Comparison of strength and other factors of concrete by replacing normal aggregates with demolished material and plastic aggregate

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1 3rd International Conference on Electrical, Electronics, Engineering Trends, Communication, Optimization and Sciences Comparison of strength and other factors of concrete by replacing normal aggregates with demolished material and plastic aggregate 1 Mrs. Prashika Tamang, 2 Anushiya Pradhan, 3 Kiran Rai, 4 Anisha Upadhyaya, 5 Karuna Chettri Lecture in Dept. Of civil engineering polytechnic 1 2, 3, 4, 5 Diploma Students in Dept. of Civil Engineering, CCCT Polytechnic Chisopani, P.O. Nandugaon, South Sikkim, India Abstract The purpose of this work is to partially replace plastic coarse aggregate and demolished coarse aggregate by 0%, 5%, 10% and 15% in place of normal coarse aggregate in order to gain the strength of normal concrete. Plastic being frequently recycled loses its strength ultimately being a waste, which never decomposes and becomes a problem to environment. So, if plastic used as coarse aggregates in concrete it will make a light weight concrete, which can be used to make heavy structure light [1] resulting in decrease in dead load and reinforcement. Due to lower density it absorbs shocks and resists higher seismic force. Demolished aggregates when replaced in place of normal aggregates come into use which will be saving the landfill and decreases the demolished waste. As demolished aggregate already consist of some proportion of cement, the water consumption is more and cement consumption is less. Various tests are conducted to get the possible outcomes. 2. DEMOLISHED AGGREGATE Concrete is the world s most widely used construction material [3] Concrete debris was collected from the recently dismantled college terrace. It was further crushed by a conventional method of hammering. The aggregates were graded into fine and coarse using sieve analysis. 3. PLASTIC AGGREGATE Plastics collected from the disposal area in and around the college were sorted. Then it was crushed into smaller fractions and was heated at a [4] >250 Celsius temperature so that the brittleness was obtained. After extrusion the molten plastic were cooled down and crushed down to the size of an aggregates. 4. BLOCK DIAGRAM Keywords coarse aggregate; light weight concrete; demolished aggregate; normal concrete 1. INTRODUCTION Demolition of old and deteriorated buildings and their substitution with new ones is a frequent phenomenon today in a large part of the world. The most common method of managing this material has been through its disposal in landfills. In this way huge deposits of construction waste are created, becoming a problem. These results shows that the recycled aggregate that are obtained from site make good quality concrete. Plastics have become the most widely consumed inseparable and integral part in human life. The amount of plastics consumed annually has been growing steadily. Plastics have low density, strength, long life, light weight and low cost. Due to these factors the concrete made by plastics aggregates are lighter than that of normal concrete. [2] Since a complete substitution for natural coarse aggregate was not found feasible, a partial substitution with various percentage of PCA was done. Fig. A. Shows the Block Diagram 5. BLOCK DESCRIPTION A. Concrete Debris and Plastic Collection: We collected concrete debris from recently dismantled college terrace. And for plastics we focused on thermosetting plastics (also known as thermo set which are pre polymers materials which cures irreversibly.) which are soft drinks bottles, plastic bags, packages i.e., Polyethylene Terephthalate. B. Crushing: For crushing of demolished material we used a conventional method of hammering. And for plastics 829

2 aggregates we used heating and cooling process. And then we again crushed it using hammer. C. Grading: For grading of coarse and fine aggregates we used sieving. D. Mixing: Certain proportion of cement sand and coarse aggregates with varying percentages were taken and thoroughly mixed by trowel for certain time. Properties Normal Demolished a. Specific gravity (Fine agg.) b. Impact test (Coarse agg.) E. Casting: For the casting of the cubes we used 10cm x 10cm x 10cm moulds which are made up of cast iron. F. Curing: After casting of cubes we took it out from the mould and took the dry weight and then placed it for curing in curing tank. After the completion of curing we again took the weight of wet cubes. G. Testing: We conducted compression test of the cubes that was cured. H. Evaluation: Comparison between normal demolished and plastics test was done. 6. THE PROPERTIES OF MATERIAL USED. In the present study, the various tests on material such as cement, sand, coarse aggregates and plastic wastes are performed as per the relevant data s. [5] In this work plastics and demolished aggregates were used to produce structural concrete. The following materials were used. A. Cement: the cement used was Portland pozzalona cement. The