.



The author mentions porous asphalt was cost efficient through reducing the usage of anti-icing agents and construction of drainage. The overall construction cost will offset the extra cost incurred on the stone bed, which is thicker than conventional asphalt. Loosdrecht (2012) stated in the book Water Research that over time, the filtration bed underneath will get clogged causing a layer or "cake" which prevents water to pass. Maintenance by "vacuuming and sonication" could be used to unclog the beds, but not totally. Hence, water clogging would still be a problem in the long run. It is evident that even with regular maintenance to prevent clogging of the roads. This led us to wonder if the cost of maintenance of the porous asphalt would be less than using conventional asphalt.



In conclusion, the article has effectively mentioned the successful application of porous asphalt in the United States. The porous asphalt is environmentally friendly, cost-efficient, and it increases safety on roads. However, I believe that there is no perfect solution to any issues and we cannot only look at the advantages and fail to evaluate the possible disadvantages.







Porous Asphalt Is King of the Road. (n.d.).
Retrieved February 18, 2018, from http://www.pavegreen.org/index.php?option=com_content&view=article&id=58%3Aking-of-the-road&catid=35%3Aporous-asphalt&Itemid=110

Elvik, R. (2005). Road safety effects of porous asphalt: a systematic review of evaluation studies. Accident Analysis & Prevention.
Retrieved February 18, 2018, from https://www.sciencedirect.com/science/article/abs/pii/S0001457505000175.

Lance Frazer (2005). Paving Paradise: The Peril of Impervious Surfaces
Retrieved February 01, 2018, from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1257665/

Loosdrecht M. V. (2012). Water Research.
Retrieved February 01, 2018, from https://www.sciencedirect.com/science/article/pii/S0043135411006166





Frazer, L. (2005, July). Paving paradise: The peril of impervious surfaces. Environmental Health Pespectives, 113(7). Retrieved from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1257665/.



Critical Reflection

At the beginning of Effective Communication course, I approached this module with optimism to learn more about the tips of communicating effectively. I had given myself two goals for this module which are improving my presenting and writing skills to build up my confidences. During the 12 weeks in this course, I had not only improved my presenting skills from many mock presentations during class, but also in my writing skills from assignments such as readers responds and technical report. There are other key takeaways such as public speaking, body posture and articling words clearly too. Effective communication enables me to deliver my thoughts and feelings as clearly and effectively as possible which I know will be useful for the years to come. I will try to read more to improve my skills as there’s a saying which is learning never stops.

If I was asked to discuss one takeaway from my technical proposal project, it would be teamwork. Teamwork not only teaches me to compromise when all group members have different views but also listening, as being a leader does not mean you are always right. Organizing the team to be on track and time management do not show how well a leader is good at leading but tells how good the team is united to finish the task at hand. I am also very thankful for my team, SIT FC, for helping me by placing themselves in my role when I am not available to be there. It is a hard period for me, but they are all fully willing to lend a hand on top of all their busy assignments.

To conclude, this module was a fruitful and productive one and given me the motivation and confidence. From here and out, I will further improve my communication skills as I said earlier, learning never stops.



Commented on: Roland , Glen and Serena

Thursday 15 March 2018

Letter Of Transmittal, Draft1

March 15, 2018


From: Colin Tan


To: SIT Division of Estate


Cc: Brad Blackstone


Subject: Proposal for Implementing Pervious Concrete Along Sheltered Walkways in SIT@Dover


Dear Sir/Mdm,


I am Colin Tan, on behalf of SIT FC, a year one student from Civil Engineering programme at Singapore Institute of Technology (SIT). I was assigned to a project group with three other students by our lecturer Mr Brad Blackstone to identify, study and solve a civil engineering problem in Singapore. With that in mind, the team has decided to investigate the issue of slip and falls in the SIT@Dover campus due to the slippery and prone to “ponding” walkways and find a reasonable solution to this problem to ensure the safety of the campus population.


Attached is our proposal to achieve the aforementioned goal. This report contains the current implementation of the situation and its probable causes, our investigation of the situation through surveys and also our proposed solution to solve the situation with technical details and comparisons.


Do let us know should you require additional information with regards to the proposal and we will gladly provide the information. Thank you for your consideration and we hope to hear from you soon.


Best regards,


Colin Tan


Civil Engineering


Singapore Institute of Technology

Executive Summary, Draft 1

Due to its geographical location and maritime exposure, Singapore’s climate is distinguished by uniform temperature and pressure, high humidity and plentiful rainfall. As such, monsoon season in Singapore may result in flooding due to the obsolete stormwater management.


The aim of this report is to propose to Singapore Institute of Technology’s (SIT) division of estates the implementation of pervious concrete along a walkway connecting the back gate and USC. Therefore, the chances of a slip and fall incident can be greatly abbreviated.


In this report, the benefits and limitations of implementing the solution are further addressed, along with alternative solutions and potential issues. Also, various research was carried out to obtain information to justify the proposed solution. Primary methods include conducting a survey on campus and consulting professors who are skilled in the relevant field of study. Secondary research methods include obtaining statistics on cases of a slip and fall incident on campus, and standard measurements of floor surfaces in Singapore set by Building Construction Authority (BCA): Code of Accessibility.

Personal Statement,Draft 1



Colin has four years of civil engineering experience with special interest in earth work. He interned in Land Transport Authority (LTA) for three months overlooking earthworks for the Mandai depot. With his extensive experience in earthworks, he fully comprehends the needs for constructing a walkway and its obstacles to ensure safety.

Final Report (SIT FC)

1. Introduction According to Meteorological Service Singapore, Singapore is situated near the equator and has a typically tropical clima...