INTERNATIONAL JOURNAL OF RESEARCH AND INNOVATION IN APPLIED SCIENCE (IJRIAS)
ISSN No. 2454-6194 | DOI: 10.51584/IJRIAS |Volume IX Issue XI November 2024
Plastic Upcycling by Converting Plastic to Bricks
Eric P. Catalan1, Julius T. Vergara2, Rhea Joy D. Flora3, Mark Joseph C. Tupas4, Niel A. Luceño5
1Industrial Technology Research and Development
2Office of Research, Extension, Training and Innovation/Guimaras State University
3College of Agricultural Sciences/Guimaras State University
4Office of the Research and Development Office/Guimaras State University
5Office of the Research and Development Office/Guimaras State University
DOI: https://doi.org/10.51584/IJRIAS.2024.911049
Received: 12 November 2024; Accepted: 18 November 2024; Published: 21 December 2024
ABSTRACT
This study aimed to explore the potential of upcycling plastic waste by incorporating recycled shredded PET
bottles into cement mixtures for pavement bricks. The goal was to address the persistent demand and supply of
plastics, which frequently contribute to ocean pollution. By substituting traditional aggregates with recycled
PET, the research assessed the water absorption, waste conversion, durability, and practical applications of
using plastic-enhanced cement mixtures in construction. Mixture #2 demonstrated good water resistance while
being lighter than other mixtures, making it an ideal option for applications where reducing weight is critical
without sacrificing too much strength. Mixture #1 had the highest plastic content, making it the most
aggressive in terms of plastic waste conversion. However, the elevated plastic proportion affected its
durability, suggesting it is best suited for projects prioritizing waste reduction over strength. Mixture #4
emerged as the top performer, showcasing the highest durability. Its equal ratio of sand and plastic provided a
well-balanced mix that combined structural integrity with optimal weight and water resistance. This makes it
the most suitable choice for heavy-duty pavement blocks that require long-lasting performance. Mixtures #3
and #4 achieved a balanced integration of sand and plastic, leading to solid structural properties. Mixture #3’s
moderate durability makes it a versatile choice, while Mixture #4’s superior performance highlights the
benefits of a carefully optimized sand-to-plastic ratio.
Keywords: Environment, reuse, plastic materials, waste reduction
INTRODUCTION
This project focuses on the innovative concept of upcycling plastic waste by converting it into durable and
eco-friendly bricks. This is an innovative approach to addressing plastic pollution and promoting sustainable
construction practices by converting plastic waste into valuable recreational materials such as pavement bricks
it contributes to both environmental conservation and the advancement of the circular economy.
The Philippines, with a population of over one hundred million, produces over one-third of all oceanic plastic
waste in the world (Washington Post, 2023.) which stems from widespread poverty and corporate interests that
drive the masses to buy small quantities more often. Open dumpsites are also the cause of plastic spills into the
seas and after more than two decades since the enactment of a landmark act, the country has failed to meet
most of the targets outlined in the 2001 legislation, with the increasing environmental concerns surrounding
plastic pollution, there is a growing need for sustainable solutions to manage plastic waste. Upcycling offers a
promising approach to address this challenge by transforming plastic into valuable products like bricks. This
study aims to contribute to the reduction of plastic pollution while providing an alternative construction
material that can potentially replace conventional bricks, thereby conserving natural resources and reducing
carbon emissions.
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INTERNATIONAL JOURNAL OF RESEARCH AND INNOVATION IN APPLIED SCIENCE (IJRIAS)
ISSN No. 2454-6194 | DOI: 10.51584/IJRIAS |Volume IX Issue XI November 2024
Objectives of the Study
General: The project aims to contribute to the reduction of plastic pollution while providing an alternative
construction material that can potentially replace conventional bricks, thereby conserving natural resources and
reducing carbon emissions.
Specific:
1. To develop a cost-effective and environmentally friendly method for converting plastic waste into bricks.
2. To assess the water absorption, waste conversion, and durability of the plastic bricks compared to
traditional construction materials.