following are the properties shown in table.1. Table 1: PROPERTIES OF CEMENT DESCRIPTION OF TEST Initial setting time Final setting time TEST RESULT OBTAINED 30min 10 hours Specific gravity 3.15 B. Water: Water used for mixing and curing should be free from injurious amount of oils, acid, salts, sugar etc. The PH value shall not be less than 6. C. Demolished materials: Generally obtained from the dismantled college terrace the following properties were obtained the following are the results of the test conducted on demolished material. Graph A : Specific gravity of fine aggregate: Graph B: Impact test of coarse aggregates: D. Plastic aggregate: The following tests on plastics aggregates were conducted and the results are shown in table 1.2. Table 3: TEST ON PLASTICS AGGREGATES: Properties Normal Plastics a. Specific gravity (Fine agg.) b. Impact test (Coarse agg.) Following are the graph plotted for above table: normal plastic normal demolished Graph C: Specific gravity for plastics: Table 2: TEST ON AGGREGATES 830

3 C. Normal consistency of cement: Since different batches of cement differ in fineness, paste with the same water content differs in consistency. Hence percentage of water in the cement will vary from cement to cement and the quantity of water used in the test will also vary cement paste of normal consistency. The plunger of 10mm diameter is permitted to penetrate up to depth of 5-7mm above the bottom of vicat apparatus. Graph D: Impact test for plastic: 7. IMPORTANCE OF THE TESTS: A. Test on Specific gravity: [6] specific gravity is used to separate deleterious particles, lighter than other particles from good aggregate. It is used in calculating the solid volume of aggregate in concrete mix. The specific gravity ranges from 2.5 to 3.The quantity of gm is taken. In Portland cement concrete the specific gravity of aggregate is used in calculating the percentage voids and the solid volume of aggregate in computation of yield. The specific gravity was calculated using the following formula: For Fine Aggregate: G= (W 2 -W 1 )/(W 4 -W 1 )-(W 3 -W 2 ) Where, W 1 =Weight of beaker W 2 =Weight of beaker + sand W 3 =Weight of beaker+ sand+ water W 4 =Weight of beaker + water For Cement: G= (W 2 -W 1 )/ (W 4 -W 1 )-(W 3 -W 2 ) Where, W 1 =Weight of beaker W 2 =Weight of beaker + Cement W 3 =Weight of beaker + Cement+ Kerosene W 4 = Weight of beaker + kerosene B. Impact test: The property of materials to resist impact is known as toughness. [7] The aggregate should have sufficient toughness to resist their disintegration due to impact. The aggregate impact value is a measure of resistance to sudden impact or shock which may differ from its resistance of gradually applied compressive load. The impact value was calculated using the following formula: Impact Value= (W 2 /W 1 ) x100 Where, W 1 =Weight of dry sample W=Weight of portion passing through 2.36 mm sieve Hence, the demolished aggregate is weaker than the normal aggregate against different mechanical actions as they get crushed more easily. Table 4: CLASSIFICATION OF IMPACT TEST VALUE. IMPACT VALUE CLASSIFICATION <10% Exceptionally Strong 10-20% Strong 20-30% Satisfactory for road surface >35% Weak for road surface D. Initial setting time: Setting time refers to stiffness action of changing from a liquid state to solid state. The setting task measure the time taken for the cement paste to offer a certain degree of resistance to the penetration. It is the period elapsing between the time when the water is added to the cement and the time at which a needle of 1mm 2 section fails to pierce depth about 5mm to 7mm from the bottom of the mould. The minimum initial setting time as specified for ordinary and rapid hardening cement is 30 minutes [8] E. Sieving of fine aggregate: [9] it gives an idea of mean size of particle in the entire body of aggregate. F. Coarse aggregate size: when it comes to the strength of concrete size plays an important role. [10] It affects the workability and strength of concrete. It influences the water demand for the mix. The size of coarse aggregate taken for plastic, demolished and normal aggregate was 12.5mm down size. 8. ADVANTAGES OF THE WORK: PLASTICS: Reusing plastics to manufacture various items of commercial use other than manufacturing aggregates as proposed may give rise to inferior products that ultimately end up as wastes. Hence, there is a scope for managing plastic wastes effectively through the manufacturing of aggregates. DEMOLISHED: There are a variety of benefits in recycling concrete rather than dumping it or burying it in a landfill. Keeping concrete debris out of landfills saves space there. 9. EXPERIMENTAL PROCEDURE FOR DEMOLISHED AGGREGATE. A. Introduction The following describes the experimental work. Firstly, the material, mix proportions, mixing, casting and curing of the specimens are explained. This is then followed by description of types of specimens used, test procedures and test results. B. Mix proportion: The mix proportion used for test was 1:2:4. The total replacement of demolished aggregate was not feasible. So partial replacement by 0%,5%,10%,15% and so on is done. C. Mixing, Casting, and Curing: Initially the dry mix of cement, sand and coarse aggregate with 5% replacement of demolished aggregate was done in 95% of normal course aggregate. It was mixed for about 10 min. Water was added to the dry mix and mixed for 4 min to contain a fresh 831

