Monday, 9 April 2018

Technical Report Final

1.0 Introduction

1.1 Background

This proposal is developed in response to the call for engineering problem solution. for creating solutions towards reducing the amount of waste specifically plastic to landfill in Singapore.

As Singapore’s human population has been increasing at a staggering rate of 4.028 million in the year 2000 to 5.612 million in the year 2017, the amount of waste produced has been increasing at an alarming rate. In the year 2016, 7.81 million tonnes of waste were produced compared to 7.67 million tonnes in 2015. Our only remaining landfill Semakau landfill is expected to be fully filled by the year 2035. With the pressure of our landfill filling up, NEA has been encouraging the local construction industry to incorporate more recycled and waste materials as building materials. (Eco-business, 2011)

The construction industry in Singapore has been using waste materials such as Recycled Concrete Aggregates (RCA), Washed Copper Slag (WCS) and Ground-granulated blast-furnace slag (GGBS) as the partial substitution for coarse aggregates (stones), fine aggregates (sand) and cement respectively. When part of the conventional materials is replaced with recycled or waste materials, it is termed as Green Concrete. Plastic waste can be converted into carbon nanotubes and it can be used as an additive in concrete. (Goy,2016) The project team sees the potential of using plastic waste as a material substitution in concrete and is going to focus on pitching the idea of incorporating plastic waste into concrete to BCA.


1.2 Problem Statement

To achieve sustainable construction in Singapore, local construction industry should be incorporating 30-40% of plastic waste into concrete as it is environmentally friendly and provides a new purpose for plastic waste. However, this approach has not been fully investigated in Singapore. By adopting this method in the concrete design in Singapore, Building and Construction Authority can reduce the amount of waste being released into the environment. Incorporating plastic waste into concrete would be environmentally friendly, cost-effective, reduce the weight of concrete and enhances concrete properties. This would be beneficial to the construction companies and the building users.

1.3 Purpose Statement

The purpose of this report is to propose to the management of Building and Construction Industry to adopt the idea of partially incorporating plastic waste as aggregates replacement in concrete, and to highlight the advantages of plastic as aggregates in concrete and the applications of it in building constructions.  


2.0 Proposed solution

Green concrete refers to concrete that has a partial or complete replacement of either cement, fine (sand) or coarse aggregates (granite stones) with waste or residual products. When the substitution materials are less dense than the conventional materials, lightweight concrete is produced.

The team’s proposed solution is to incorporate plastic waste as partial substitution of stones and sand in forms of moulded and shredded plastic while carbon nanotubes can be implemented as an additive of cement. Carbon nanotubes are used as a cement composite to reinforce the concrete making the concrete much more stable. Carbon nanotubes (CNTs) can be used concurrently with the shredded plastics as a supplementary material to improve certain properties of the concrete. CNTs are composed of tiny carbon atoms linked in hexagonal shapes that formed a cylinder nanostructure and they are being used as a cement composite to reinforce the concrete, making the concrete much stronger.
There are two common types of CNTs, they are the single-walled carbon nanotubes (SWCNTs) and multi-walled carbon nanotubes (MWCNTs). MWCNTs are commonly used as they are cheaper to make and have a better reinforcement in concrete.
With our proposed design of concrete mix, the concrete can be used as concrete in non-structural design.

2.1 Case Studies

In a research done in the United Kingdom, University of Bath has collaborated with Indian researchers in a two-year project using plastic waste as a partial replacement for fine aggregates in concrete. Their main purpose of the research is to determine how the properties of concrete will be affected when 10% of fine aggregates is replaced with waste plastic. It was concluded that the results were often lower than conventional concrete and further investigations are required to consider the use in the application of structural concrete.

In addition, a case study in Bangladesh has proved that by using carbon nanotubes, it helps to strengthen the concrete making the concrete more durable. A technological company called BlueRen believes that more plastic waste can be recycled and the use of cement to make concrete reduced, as carbon can be used as an additive in concrete instead.


