LEGOBLAS (Lego Bata Plastik) Eco-friendly Solution for Plastic Waste Accumulation

The problem of waste generated by activities at UNESA can threaten the health of the environment and the welfare of the surrounding community. A solution is needed to overcome the waste problem in the UNESA environment. One solution that can be taken is to make paving blocks from plastic waste, or it can be called LEGOBLAS. This research aims to improve previous research and utilize plastic waste to be used more beneficially. In this study, data was collected through LEGOBLAS testing, which included testing for compressive strength, absorption, slipperiness, and heat strength. In addition, supporting data is also collected through external observation and LEGOBLAS measurements, including the length, width, height, and mass of LEGOBLAS. The method applied in this study is descriptive quantitative; the form of data presentation is in the form of numbers, which are then analyzed using the LEGOBLAS test. Making eco-friendly LEGOBLAS goes through several stages, including sorting plastic waste, melting plastic waste, and printing LEGOBLAS. Melting plastic using used cooking oil aims to prevent the chlorine content from being released into the air so that it is environmentally friendly. Compressive strength testing using a Compression Testing Machine, Slippage test using a Surface Roughness Tester, Absorbency Test by immersing LEGOBLAS in water for 10 minutes, and Heat Resistance Test by baking for 12 hours at 38°C. Action is needed to reduce this plastic waste; one way to reduce this plastic waste is by making LEGOBLAS a utilization of plastic waste.


Introduction
Plastic waste is a type of waste made from synthetic polymer materials that are difficult to decompose naturally.Plastic waste can be in bottles, food packaging, plastic bags, styrofoam, and other plastic products.One of the characteristics of plastic waste is its long durability, so it takes a very long time to decompose in nature.One type of plastic is PET plastic (PolyEthylene Terephthalate), the most common type of plastic used to manufacture bottles and beverage containers.PET is a thermoplastic polymer that is strong, lightweight, and resistant to chemical attack, making it suitable for food and beverage packaging.Unfortunately, the need for more awareness of proper plastic waste management has increased plastic waste that pollutes the environment, especially the oceans and land.
One solution that can be taken is to make paving blocks from plastic waste.Concrete brick (paving block) is a composition of building materials made from a mixture of Portland cement or similar hydraulic adhesives, water, and aggregate with or without other additives, which do not reduce the quality of the concrete bricks [1].Paving blocks are widely used because they can withstand loads within certain limits and are easy to install.In addition to these advantages, they were paving blocks.
Others in terms of the economics of its maintenance, the artistic aspect of the exterior of a building does not require heavy equipment.It can also be mass-produced, viewed from an environmental perspective as a water absorption system [2].The use of paving blocks has several advantages; among others, they can be mass-produced, can be applied to road construction without requiring special skills, can be under normal loading conditions, paving blocks can be used during service life, and paving blocks are not easily damaged, and do not cause noise and dust disturbances during construction [3].
Using plastic waste as raw material for bricks can reduce the amount of plastic waste dumped into the environment and help reduce environmental problems caused by waste [4].Paving blocks are an alternative cover or hardening of the soil surface, which can be selected at various levels of quality [5].Grade A is used for roads, grade B for parking equipment, grade C for pedestrians, and grade D for parks and other uses.With this quality choice, paving blocks can be adapted to functional requirements and provide optimal performance according to their use.
The previous research conducted by Theresia et al. in 2023 was research on recycled plastic waste paving blocks, which were tested for their compressive strength and absorption at different paving ages [6].They only use a plastic composition of 0.2 to 0.8 of the cement and aggregate used, so the dominant material is still the same as conventional paving [6].The research by Theresia et al. did not review the aspects of paving block resistance to heat and the surface smoothness of paving blocks when exposed to slippery liquids because paving blocks made of plastic cannot withstand excessive heat.
LEGOBLAS are paving bricks made from melted plastic.LEGOBLAS is very important to research because it is made of 100% plastic without adding cement or aggregate.It can be proven by several stages of testing that LEGOBLAS has superior capabilities to conventional paving stones.The research scheme we will do this time is to test paving bricks' compressive strength, absorption, heat resistance, and surface smoothness.
Based on the description above, it is necessary to conduct further research on LEGOBLAS to obtain accurate data regarding the advantages and disadvantages and determine the location suitable for using LEGOBLAS.