4 concrete. The slump test was done after mixing. And the fresh concrete was immediately caste into the mould in three layers for cube specimen. The compaction of the specimen, each layer giving 15 strokes by tamping rod was done. Then it was further cured for 3days, 7days, and 28days. 10. TEST PROCEDURE: A. General procedure: The mix proportion of 1:2:4 with 12.5 mm coarse aggregate size with water cement ratio varying from 0.7, 0.8, and 0.9 was used. B. Slump test: It is done to find the workability of the concrete. The following are the results obtained. Factors to be considered for slump test. The difference to the level between the height of the mould and that of the highest point of the concrete is measured. These differences in height are taken as slump of the concrete. If the concrete slump s evenly it is called true slump. If one half of the cone slides down it is called shear slump. Types of concrete 0.7 Slumps in cm 0.9 Average 0.8 5% Plastics % Plastics % Plastics % Plastics In case of shear slump value is measured as the difference in height between the height of the mould and the average value of subsidence. It also indicates that the concrete is non-cohesive and shows the characteristics of segregation. A collapse slump will generally mean that the mix is too wet or that it is a high workability mix for which the slump test is not appropriate. Table 5: SLUMP TEST FOR DEMOLISHED AGGREGATES. C. Water cement ratio: More the water cement ratio more will be the workability of the concrete. Since by simply adding of water, the inter particle lubrication is increased. High water content results in a higher fluidity and greater workability but reduces the strength of concrete. Because with increasing water cement ratio the strength decreases as more water will result in higher concrete porosity. So, the lower the water cement, the lower is the void volume or solid volume, and the stronger the harden cement paste. For our project we have used 0.7, 0.8, 0.9 water/cement ratio to find the workability of concrete. Use of 0.4,0.5,0.6 water/cement ratio may not flow well enough to be placed. More water is therefore used than is technically necessary to react with cement. For higher strength concrete lower ratios are used, along with a plasticizer to increase flow ability. D. Compressive strength test: A concrete should be strong in compression in order to resist compressive strength. To find the compressive strength of our concrete the following formula was used. Compressive strength = LOAD / AREA Size of test specimen = 10*10*10 cm Table 6: COMPRESSIVE TEST FOR DEMOLISHED AGGREGATE Types of concrete DAYS (N/mm 2 ) Normal concrete % demolished (coarse and fine) 100% demolished 5% demolished 10% demolished 15% demolished 20% demolished 30% demolished Types of concrete W/c Slump (cm) W/c 0.8 W/c 0.9 Avg. Normal concrete % demolished (coarse and fine) 100% demolished 5% demolished 10% demolished 15% demolished 20% demolished 30% demolished EXPERIMENTAL PROCEDURE FOR PLASTIC AGGREGATE A. Introduction The following describes the experimental work. Firstly, the material, mix proportions, mixing, casting and curing of the specimens are explained. This is then followed by 832

5 description of types of specimens used, test procedures and test results. Plastic recycling was taking place on a significant scale in an India. As much as 60 % of both industrial and urban plastic waste is recycled which obtained from various sources. People in India have released plastic wastes on large scale have huge economic value, as a result of this, recycling of waste plastics plays a major role in providing employment. This helps for the economic development of the country. [11] B. Mix Proportion: The mix proportion used for test was 1:2:4. The total replacement of plastic aggregate was not feasible. So partial replacement by 0%, 5%, 10%, 15% and 20% so on is done. [12] C. Mixing, Casting, And Curing: Initially the dry mix of cement, sand and coarse aggregate with 5% replacement of plastic aggregate was done in 95% of normal course aggregate. It was mixed for about 10 min. Water was added to the dry mix and mixed for 4 min to contain a fresh concrete. The slump test was done after mixing. And the fresh concrete was immediately caste into the mould in three layers for cube specimen. The compaction of the specimen, each layer giving 15 strokes by tamping rod was done. Then it was further cured for 3days, 7days, and 28days. 12. TEST PROCEDURES A. General procedure: The mix proportion of 1:2:4 with 12.5 mm coarse aggregate size with water cement ratio varying from 0.7, 0.8, and 0.9 was used. B. Slump test: Types of material Weight in 3 days Normal 2.45 kg Demolished 2.35 kg Plastic 1.9 kg Table 7: RESULTS OF SLUMP TEST C. Compressive strength test: Concrete being weak in tension and strong in compression. A concrete should be strong in compression in order to resist compressive strength. To find the compressive strength of our concrete the following formula was used. Compressive strength = LOAD / AREA Size of test specimen = 10*10*10 cm Table 8: COMPRESSION STRENGTH TEST Types of concrete DAYS (N/mm 2 ) % Plastics % Plastics % Plastics % Plastics COMPARISON OF THE WEIGHT OF CUBES USING DIFFERENT MATERIAL Graph E: Comparison of weight between different cubes. 