2.2 Benefits

2.2.1 Improving Concrete Properties

Plastic waste has been increasingly used as a partial substitute for aggregates due to the versatility of plastics that can be customised to meet specific technical requirements. Plastics are non-biodegradable, extremely durable and have great resistance against chemical, water, and impact. (Jaivignesh and Sofi, 2017) These factors improve the properties of concrete and to some extent, acts as a solution to the disposal of plastic.

Plastic aggregates have been identified to improve properties such as abrasion resistance, impact resistance, ductility, shock absorption, and thermal conductivity. (Jaivignesh and Sofi, 2017) Ductility is one of the main properties that are very important for the safety of the building. Ductility helps the concrete to stretch well. High ductility is useful in harsh conditions as it will expand and contract well, as well as having freeze-thaw resistance. (Kumar and Kumar, 2016)

Application of carbon nanotubes has high thermal conductivity preventing cracks in concrete (refer to Appendix B Figure 11) and have tensile strength 100 times stronger than steel. (Goy, 2016) Concrete has very low tensile strength, by adding carbon nanotubes, it enhances concrete to be stronger, more stable and durable in a long term.  This is due to interlocking carbon-to-carbon covalent bonds.  (Refer to Appendix B Figure 7 & Table 10 for the comparison between carbon nanotubes and other cement composites).

2.2.2 Reduction of concrete weight

The usage of plastic waste as aggregates can also greatly reduce the weight of the concrete, producing lightweight concrete. (Kumar and Kumar, 2016) Lightweight concrete is very useful in urban areas as it can be installed on the top floors of high rise buildings. This is extremely applicable to structural buildings as it can be used in the construction of top floors in high rise buildings as the lightweight property eases the transportation to the top floors. The application of lightweight concrete in high rise buildings can reduce building cost, this will be further explained in 2.2.4.  (Jin, Jay, Yoon & Dong, 2015)

Utilizing lightweight concrete will be the future of Singapore construction industry as it will allow companies to build more iconic structures in Singapore, such as the Marina Bay Sands.


2.2.3 Environmental Sustainability

The utilization of plastic waste is environmentally sustainable as the plastic waste is being reused, hence, extending the lifespan of the plastic. Apart from this, utilizing plastic waste can help to reduce the dependence of importing construction raw materials from neighbouring countries. In addition, this can reduce the amount of plastic waste being released into the environment and landfill.

2.2.4 Cost Effectiveness

Using plastic waste is an effective way to save cost as plastics are relatively cheaper than aggregates. It is possible to utilize the vast amount of existing plastic waste accumulated in Singapore to replace a significant amount of aggregates in concrete production. This can help companies to reduce the overall cost of the construction project as they would not need to rely on our neighbouring countries such as Indonesia, to import raw materials and aggregates for construction purposes. Incorporating plastic waste into concrete can save a significant amount of cost as compared to traditional concrete production.


2.3 Evaluation

There are a few challenges when it comes to incorporating plastic waste into concrete (refer to Appendix A).

2.3.1 Low Strength

The addition of plastic waste does not bond well with cement paste. Hence, it causes the compressive, tensile and flexural strength of the concrete to reduce. The addition of steel fibres can help to restore some of the strength in concrete. (Jaivignesh and Sofi, 2017) Even with the addition of steel fibres, the concrete might not be strong enough to be used as a foundation concrete or load-bearing beam. This can be overcome by placing the concrete on the higher floor of the building. Alternatively, they can be used for aesthetic purposes on the interior and exterior of the building.

2.3.2 Operational cost

Plastic waste must be cleaned condition before being added to the concrete mixture as aggregates. Therefore, it is a hassle and an additional cost to ensure that plastics are unsullied. The overall cost would also increase when equipment might be required to monitor the gas emission and the presence of toxic and polluting elements. However, this only applies when heating is required to mould the plastic.

