International Journal of Research and Innovation (IJRI)
International Journal of Research and Innovation (IJRI) 1401-1402
CONSTRUCTION WASTE RECYCLING
Mohd Aslam 1, Ketepalli Sravani2, 1 Research Scholar, Department of Civil Engineering, Aurora Scientific Technological and Research Academy, Hyderabad India. 2 Assistant Professor, Department of Civil Engineering, Aurora Scientific Technological and Research Academy, Hyderabad India.
Abstract Indian construction industry is growing at a rate of 9.2% as against the world average of 5.5%. Construction by nature is not an eco-friendly activity. Construction, renovation and demolition activities lead to the formation of waste. Growth in construction activities generates construction waste which is fast becoming a serious environmental problem with deadly consequences. Most of the construction and demolition, waste in our country are not recycled but end up in landfills occupying valuable land. The promotion of environmental management and the mission of sustainable development have exerted the pressure demanding for the adoption of proper methods to protect the environment across all industries including construction. Construction waste recycling reduces the demand up on new resources. Cuts down the cost and effort of transport and production. Use waste which would otherwise be lost to land fill sites. Waste - Material by-product of human and industrial activity that has no residual value. Need for Comprehensive construction waste management in every site. Every personnel from the management to the operational level should work for the goal of construction waste management. Recycled precast elements and cubes after testing (the aggregate could be relatively clean with only cement paste adhering to it). Demolished concrete building (aggregate could be contaminated with bricks and tiles, sand and dust, timber, plastics, cardboard and paper and metals). Used as a subtitle for natural coarse aggregates in concrete.
*Corresponding Author: Mohd Aslam, Research Scholar, Department of Civil Engineering, Aurora Scientific Technological and Research Academy, Hyderabad India.
Published: July 11, 2015 Review Type: peer reviewed Volume: II, Issue : II
Citation: Mohd Aslam , Research Scholar (2015) "CONSTRUCTION WASTE RECYCLING"
INTRODUCTION GENERAL Concrete is an artificial material in which the aggregates are bonded together by the cement when mixed with water. With the advancement of technology and increased field of application of concrete and motors, the strength, workability, durability and other characteristics of the ordinary concrete can be made suitable for any situation. For this, definite proportions of cement, water, fine aggregates, coarse aggregates, mineral admixtures and chemical admixtures are required. INTRODUCTION TO RECYCLED AGGREGATE In recent years certain countries have considered the reutilization of construction and demolition waster as a new construction material as being one of the main objectives with respect to sustainable construction activities. This thesis focuses on recycling of concrete waste as an aggregate in structural concrete. From the mid 70s many
researchers have dedicated their work to describe the properties of these kinds of aggregates, the minimum requirements for their utilization in concrete and the properties of concretes made with recycled aggregates. However, minor attention has been paid to both the structural behaviour of recycled aggregate concretes and their durability. Recycling is the act of processing the used material for use in creating new product. The usage of natural aggregate is getting more and more intense with the advanced development in infrastructure area. In order to reduce the usage of natural aggregate, recycled aggregate can be used as the replacement materials. Recycled aggregate are comprised of crushed, graded in organic particles processed from the materials that have been used in the constructions and demolition debris. These materials are generally from building, roads, bridges and sometimes even from catastrophes, such as wars and earthquakes. SOURCES OF RECYCLED AGGREGATE Traditionally, Portland concrete aggregate from the demolition construction is used for landfill. But nowadays, Portland concrete aggregate can be as a new material for construction usage. According to recycling of Portland cement concrete, recycled aggregate are mainly produced from the crushing of Portland concrete pavement and structures building. It stated that the isolated areas of 1 inch of asphalt concrete could be used to produce the recycled aggregate. The main reason that choosing the structural building as this source for recycled aggregate is because there is a huge amount of crushed demolition Portland cement concrete can be produced.