14. RESULT AND ANALYSIS A. Slump test analysis: Plastics workability: A concrete is said to be workable if the slump height does not exceed 15cm.therefore, the slump of plastic aggregate was decreasing sharply with the increase in plastic ratio. Hence, 10% replacement was found to be workable then 5% replacement. The plastic concrete are suitable for use in precast applications and large sites.. Demolished workability: Demolished, material with 100% coarse aggregate was found to be workable. B. Compressive test analysis: Demolished: The use of demolished aggregate generally increases the drying shrinkage creep and porosity to water decreases the compressive strength of concrete as compared to normal concrete. Plastic: With the increase in the plastic ratio there is a decrease in the compressive strength. C. Durability Analysis Durability of plastic aggregate: Plastic aggregate are impact and wear resistance and can withstand higher temperature. Durability of demolished aggregate: Hence, demolished aggregate can be feasible to replace up to 20% from the durability point. 14. CONCLUSION weight of wet cube weight of wet cube2 weight of wet cube3 The use of plastic aggregates in concrete reduces its self weight by 44%. Water required was increased with the increase in the proportion of demolished aggregate. With the increase in the proportion of the plastic there was gradual decrease in the compressive strength. As far as the consumption of natural aggregates is concerned, the uses of artificial and recycled 833

6 aggregates as a partial replacement of natural ones have to be encouraged to manage the waste from the industries towards a more sustainable development. Therefore, recycling of plastic and the use of demolition materials reduces the demand of new resources. It cuts down the cost of transportation, production and hence, it is very economical. REFERENCE [1] Initial and finial setting time (IS4031 part ) CivilBlog.org [2] 1T.Subramani, V.K.Pugal2 Experimental Study On Plastic Waste As A Coarse Aggregate For Structural Concrete International Journal of Application or Innovation in Engineering & Management (IJAIEM) Volume 4, Issue 5, May 2015 ISSN Sikkim, India as a Lecturer since 2011 till date. [2] Anushiya Pradhan is a final year Diploma student, Dept. Of Civil Engineering from Centre for Computers and Communication Technology, Polytechnic, Chisopani, South Sikkim. [3] Kiran rai is a final year Diploma student, Dept. Of Civil Engineering from Centre for Computers and Communication Technology, Polytechnic, Chisopani, South Sikkim. [3] Shivakumar, M. N1, Nithin K.S2, B.M Gangadharappa3 USE OF BUILDING DEMOLISHED WASTE AS COARSE AGGREGATE IN POROUS CONCRETE IJRET: International Journal of Research in Engineering and Technology eissn: pissn: Volume: 03 Issue: 06 Jun [4 Polyethylene terephthalate- Wikipedia the free encyclopedia _terephthalate [5] P. Suganthy1, Dinesh Chandrasekar2, Sathish Kumar. P. K3 UTILIZATION OF PULVERIZED PLASTIC IN CEMENT CONCRETE AS FINE AGGREGATE IJRET: International Journal of Research in Engineering and Technology ISSN: Volume: 02 Issue: 06 Jun [6] MnDot materials laboratory (materials and soil testing) Manual number [7] Transportation engineering lab manual. [4] Anisha Upadhyaya is a final year Diploma student, Dept. Of Civil Engineering from Centre for Computers and Communication Technology, Polytechnic, Chisopani, South Sikkim. [5] Karuna chettri is a final year Diploma student, Dept. Of Civil Engineering from Centre for Computers and Communication Technology, Polytechnic, Chisopani, South Sikkim. [8] 1T.Subramani, V.K.Pugal2 Experimental Study On Plastic Waste As A Coarse Aggregate For Structural Concrete International Journal of Application or Innovation in Engineering & Management (IJAIEM) Volume 4, Issue 5, May 2015 ISSN [9] Sieve analysis for fine aggregate for the distribution of different grades. [10] How coarse aggregate affects the mix design [11] Pramod S. Patil1, J.R.Mali2, Ganesh V.Tapkire3, H.R.Kumavat4 INNOVATIVE TECHNIQUES OF WASTE PLASTIC USED IN CONCRETE MIXTURE IJRET: International Journal of Research in Engineering and Technology eissn: pissn: Volume: 03 Special Issue: 09 NCETCE-2014 June [12] IS 456: 2000 mix design of concrete. IS 516:1959, methods of test for strength of concrete. BIOGRAPHY [1] Prashika Tamang is presently associated with the Department of Civil Engineering at Centre for Computer and Communication Technology (CCCT-Govt. Polytechnic) Chisopani, South 834