Companies deter from the use of carbon nanotubes due to the processing cost (refer to Appendix 2 Figure 8). The cost of carbon nanotubes is much steeper than other materials such as steel and carbon fibres. However, the cost of carbon nanotubes has decreased vastly in the year 2016 compared to the year 2001.

2.3.3 Size of Carbon Nanotubes

Incorporating carbon nanotubes in concrete can be a challenge due to the size of carbon nanotubes, refer to Appendix B Figure 9 to see the size of carbon nanotubes. It requires new technology like Dynamic Light Scattering (DLS) in order to process carbon nanotube.  DLS is a technology that has the ability to readily characterize a statistically significant number of particles. Although, it can even measure the size of carbon nanotube and the results but DLS do not clearly correspond to a single dimension (length or diameter) of the tube, rather to a combined value. Therefore, it is a challenge to incorporate carbon nanotube in concrete due to its estimation and not the exact value.


3.0 Methodology

This project team performed primary and secondary research that includes a site visit and obtaining online material from various sources and government organizations.

3.1 Primary Research

The project team had the opportunity to visit Samwoh Research and Development Centre as one of our module site visit. The project team talked to the lab manager, Mr. Teo Yong Boon regarding incorporation of plastic into concrete and there is researches on lightweight aggregates and adding of carbon fibres into concrete (refer to Appendix C). However, there was no information regarding the recycling of plastic waste for concrete.

3.2 Secondary Research

A range of secondary data was obtained from official websites, news articles and research journals. This project team gathered statistics regarding Singapore’s waste generation and recycling rate from National Environment Agency (NEA)’s website. A news article has been published quoting NEA promoting Singapore’s construction industries to incorporate more recycled and waste materials as building materials were used as a motivation to promote our idea to Samwoh Corporation.

4.0 Conclusion

With the National Environment Agency urging local construction industry to use more of recycled and waste materials. Our team’s proposal of incorporating plastic aggregates and carbon nanotubes in concrete provides various benefits. Even though there will challenges to be resolved, in the long run, the benefits will outweigh the challenges.
In conclusion, we hope that BCA will take into consideration of our proposal and promote the implementation of plastic waste into concrete to Singapore’s construction industry.
F

Executive Summary Final

This report was written in response to the call for engineering problem-solution proposal. In this proposal, the team presents a method to incorporate plastic waste into concrete. Building and Construction Authority has been urging the stakeholders in the construction industry to use waste as a construction material, providing a sustainable construction in the construction industry in Singapore. Therefore, the team is proposing to incorporate 30 – 40% of plastic waste into concrete.
This proposal will detail the effectiveness of incorporating plastic waste into concrete. The team suggests to partially replacing aggregates with shredded plastic waste and discusses its benefits and limitations. Carbon nanotubes can be added in as a supplementary material to meet any specific design requirements.
An evaluation of the benefits and possible limitations to these proposed solutions has also been included in this report.

Personal Statement Final

Au Wei Ming graduated from Singapore Polytechnic with a diploma in environmental management and water technology. He has a strong passion for structural design and environmental science. He has been involved during his course of study, he had his internship in Public Utility Board and gained an understanding of the environmental problems and its impact. He noticed that by reusing municipal wastes is a sustainable way that plays a vital role in conserving landfill spaces.

Letter of Transmittal Final

14 March 2018
Mr. Huge Lim
Building and Construction Authority
52 Jurong Gateway Road #11-01
Singapore 608550

Dear Mr. Lim,

RE: Proposal for Incorporating Plastic Waste into Concrete
Enclosed for your kind consideration is the following proposal for introducing a new design of green concrete through partial replacement of aggregates with plastic waste to Singapore’s construction industry. This proposal has been prepared in response to your letter of authorization for the report.

The report consists of a description of the current situation regarding plastic waste, the rationale behind the proposed solutions, an evaluation of the benefits, suggested alternative solutions and a detailed summary of all related primary and secondary research. We target to reduce the plastic waste in Singapore and we have provided information on the methods to integrate plastic waste into concrete, and an analysis on how plastic waste behaves in concrete.