METHODOLOGY
Methods
The project utilized simple recycling techniques, which included shredding and mixing it with cement and
sand to process plastic waste into brick-like shapes. This project will specifically utilize the plastic
Polyethylene Terephthalate more commonly known as PET as it is the most widely used thermoplastic
polyester and should be considered for recycling. PET has excellent mechanical capability and dimensional
stability when it is subjected to varying loads, which is why it is highly considered in concrete mixes. Some
tests will be performed to evaluate the concrete workability of the bricks. These tests are based on ASTM
C936 which is the Standard Specification for Solid Concrete Interlocking Paving Units. A compression
molding machine was employed in the fabrication process the molding machine is designed for producing
paving bricks from plastic waste is a specialized industrial equipment used to shape and solidify mixtures of
recycled plastic and other binding materials into durable construction blocks.
Different kinds of mixture ratios were applied, and the shredded pieces of PET, each approximately cut to a
size of 5mm were meticulously prepared for treatment to ensure uniformity throughout the experimental
process. These small consistent fragments are crucial in maintaining the integrity and performance of the
material when integrated into construction applications to ensure consistent and accurate measurement, each
component (Cement. Sand, and Shredded PETs) was quantified using a standardized container in this case it
was a 4-liter bucket. This consistent form of measurement is essential for maintaining the proportions required
for optimal material performance. The treatments consist of four block mixtures, each mixture contains a
different proportion of Cement, Sand, and Shredded PETs.
Materials
Provided below is the complete list of materials
1. Portland cement
2. Mixing sand
3. Shredded PET bottles (approximately 5mm in size)
4. 4-liter bucket
5. Shovel
6. Mixing pad
Table 1. Treatments.
Treatments Cement Plastic Sand
Mixture #1 1 3 4
Mixture #2 1 3 3
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INTERNATIONAL JOURNAL OF RESEARCH AND INNOVATION IN APPLIED SCIENCE (IJRIAS)
ISSN No. 2454-6194 | DOI: 10.51584/IJRIAS |Volume IX Issue XI November 2024
Mixture #3 1 2 3
Mixture #4 1 2 2
RESULTS AND DISCUSSIONS
Water Absorption
Among the mixtures, Mixture #4 stands out as the most suitable option for durable pavement blocks, balancing
weight and water resistance. Mixture #2 also showed good water resistance but is lighter and might be better
for situations where weight savings are a priority. Mixture #1, with the highest water absorption, may not be
ideal for high-durability applications, while Mixture #3 offers moderate characteristics that may fit niche
needs. This implies that the amount of plastics and sand contributed to the water absorption of bricks.
As reported by Lawrence and Achanit Lawrence & Achanit (2019), while the overall water absorption capacity
of compressed stabilized earth blocks did not vary significantly with the addition of sand, a specific blend
containing 20% sand exhibited the lowest water absorption capacity. This suggests that optimizing sand
content can enhance the moisture resistance of cement-based materials. Similarly, Subramanian and Ku
Subramanian & Ku (2019) noted that increasing sand content in a cement-clay matrix reduces the water-
holding capacity, indicating a potential strategy for managing water absorption in cement mixtures.
The incorporation of recycled plastics into cement mixtures also shows promise for reducing water absorption.
Dawodu et al. Dawodu et al. (2023) reported that paving stones made from waste plastics exhibited a higher
water absorption resistance compared to traditional cement mixtures. This is particularly relevant for
applications in flood-prone areas, where materials with lower water absorption are advantageous. Additionally,
Thorneycroft et al. Thorneycroft et al. (2018) found that while the use of plastics as a partial sand replacement
can decrease compressive strength, it can also lead to lower water absorption due to the hydrophobic nature of
plastics, which may create less porous structures.
Table 1. Water Absorption Test Result.
Treatments Average Weight of Paver Block Average Weight of Paver Average Percentage of
Before submersion in water (in Block After submersion Water Absorbed
Kg) in water (in Kg)
Mixture # 1 2.1 2.44 14%
Mixture # 2 1.58 1.7 7.01%
Mixture # 3 1.75 1.98 12%
Mixture # 4 2.13 2.29 7.30%
Waste Conversion
The data suggests that bricks incorporating plastic waste can effectively reduce the use of sand, conserve
natural resources, and manage plastic waste. Mixture #1 is the most aggressive in terms of plastic waste
conversion, while Mixtures #3 and #4 offer a balanced approach. Such strategies can play a crucial role in
sustainable construction and waste management efforts, contributing positively to the environment.