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International Journal of Research and Innovation (IJRI)
4%) Iron Oxide (3-4%) Magnesia (0.1-3%) Sculpture (13%) and Alkalis (0.3-2%)
Ordinary Portland cement is the basic Portland cement and is the best suited for use in general concrete construction where there is no exposure to sulphates in the soil or in the ground water. This mixture is grounded, blended fused in kiln at high temperature of 1400 Celsius and is the product called clinker is obtained. The clinker is cooled and grounded to get cement. This cement is produced in maximum quantity than the other cements because of its durability and resistance of atmosphere and other attacks. Grinding Portland clinker with the possible addition of small quantity of gypsum, water or both not less than 1% of air entraining elements produces it. AGGREGATES APPLICATIONS OF RECYCLED AGGREGATE Traditionally, the application of recycled aggregate is used as landfill. Nowadays the application of recycled aggregate areas is wide. The applications are different from country to country. CONCRETE KERBS AND GUTTER MIX Recycled aggregate have been used as concrete and gutter mix in Australia. According to building innovation &construction technology (1999), stone says that the 10mm recycled aggregate and blended recycled sand are used for concrete kerb and gutter mix in the lethally street project in Sydney. MATERIALS USED IN CEMENT CONCRETE The quality of concrete can be achieved by the selection of suitable materials, admixtures, the choice of mix proportions, w/c ratio and use of proper methods of placement and curing. All these aspects depend upon material and admixtures selection.
COARSE AGGREGATE The aggregate like sand and brick and stone are inert materials. Their properties greatly influence the behaviour of concrete since they occupy about 80% of the total value of the concrete it is logical to us maximum, of aggregate since they are less expensive than cement and are freely are available in natural. They aggregates are classified as fine aggregate and coarse aggregate and comply with the requirements of IS 383-1970. Fine aggregates are material passing through as IS Sieve that is less than 4.75 mm gauge beyond which, they are known as coarse aggregate. For maximum strength and durability, the aggregate should be packed and cemented as compactly as possible for this reason the gradation of particle sizes in aggregate to produce close packing is of considerable importance. It is necessary that aggregate have good strength, durability and weather resistance, their surface is free from impurities such as loam, silt and organic matter which may weaken the bond with the cement paste and that no unfavourable chemical reaction takes place between them and cement.
CEMENT Cement is a material that has cohesive and adhesive in the properties in the presence of water. Natural cement is obtained by burning and crushing the stones containing clay, carbonate of lime and some amount of carbonate of magnesia. Natural cements resemble very closely hydraulic lime. It sets very quickly after addition of water. It is not strong as artificial cement. The artificial cement was invented by a mansion Joseph Aspidin of England it is therefore, sometimes referred as Portland cement. The two basic ingredients of cement are calcareous and argillaceous products usually containing Lime (62-67%) and Silica (17-25%) Alumna (3-8%) Calcium Sulphate (3146
International Journal of Research and Innovation (IJRI)
FINE AGGREGATE Concrete is a composite material, the workability and the development of strength depend upon the age, the properties of the constituent materials and their combined action. The role of fine aggregate on strength and workability has to be deciphered before examining the possibility of total replacement of fine aggregate. The purpose of mix proportioning is to produce the required properties in both plastic and hardened concrete by the most economical and practical combination of materials available they has been very little used reported of vast quantities of wastes have generated by mixing and quarrying industries only small amount of this waste are used in road making and in manufacture of building materials such as light weight aggregate bricks and autoclaved bricks an attempt is made to study the affect of rock dust as fine aggregate on the strength and workability aspects of concrete mixes.
How fly ash contributes to concrete durability and strength. Most people don’t realize that durability and strength are not synonymous when talking about concrete. Durability is the ability to maintain integrity and strength over time .strength is only a measure of the ability to sustain loads at a given point in time. Two concrete mixes with equal cylinder strength can vary widely in their permeability, resistance to chemical attack, resistance to cracking and general deterioration over time- all of which are important to durability. Cement normally gains the great majority of its strength within of 28days ,thus the reasoning behind specifications normally requiring determination of 28days strengths as a standard. RECRON- 3S FIBRE Recron-3s fibre was used in the present investigation. Recron-3s fibre is a Polyester synthetic fibre, manufactured by Reliance Industries Limited located at Somajiguda; Hyderabad. The recron–3s fibres contribute to crack control, permeability and flexibility. This improves the durability of concrete.
It is evident that the concrete strength development depends upon the strength of the cement mortar and it’s synergetic with coarse aggregate. Pebbles as coarse aggregate, due to smooth surface texture impart lower mortar aggregate bond strength than that imparted by crushed coarse aggregates. In the present work, fine aggregate consisting of natural sand conforming to grading zone II of IS 383 – 1970 is used. ROLE OF FLY ASH IN CEMENT Fly Ash, known also as pulverized fuel ash is the ash precipitated electro statically or mechanically from the exhaust gases of coal fired power stations to generate electric power and is the most common artificial pozzolana. The Fly Ash particles are spherical and its fineness is very high. Fly Ash is available in large quantities in the country as a waste product from a number of thermal power stations and industrial plants using pulverized bituminous/sub-bituminous coal as fuel for the boilers. Fly ash also makes substantial contributions to workability, chemical resistance and the environment. To fully appreciate the benefits of fly ash in concrete must be understood. Concrete is a composite material, which essentially consists of two components: aggregates and cementitious paste.