We would like to express our gratitude to you for taking the time to read this proposal. Your consideration of our suggestions in the integration plastic waste into concrete is greatly appreciated. If you have any question regarding the information on the report, feel free to contact us and we look forward to working with you.


Sincerely,
Serena Koay
On behalf of Team H.S.M                                                             

Friday, 6 April 2018

Analytical Reflection

The teams that presented in the showcase have used various audio and visual to aid in their presentation. Some teams even compiled a video to prove to the audience about the effectiveness of their product.

Personally, I feel that the team, Eco-road, had given an excellent presentation as it was very well rounded and informative. Their slides were very neat and well planned which showed their thought process, and this further enhanced the impact of their presentation. The presenter that did the introduction has lightened up the mood of the audience by incorporating humour into her introduction, and this immediately captured the attention of the restless audience.

The presentation was clearly well rehearsed and all the speakers displayed immense confidence when speaking. The team members have also memorised the sequence of their slides and this assisted them to appear professional.

One particular slide that left a deep impression was the slide showing a little girl named Nara, standing in the midst of a landfill. I think that this slide made a significant impact on the presentation as it would touch the heart of most people. Moreover, the enthusiastic presenter used the tone of his voice and took the impact of the picture to a higher level. However, I do agree with the judges and they could have used a more relevant picture to convey their message.

In my opinion, the composure and confidence of the speakers paired with their neat and simple slides combined with the impactful photo definitely raised the overall effectiveness of their proposal.  They have shown me an excellent example of a well-executed presentation, and I hope that one day I would be able to present at that level.

Monday, 2 April 2018

Critical Reflection

Looking back at my objectives for this module, I wanted to improve my writing and presentation skills. Personally, I feel that I have achieved my goals as I have the chance to write a full technical report with the help of my group. The final presentation also gave me a chance to brush up on my presentation skills as I have practised for the final presentation with some of my classmates, and this has improved my self-confidence as they have given me valuable feedbacks. I would like to integrate the skills that I have learnt in the module into my daily life as it can help me to continuously improve my ability in writing and public speaking.

The main challenge in writing the report is due to the hectic schedule of my group members. As the three of us are in different project groups for other modules, it was hard for us to meet up and discuss the direction of this report. On top of that, some of us have external commitments which further limit our discussion time. This caused my team to have a lack of communication. Therefore, my team decided to split the report evenly and compile it at a later date and this lead to inconsistent work quality as we had different ideas of the project direction.

I have learned that effective communication is a crucial element in a group work. Despite the group works that we have done previously in this undergraduate course, we tend to forget that communication is a significant aspect of the project. This course has taught me of the importance of constant and effective communication between people. Overall, I feel that I have became a better writer and presenter.

Commented:
Umar
Shih Chieh
Haziq



Thursday, 15 March 2018

Personal Statement Draft 1

Au Wei Ming graduated from Singapore Polytechnic with an in diploma in environmental management and water technology. He has a strong passion for structural design and environmental science. He has been involved during the course of study, he had his internship in Public Utility Board and gained an understanding of the environmental problems and its impacts. He realised that by reusing municipal wastes is a sustainable way that plays a vital role in environmental sustainability.

Executive Summary Draft 1

This report was written in response to develop a solution for an engineering problem. In this proposal, the team presents a method to incorporate plastic waste into concrete. Building and Construction Authority has been urging the stakeholders in the construction industry to use waste as a construction material, providing a sustainable construction in the construction industry in Singapore. Therefore, the team is proposing to incorporate 30 – 40% of plastic waste into concrete.
This proposal will detail the effectiveness of incorporating plastic waste into concrete. The team suggests to partially replacing aggregates with shredded plastic waste and discusses its benefits and limitations. Carbon nanotubes can be added in as a supplementary material to meet any specific design requirements.
An evaluation of the benefits and possible limitations to these proposed solutions has also been included in this report.