Making process Preparation of Tools and Materials
The tools used in this study include:

Steps
In making this eco-friendly LEGOBLAS (Lego Brick Plastic), it is designed through the following steps (see Figure 1).This LEGOBLAS research was carried out in three locations: the LEGOBLAS product manufacturing and the LEGOBLAS testing locations.The location for making LEGOBLAS is at Surabaya State University, which is more precisely in the Materials Physics Laboratory, while the LEGOBLAS testing locations are at the UNESA Materials Physics Laboratory, UNESA Civil Engineering Concrete Laboratory, and ITS Materials and Metallurgy Laboratory.LEGOBLAS research will be carried out for almost four months, from July to October.
LEGOBLAS, which is made of plastic, must be tested to find out its capabilities possessed by LEGOBLAS.The LEGOBLAS test was carried out in 4 different tests.The four LEGOBLAS tests can be seen in Figure 1.
This LEGOBLAS research was carried out in three locations: the LEGOBLAS product manufacturing and the LEGOBLAS testing locations.The location for making LEGOBLAS is at Surabaya State University, which is more precisely in the Materials Physics Laboratory, while the LEGOBLAS testing locations are at the UNESA Materials Physics Laboratory, UNESA Civil Engineering Concrete Laboratory, and ITS Materials and Metallurgy Laboratory.LEGOBLAS research will be carried out for almost four months, from July to October.
LEGOBLAS, which is made of plastic, must be tested to find out its capabilities possessed by LEGOBLAS.The LEGOBLAS test was carried out in 4 different tests.The four LEGOBLAS tests include:

LEGOBLAS pressure test
This test determines LEGOBLAS's ability in terms of pressure because LEGOBLAS will be used on public roads that many people will step on.This test is crucial so that LEGOBLAS can be installed in the right place according to its compressive strength.The location for this test is the UNESA Civil Engineering Concrete Laboratory.This test is carried out using a Compression Testing Machine to obtain data on the compressive strength of LEGOBLAS in kilograms and the cross-sectional area subjected to the LEGOBLAS surface by Compression Testing Machine.Both of these data will be calculated using a physics formula so that the compressive strength of LEGOBLAS can be obtained.The formula used is as follows:

LEGOBLAS dexterity test
The slippage test on LEGOBLAS is essential to determine its surface roughness value on LEGOBLAS and compare it to conventional paving bricks.Safety first is the reason for this test; when the LEGOBLAS roughness value is the same or almost the same as conventional bricks, LEGOBLAS is considered successful in terms of safety first.This test will be carried out at the ITS Materials and Metallurgy Laboratory using a surface roughness tester.LEGOBLAS will be smeared with various materials before being tested using the tool.The following are the materials to be tested and the test steps:

LEGOBLAS Absorption Test
This test determines how LEGOBLAS responds when exposed to water because it does not rule out the possibility of LEGOBLAS being exposed to rain.This test is also carried out as a condition for paving bricks, according to SNI.The formula used to determine the absorption power of LEGOBLAS is as follows: The steps taken for this test are by the flowchart (Figure 4).

LEGOBLAS Heat Resistance Test
This test is to find out how LEGOBLAS is resistant at specific temperatures.This test is carried out to determine which places or roads are suitable for using LEGOBLAS as a substitute for conventional paving bricks.This test was carried out using the Unesa Physics Materials Laboratory oven.The following is the procedure for the LEGOBLAS heat resistance test:

Estimated Cost
Consider all consumable aspects, such as used cooking oil and LPG.The details of one 3kg LPG can produce 17 LEGOBLAS, and one liter of used cooking oil is used to mix 8 LEGOBLAS.From these details, to make one meter2 LEGOBLAS costs Rp. 68,000, with every meter square, there are 50 LEGOBLAS pieces.Generally, conventional bricks are divided into three types, namely K250, K300, and K400.The higher the number, the higher the price.The price details per meter square are K250: IDR 85,000/m2, K300: IDR 95,000, K400: IDR 115,000.