Research indicates that various types of plastics, such as polyethylene and polyvinyl chloride, can be
effectively utilized in brick production, either as a primary material or as a composite with traditional materials
like sand and cement (Narayan et al., 2023; Rahman, 2024; Rahman, 2022).
Moreover, the environmental implications of using plastic waste in brick production are profound. By
repurposing plastic waste, the construction industry can significantly reduce its carbon footprint and reliance
on conventional raw materials. Research highlights that the incorporation of waste plastics into brick
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INTERNATIONAL JOURNAL OF RESEARCH AND INNOVATION IN APPLIED SCIENCE (IJRIAS)
ISSN No. 2454-6194 | DOI: 10.51584/IJRIAS |Volume IX Issue XI November 2024
manufacturing can lead to lower production costs and reduced environmental impact, making it a viable
alternative to traditional methods (Rahman, 2022; Lamba et al., 2021; Verma et al., 2022).
Table 2. Waste Conversion Result.
Treatments Composition per kg
Cement Sand Plastic
Mixture # 1 7.55 kg 22.65 30.2
Mixture # 2 7.55 kg 22.65 22.65
Mixture # 3 7.55 kg 15.1 22.65
Mixture # 4 7.55 kg 15.1 15.1
Durability
The durability of the eco-bricks varies significantly depending on the mixture composition. Mixture #4
demonstrates the highest durability, indicating that an equal ratio of sand and plastic contributes positively to
structural strength. Mixture #1’s poor performance under impact suggests that very high plastic content can
weaken the brick, while mixtures #2 and #3 show that a balance between sand and plastic is crucial for
durability. These insights are vital for optimizing eco-bricks that are both environmentally sustainable and
structurally sound.
Studies have shown that the compressive strength of bricks can be significantly influenced by the type and
proportion of plastic waste used. For instance, Narayan et al. found that the compressive and split tensile
strength of plastic bricks improved when the percentage of plastic was reduced from 25% to 20% (Narayan et
al., 2023). Similarly, Rauniyar reported that a specific mix of plastic waste achieved a compressive strength of
426 kg, indicating a robust performance compared to traditional materials (Rauniyar, 2024). Furthermore,
research by Mahyoub demonstrated that while increasing the ratio of plastic to sand decreased compressive
strength, the overall weight of the bricks was reduced, which can be beneficial for certain construction
applications (Mahyoub, 2023).
This aligns with findings from Ikechukwu and Naghizadeh, who emphasized the durability of waste plastic
bricks produced from a blend of scrap PET plastics and foundry sand (Ikechukwu & Naghizadeh, 2022). The
incorporation of plastic waste not only contributes to mechanical strength but also aids in reducing the
environmental impact associated with traditional brick production.
Table 3. Durability Test Result.
Treatments Number of Paver Number of Blocks with Average percentage from
blocks significant damage drop-test
Mixture # 1 6 4 33.33%
Mixture # 2 6 2 66.67%
Mixture # 3 6 3 50%
Mixture # 4 6 1 83.33%
CONCLUSIONS
This research highlights the promising potential of integrating recycled plastics into construction materials.
The successful use of PET bottles as aggregates not only contributes to reducing plastic pollution but also
aligns with sustainable practices in the construction industry. The outcomes point to a viable pathway for
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INTERNATIONAL JOURNAL OF RESEARCH AND INNOVATION IN APPLIED SCIENCE (IJRIAS)
ISSN No. 2454-6194 | DOI: 10.51584/IJRIAS |Volume IX Issue XI November 2024
reducing dependency on traditional raw materials, promoting a circular economy, and decreasing the
environmental footprint of construction projects. The findings encourage further exploration into eco-friendly
alternatives, supporting a shift towards greener and more resilient building materials.
Additional evaluations under diverse environmental conditions (e.g., extreme weather, load-bearing tests) are
recommended to fully understand the long-term performance of each mixture. Future studies could also
investigate different types of recycled plastics and their impact on brick properties.
ACKNOWLEDGEMENT
The author would like to extend thanks to the university for funding this research study.
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