Letter of Transmittal Draft 1

14 March 2018
Mr. Huge Lim
Building and Construction Authority
52 Jurong Gateway Road #11-01
Singapore 608550

Dear Mr. Lim,

RE: Proposal for Incorporating Plastic Waste into Concrete
Enclosed for your kind consideration is the following proposal for a new method of creating concrete in Singapore. This proposal has been prepared in response to your letter of authorization for the report.

The report consists of a description of the current situation regarding plastic waste, the rationale behind the proposed solutions, an evaluation of the benefits, suggested alternative solutions and a detailed summary of all related primary and secondary research. We target to reduce the plastic waste in Singapore and we have provided information on the methods to integrate plastic waste into concrete, and an analysis on how plastic waste behaves in concrete.

We would like to express our gratitude to you for taking the time to read this proposal. Your consideration of our suggestions in the integration plastic waste into concrete is greatly appreciated. If you have any question regarding the information of the report, feel free to contact us and we look forward to working with you.


Sincerely,
Serena Koay
On behalf of Team H.S.M       


Monday, 12 March 2018

Reader's Response Final

In the article “Duo Turned Plastic Waste into a Concrete Idea,” Goy (2016) explains that the company BlueRen discovered a method of integrating carbon nanotubes from converted plastic waste into cement through a sustainable approach. The article quotes co-founder Aravind Muthiah, who explains that their “technology is about upcycling, and converts plastic waste into high-value products.” The process turns plastics into hydrocarbon gases, creating the carbon nanotubes. Carbon nanotubes are beneficial due to their characteristics that can aid in the reduction of cement by 30% in concrete. Despite the multiple benefits, usage is constrained as the nanotubes are expensive and release harmful gases. To combat these issues, BlueRen developed a recycling process using an alternative mineral as a catalyst that is less harmful to the environment. BlueRen plans to expand on its prototype and to commercialize its technology. While the author mentioned the multiple benefits of carbon nanotubes, there are still significant environmental impacts from plastic recycling that the author did not discuss in detail.

One example of the environmental impact that the author did not mention is the production of volatile organic compound (VOC). According to Soffar (2016), VOC is one is the environmental impacts of melting plastic. Government of Canada stated that VOCs are organic compounds that have high vapour pressures and can evaporate readily into the atmosphere. When VOCs are released into the atmosphere, they are one of the main sources for the formation of ground-level ozone and its particulate matter causes smog. Furthermore, VOCs are also toxic to plants and animals that are near to the pollutant origin
. Usage of the recycled plastics containing VOCs poses a serious health risk to users.

The production of plastic resin is another example of environmental impacts from the manufacturing and recycling process. They can seep into food that is stored in the recycled plastic containers. The amount of harmful chemicals that users absorb can increase based on certain factors like temperature, types of plastic and the plastic age. This environmental issue is related to the health issues and it causes damages to the liver, kidneys and central nervous system. 

Another source of environmental impact is the unrecyclable plastic waste found during the recycling process. Hartman (2017) mentioned that recycling centre employees might find unrecyclable plastics and discard them improperly. Unrecyclable plastic includes plastic that consists of food waste or debris. Plastic, in general, are not considered under hazardous waste and recycling it is not mandatory, such waste can be improperly discarded and the plastic waste problem continues. 

Hartman (2017) explained that downcycling is the recycling of plastic into a less valued product than its predecessor. The recycled plastic has limited use as compared to new plastics and other recycled materials. After the plastic has been recycled once, it is usually ineligible for another round of recycling. This would mean that the recycled plastics will eventually end up in the landfill despite having been made into a less useful product. Downcycling is just delaying the inevitable process of plastics ending up in the landfill as the industries constantly demand for new plastic.

