Study on Mechanical Properties of Concrete Using Plastic Waste as an Aggregate

Disposal of large quantity of plastic causes land, water and air pollution etc.., so a study is conducted to recycle the plastic in concrete. This work investigates about the replacement of natural aggregate with non-biodegradable plastic aggregate made up of mixed plastic waste in concrete. Several tests are conducted such as compressive strength of cube, split tensile strength of cylinder, flexural strength test of prism to identify the properties and behavior of concrete using plastic aggregate. Replacement of fine aggregate weight by 10%, 15%, 20% with Plastic fine (PF) aggregate and for each replacement of fine aggregate 15%, 20%, 25% of coarse aggregate replacement also conducted with Plastic Coarse(PC) aggregate. In literatures reported that the addition of plastic aggregate in concrete causes the reduction of strength in concrete due to poor bonding between concrete and plastic aggregate, so addition of 0.3% of steel fiber by weight of cement in concrete is done to improve the concrete strength. Totally 60 cubes, 60 cylinders and 40 prisms are casted to identify the compressive strength, split tensile strength and flexural strength respectively. Casted specimens are tested at 7 and 28 days. The identified results from concrete using plastic aggregate are compared with conventional concrete. Result shows that reduction in mechanical properties of plastic aggregate added concrete. This reduction in strength is mainly due to poor bond strength between cement and plastic aggregate.


Introduction
In civil engineering construction use of shredded plastics has increased drastically as a partial replacement of aggregates. As it is an added advantage in terms of environmental and potential economic consideration incorporation of waste in concrete increases [1][2][3][4]. Plastic can be incinerated with energy recovery, if material recycling is not feasible. Air pollution may cause and results in acid rain because of waste incineration [6,9]. Past investigations suggest that partial replacement of aggregate of concrete with waste plastic can improve properties such as abrasion resistance, impact resistance, ductility, shock absorption and thermal conductivity [10]. It also shows that addition of plastic to concrete causes some reduction in mechanical properties such as compressive strength, split tensile strength, flexural strength [5,7,8]. Literature reviews suggest that addition of steel fiber in normal concrete improves these mechanical properties. Taking the advantages of this, steel fiber is added to plastic waste aggregate concrete to make steel fiber reinforced waste plastic mix concrete. [12,13]

Water
Potable water was used in the experimental work for both mixing and curing purposes

Plastic waste
Waste plastic represents the discarded waste from plastic containers that were collected from plastic manufacturing plants located in Vellore. After collection of waste plastic, Plastic aggregate is obtained by crushing the plastic waste [11].

Mix Design
The M25 grade concrete mix proportions were arrived as per the Indian Standard IS: 10262-2009. Replacement of fine aggregate weight by 10%, 15%, 20% with Plastic Fine (PF) aggregate and for each replacement of fine aggregate 15%, 20%, 25% of coarse aggregate replacement also conducted with Plastic Coarse (PC) aggregate.0.3% of steel fiber is added by weight of cement.

Experimental Work
The experimental work is carried out in order to find out the mechanical properties of the concrete. concrete was calculated and the average of three specimen compressive strength was estimated at different curing age of all the concrete mixtures. By using the result plotted the graph and shown in Figure 1 and Figure 2.

Discussion on compressive strength test results
concrete was lowered by the addition of plastic. The reduction loss may be attributed to the poor bond strength between plastic particles and concrete.

Split tensile Strength
The concrete is weak in tension. There is no direct method to find out the splitting tensile strength of concrete. So the cylinder of 100mm Ø and 200mm depth were casted and cured into 7 days and 28 days. The specimens are allowed to dry the surface moist the compression testing machine. Load is concrete was calculated and the average of three specimen compressive strength was estimated at different curing age of all the concrete mixtures. By using the result plotted the graph and shown in th day).

Discussion on compressive strength test results.
The compressive strength of waste concrete was lowered by the addition of plastic. The reduction is being in the range of 9 to 17 %. This loss may be attributed to the poor bond strength between plastic particles and concrete.
ak in tension. There is no direct method to find out the splitting tensile strength of concrete. So the cylinder of 100mm Ø and 200mm depth were casted and cured into portable 7 days and 28 days. The specimens are allowed to dry the surface moisture and kept longitudinally in Load is applied at the longitudinal surface of the specimen and the concrete was calculated and the average of three specimen compressive strength was estimated at different curing age of all the concrete mixtures. By using the result plotted the graph and shown in of waste plastic used 9 to 17 %. This ak in tension. There is no direct method to find out the splitting tensile strength of portable water for ure and kept longitudinally in applied at the longitudinal surface of the specimen and the

Discussion on split tensile strength test results
concrete was lowered by the addition

Flexural strength
The flexural strength was conducted on prisms of days to find out the behavior of beams. The specimen was mounted on the universal testing machine and two point loading was applied hydra obtained graph has been plotted as shown in Figure 5 and Figure 6 ultimate load is found at which the specimen may crack. From the results obtained graph has been 3 and Figure 4. th day).
iscussion on split tensile strength test results. The split tensile strength of waste plastic used concrete was lowered by the addition of plastic. The reduction is being in the range of 10 to 24 %.
The flexural strength was conducted on prisms of size 100 × 100 × 500 mm at the age of 7 days of beams. The specimen was mounted on the universal testing machine and two point loading was applied hydraulically which was increased until failure. From the results shown in Figure 5 and Figure 6.
ultimate load is found at which the specimen may crack. From the results obtained graph has been The split tensile strength of waste plastic used being in the range of 10 to 24 %.
× 100 × 500 mm at the age of 7 days and 28 of beams. The specimen was mounted on the universal testing machine

Conclusion
At all curing ages the compressive strength decrease is mainly due to adhesive strength between the surface of the waste plastic and cement paste. The hydration of cement is also restricted by means of using waste plastic which it is a hydrophobic material. In addition waste plastic is Due to presence of plastic aggregate t relatively less when compared with effectively used as aconservation point of view,