Data Analysis
The Research Team has carried out the making and testing of LEGOBLAS before, namely in May 2023.The tests carried out are still simple and need to use tools that are accurate and can be accounted for.Below are the test results.This is commonly defined as the resistance to failure under the action of compressive forces, and it is a significant parametric property that engineers use to gauge the performance of the material throughout service conditions.Jassi [7] have opined that concrete resistance to impact and abrasion is associated with its compressive strength and the type of aggregate.
Generally, the compressive strength of the specimens increased when the plastic waste was used to replace cement.This clearly shows that concrete paving blocks have inferior compression than RPW paving blocks using the same mix ratio of 1:1:2.According to Huang et al [8], this could be credited to the increase in adhesive strength between the surface area of the waste plastic and neighboring aggregate particles.Quarcoo [9] observed in their experiment that the subsequent increase in contact area would usually result in strength improvement.Results, however, vary with that of Frigione [10] who partially substituted 9%-25% by weight of cement with low-density

LEGOBLAS
oven 12 hours at 38 o C heat resistance test results polyethylene (LDPE)waste after 28 days of curing age.Youssef et al [11] also observed in his study, after replacing sand with waste polyethylene, plastic concrete's compressive strength and splitting tensile strength were 0.4-1.9%lower than that of the Control but with somewhat higher ductility.The results of the LEGOBLAS pressure test still use humans; LEGOBLAS is pressed by being stepped on by humans.The humans used are two different people weighing 55 kg and 90 kg, respectively.From the test results, LEGOBLAS can withstand the pressure load of 2 people with a total weight of 145 kg in a legoblast state placed on the ground.The results of the LEBOBLAS test were then compared with the ability of conventional paving bricks, which were subjected to the same treatment, namely being stepped on by two people with a total weight of 145 kg.The comparison obtained is that the two paving bricks (LEGOBLAS and conventional) have the same results, namely they do not crumble when stepped on with a total weight of 145 kg, indicating that LEGOBLAS has the same ability as conventional paving bricks in this simple test.The LEGOBLAS heat resistance test results are carried out simply by placing LEGOBLAS in a place exposed to direct sunlight and in a dim place and then comparing the results after being placed for 12 hours.Based on the table, it is found that LEGOBLAS has good performance, meaning that there is no melted LEGOBLAS surface.These results indicate that LEGOBLAS is resistant in the open with a temperature of 33°C.LEGOBLAS is considered safe to use because it does not melt, which could interfere with the comfort and safety of road users.
Asserted that RPW demonstrates the lowest water absorption because of its hydrophobicity having soaked results from 6 h to 1 week between 0.0-1.0%.Sharma and Batra [12] stated that the moisture absorption capacity of a paving block should not be in excess of 6% by mass, and in individual samples, it should be limited to 7%.More so, the range for LWC may vary from a few percentages to as high as 45%, depending on the aggregate pore structure [13].The average saturated surface dry density range of 1064.89-1074.40kg/m3 was within the specified threshold values of 500-1900 kg/m3 recommended for LWC.Also, the obtained porosity values of 19.22% for LH and 13.72% for HP are less than the Control result of 35.35% and other limits reported in most literature [14].The LEGOBLAS absorption test is carried out simply by measuring the dry weight of LEGOBLAS and then soaking it in water for 30 minutes.After soaking, the wet weight of LEGOBLAS is carried out.The results of this test found that the average absorption power of LEGOBLAS increased at an older age.This test then compares the absorption capacity of LEGOBLAS with the absorption capacity of conventional bricks with grade C, namely for pedestrians.According to SNI, the absorption capacity of C-quality paving bricks is 8%, so in terms of absorption, LEGOBLAS bricks are still below conventional bricks.

Hypothesis
Based on the results of simple tests by the previous Research Team, the hypothesis is that LEGOBLAS is the most appropriate substitute for conventional paving bricks and has the advantage of being cheaper to produce than the selling price of paving bricks in general.
The position of LEGOBLAS is based on simple test results, namely that it is equivalent to conventional bricks with type-C bricks, namely those used for pedestrians.

Conclusion
Based on the analysis and discussion above, it can be concluded that plastic waste is difficult to decompose, causing the accumulation of waste.Action is needed to reduce this plastic waste; one way to reduce this plastic waste is by making LEGOBLAS a utilization of plastic waste.Making LEGOBLAS uses a melting technique so it does not cause air pollution.The quality of LEGOBLAS has met the standards from the external aspect, size and compressive strength, heat resistance, and absorption, which are suitable for the function of the paving bricks themselves.However, the tests carried out are still in the simple test stage.Therefore, it is necessary to carry out scientific testing using laboratory equipment that can be accounted for so that the ability of LEGOBLAS can be known accurately.
Fc' = press hard (MPa) P = compressive load (N) A = pressure area (mm²)The steps carried out in the LEGOBLAS pressure test are by the flowchart (Figure2).

Figure 4 .
Figure 4. Steps for the LEGOBLAS Absorption Test.

Table 3 .
LEGOBLAS Heat Resistance Test Data