In general, BlueRen’s technology is about converting plastic waste into a high-value product and this technology will eliminate downcycling. Although carbon nanotubes can be effective and readily available, the mentioned environmental impacts from plastic recycling should be taken into serious considerations. The continual of recycling plastic will only worsen the impacts that are already present. (567 words)

References:
Bio-tec. (n.d.) Environmental effects of plastic pollution. GoecopureRetrieved, February 04, 2018 from http://www.goecopure.com/environmental-effects-of-plastic-pollution.aspx

Goy. P. (January 11, 2016). Duo turn plastic waste into a concrete idea. The Straits Times.http://www.straitstimes.com/singapore/duo-turn-plastic-waste-into-a-concrete-idea

Hartman, D. (April 24, 2017). The disadvantages of recycled plastics. Sciencing. Retrieved, February 04, 2018 from https://sciencing.com/disadvantages-recycled-plastics-7254476.html

Richards, H. (August 05, 2014 ). Plastic Recycling: The process, advantages and disadvantages. 33rd SquareRetrieved (February 04, 2018) from  http://www.33rdsquare.com/2014/08/plastic-recycling-process-advantages.html

Soffar, H. (July 28, 2016). Plastic recycling advantages and disadvantages. Science Online. Retrieved, February 04, 2018 fromhttps://www.online-sciences.com/industries/plastic-recycling-advantages-and-disadvantages/

Volatile organic compounds overview. (June 22, 2017). Government of Canada. Retrieved February 04, 2018 from https://www.canada.ca/en/environment-climate-change/services/managing-pollution/sources-industry/volatile-organic-compounds-consumer-commercial/overview.html

Volatile organic compounds (VOCs). (August 23, 2017). U.S. National Library of Medicine. Retrieved, February 04, 2018 from https://toxtown.nlm.nih.gov/text_version/chemicals.php?id=31

Zero Waste Singapore. (December 8, 2008). Plastics recycling. Retrieved, February 04, 2018 from http://www.zerowastesg.com/2008/12/08/plastics-recycling/



Sunday, 11 March 2018

Technical Report Draft 1


1. Introduction


1.1 Background

Singapore named the “The Garden City’’ as it is one of the greenest countries in Asia. Thus, Singapore has been emphasizing on waste management as Singapore’s only remaining landfill is Semakau landfill. Semakau landfill is predicted to be filled by the year 2035. Singapore’s population is growing at a staggering rate every year from 4,027.9 million in 2000 to 5,612.3 million in 2017. An increase of 1584.4 million in the past 17 years.The increase in population eventually leads to the incline of solid waste generation. In 2016, there were 7.81 million tonnes of waste being produced as compared to the 7.67 million tonnes in 2015. There is an increase of 140,700 tonnes. Similarly, if this rapid increase in waste generation continues, the landfill would be filled up before the expected year.
National Environment Agency (NEA) conducted several surveys about the different waste type, waste disposed, and waste recycled, waste generated and recycling rates in 2016. Plastic waste is one of the main contributing waste in Singapore as it has one of the highest amount of waste generated and the lowest recycling rate. Examples of plastic waste are takeaway containers, plastics utensils, plates, and cups. In 2016, 822,200 tonnes of plastic waste was being generated, however, only 7% of it was recycled. The remainder is incinerated and then sent to the landfill. The recycling rate of plastic waste cannot keep up with the increase in plastic waste. This causes more and more plastic waste to be sent to the landfill.
In addition, NEA is urging our local construction industry to investigate the usage of recycled and waste materials. Plastic waste can be recycled and be made into other products like carbon nanotubes and different chemical fuel. However, it is not fully utilized due to the difficulties in collecting and sorting plastic waste.
Samwoh Corporation has been carrying out research on repurposing waste materials and incorporating them into concrete. The project team sees the potential of using plastic waste as aggregates in concrete and is going to focus on promoting the possibility of incorporating plastic waste into concrete.

1.2 Problem Statement

Samwoh Corporation should be incorporating 30-40% of plastic waste into concrete as it is environmentally friendly and provides a new purpose for plastic waste. Plastic waste is one of the largest waste contributors and they are not being investigated extensively as a material in green concrete. According to National Environmental Agency (NEA), there were 822,200 tonnes of plastic waste being generated in 2016 and only 7% of them were being recycled resulting in depletion of space in the landfill as our landfill would be filled up by 2035. Looking at the problem, this research team decided that there is a need to incorporate 30-40% of plastic waste into concrete.  This will reduce the amount of plastic waste being sent to landfills and reducing the need for raw materials of conventional concrete.

1.3 Purpose Statement

This report aims to promote the idea of incorporating plastic waste into concrete to Samwoh Corporation which then can be adopted by Singapore’s construction industry. This will reduce the amount of plastic waste needed to be sent to the landfill. The intention is to enhance the understanding of the advantages of plastic waste in concrete.

2. Proposed Solution

Green concrete refers to concrete that has partial or complete replacement of either cement, fine or coarse aggregates with waste or residual products. When the substitution materials are less dense than the conventional materials, lightweight concrete is produced. There are various ways plastic waste can be incorporated into concrete.
Plastic waste can be processed, typically through shredding and low temperature melting. The processed plastic can be used as coarse aggregate replacement in concrete.
Another way of using plastic waste into concrete is to convert plastic waste into carbon nanotubes. Carbon nanotubes are tiny cylinders of carbon atoms. They can be group into two different types of carbon nanotubes which are the single-walled carbon nanotube (SWCNTs) and multi-walled carbon nanotubes (MWCNTs). MWCN is most commonly used as they are cheaper to make and have a better reinforcement in cement concrete. An innovation by technology company called BlueRen believes that more plastic waste can be recycled and the use of cement to make concrete reduced, as carbon can be used as an additive in concrete idea.
The project team is focusing on the process of converting plastic waste into shredded plastic which can be used as a replacement material for coarse aggregates in concrete.

2.1 Benefits

Kumar. P. and Kumar. G (2016) mentioned that in the last 20 years, research on the usage of urban waste in building materials has been increasingly published. Aside from the environmental benefits, the wastes yield positive effects on the properties of the final product. Amidst the municipal solid waste, plastics have received a lot of attention because they are not biodegradable.  Plastic waste has been increasingly used as a partial substitute of aggregates. The usage of plastic waste as aggregates can greatly reduce the weight of the concrete, this is called lightweight concrete.
It is identified that the usage of plastic aggregates can improve the ductility in concrete. Ductility helps the material to stretch under tensile stress, this property very important in the safety of the building. In an event where the building starts to collapse, people in the building still have time to escape as the concrete would deform significantly before reaching failure. Using plastic aggregate is also cost effective and energy efficient. Plastic aggregates can effectively help to maintain the building interior temperature in hot weathers.
According to Sofi. and Jaivignesh. (2016), the incorporation of shredded plastic, properties such as abrasion resistance, impact resistance, ductility, shock absorption, and thermal conductivity can be improved. Apart from the benefits mentioned, Kumar. P. and Kumar. G (2016) also explained that plastics are versatile and it can be customised to meet specific technical requirements. They have a lighter weight than other materials, therefore, reducing the fuel consumption during transportation. Plastics are very durable and can last a very long time. Moreover, they also have great resistance against chemical, water, and impact. Most importantly, they cost less to produce than traditional concrete. This serves as a way to improve the properties of concrete and act as a solution to the disposal of plastic to some extent.
Samwoh can become one of the leading construction companies in Singapore to use lightweight concrete effectively. Lightweight concrete can be used as non-loadbearing concrete such as concrete panels that are used in facades. By using shredded plastics as an aggregate, Samwoh can bring down the cost of producing concrete as aggregates are relatively pricier than plastic wastes. Samwoh can have a centralised plastic waste collection centre to collect plastic waste disposed by their employees and use it in their concrete batch. This provides self-reliance, hence, reducing the cost to purchase and transport plastic waste from contractors. Furthermore, this shows that plastic aggregates can also be used as a plastic disposal method in the company.
Goy (2016) mention that carbon nanotubes have many uses as they are light, strong and can conduct electricity well. While Goy (2016) may have mentioned the physical properties of carbon nanotubes, Suhendro (2004) provides even more physical properties of carbon nanotubes to prove that carbon nanotubes are better to add to concrete. Suhendro (2004) states ‘multi-walled carbon nanotubes (MWCNTs) are usually high strength, ductile, crack-free and durable’.

2.2 Evaluation

There are two main disadvantages when it comes to incorporating plastic into concrete. Firstly, plastics have a low bonding property. Hence, it causes the compressive, tensile and flexural strength of the concrete to reduce. The concrete might not be strong enough to be used as a load-bearing beam, even at the higher part of the building. Even with reinforced steel added, normal concrete would be more suitable to support a higher amount of load.
Secondly, plastic wastes have to be cleaned condition before being added to the concrete mixture as aggregates. Therefore, it is a hassle and an additional cost to ensure that plastics are unsullied. The overall cost would also increase when equipment might be required to monitor the gas emission and the presence of toxic and polluting elements. However, this only applies when there heating is required in the process.
Despite the mentioned disadvantages, incorporating plastic waste as aggregates into concrete are extremely effective has numerous advantages, such as the improvement of properties of concrete at a cost-efficient approach. These concretes need not be loadbearing concrete as its decreased strength might make it suitable for places with heavy loads. They can be placed in the higher part of the building where the higher floor would mean that it would be carrying lesser loads. They can be used concurrently as a lightweight concrete for aesthetic purposes in the building, without drastically increasing the total load. High ductility is one of the most useful properties in this concrete, it is useful in harsh conditions as it will expand and contract well, as well as having freeze-thaw resistance.
Aggregates can be partially replaced by plastic waste as it can effectively improve the properties of the concrete and lessen the total weight of the building. The reduction in compressive, tensile and flexural strength can be overcome by placing the concrete at higher levels. So that it does not have to withstand addition load from other floors. The use of waste plastic aggregate can be effectively used because of its properties enhancing and lightweight benefits
There is one major weakness about carbon nanotubes which is barriers to green concrete  Barriers to green concrete, Due to building industry’s profitability, it depends on how quick the construction schedules. The faster the building is being built, the faster they get their profit.  Thus, they prefer not to use green concrete as green concrete requires a life-cycle cost saving from the conversion of material and energy.

3. Methodology

This project team performed primary and secondary research that includes a site visit and online materials from various sources and government organizations.

3.1 Primary Research

The project team had the opportunity to visit Samwoh Research and Development Centre as one of our module site visit. The project team talked to the lab manager, Mr. Teo Yong Boon regarding incorporation of plastic into concrete and there is researches on lightweight aggregates and adding of carbon fibres into concrete. However, there was no information regarding the recycling of plastic waste for concrete.

3.2 Secondary Research

A range of secondary data was obtained from official websites, news articles and research journals. This project team gathered statistics regarding Singapore’s waste generation and recycling rate from National Environment Agency (NEA)’s website. A news article has been published quoting NEA promoting Singapore’s construction industries to incorporate more recycled and waste materials as building materials were used as a motivation to promote our idea to Samwoh Corporation.

4. Conclusion

Research has shown that our only landfill will be fully filled by the year 2035. This project team seeks to reduce one of the main culprit, plastic waste, through promoting the recycling of plastic waste and using them as a material in concrete to our local construction industry. While processing the plastic waste can be costly, we believe that it would reduce the amount of plastic waste and benefit the country in the long run.
In conclusion, it is crucial that Singapore explores new ways of waste management. We believe that our proposed solution will be one of the stepping stones towards reducing the amount of plastic waste sent to landfill.

Technical Report Final

1.0 Introduction 1.1 Background This proposal is developed in response to the call for engineering problem solution. for creating sol...