Key Benefits of Recron-3s i. Plane concrete- Non Homogeneous mix
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International Journal of Research and Innovation (IJRI)
ii. Fortified with Recron-3s-Homogeneous mix
fly ash were spread out on the aggregate and mixed thoroughly in dry state turning the mixtures over and over until uniformity of colour was achieved, as shown in plates. Water was measured exactly by weight and thoroughly mixed to obtain homogeneous concrete. The time of mixing shall be 10-15 minutes.
EXPERIMENTAL PROGRAMME INTRODUCTION This experimental programme describes the manufacture of test specimens, and presents the detail of the test program. The experimental program was designed to complete the mechanical properties i.e., compressive strength and flexural strength of concrete with M25 grade of Recycled and Natural aggregate. Subsequently a part of cement was replaced by fly ash and Recron-3S fibres that cause the variations in strength were studied. 3.2 STUDY OF MATERIALS The material that are used for the current experimental are • Cement • Fine Aggregate • Natural Coarse Aggregate • Recycled Coarse Aggregate • Water • Recron-3s Fibre • Fly Ash
PLACING OF CUBES
SEQUENCE OF OPERATION
mould oil and a similar coating of mould oil was applied between the contact surfaces of the bottom of the moulds and the base plate in order to ensure that no water escapes during the filling. The interior surfaces of the assembled moulds were thinly coated with mould oil to prevent adhesion of the concrete and for easy removal of moulds after casting. Then the moulds are arranged on the vibrator platform for casting. The mix was placed in three layers. Each layer was compacted using table vibrator to dense concrete.
The Investigation was carried on M40 grade concrete. The mix design has done according to IS: 10262-2009 code method. Required quantities of material are calculated. Cement, sand, coarse aggregate and fly ash is thoroughly mixed in dry state manually so as to obtain uniform colour. Then the required percentage of additive (Recron-3S) is added to the water calculated for that particular mix. This water is added to the dry mix with a view to obtain uniform mix. The compaction factor test and slump cone test were carried out and the respective values were recorded for all mixes. The cube moulds were kept on table vibrator and the concrete was poured into the moulds in 3 layers by poking with a tamping rod and vibrated by table vibrator. In the beam moulds concrete was poured in 3 layers by poking with tamping rod and needlle vibrator was used in order to get good compaction. CASTING AND CURING OF TEST SPECIMENS
The cube moulds and beam moulds are cleaned and all care was taken to avoid any irregular dimensions. The joints between the sections of moulds were coated with
CURING The test specimens cubes and beams were stored in place from vibration in moist air at 90% relative humidity. After 24 hours the specimens were demoulded and immediately immersed in clean, fresh water tank for a period of 28days. Curing of Beams were done by placing mats on them and watering was done in regular intervals keeping in view that no loss of moisture content from the beams is lost
The specimens of standard cubes (150mmx150mmx150mm) thirty in numbers were caste and standard beam (1500mmx150mmx230mm) ten in numbers were caste. Cement was replaced by fly ash by 25% by weight of cement and they were caste. MIXING Measured quantities of coarse aggregate and fine aggregate were spread out over an impervious concrete floor. The dry ordinary Portland cement (coromandel king) and 148
International Journal of Research and Innovation (IJRI)
TESTING PROCEDURE
TEST FOR COMPRESSIVE STRENGTH OF CONCRETE
TESTS FOR WORKABILITY
On the date of testing i.e., after 28days casting of the cubes specimens were removed from the water tank and placed on flat surface for 10 minutes to wipe off the surface water and grit, and also removes the projecting fines on the surface of the specimens. Before placing the specimen in the testing machine the bearing surface of the testing machine was wiped clean and the cube specimen also cleaned. The cube specimen was placed in the machine, of 2000KN.
SLUMP CONE TEST Slump cone test is a very common test for determination of workability of concrete. This test was carried out for both cubes and beams before casting the specimens. The slump was measured in (mm) as shown in plate, also the slump values are presented
COMPACTION FACTOR TEST This test is more accurate than slump cone teat and this test is used to determine the workability of low water cement ratio concrete, more accurately. The compaction factor values are obtained by this test are presented.
TEST RESULTS AND DISCUSSIONS GENERAL Series of tests were carried out on the concrete specimens to obtain the strength characteristics of fiber concrete beams for different percentages of recycled and natural aggregate. This chapter discusses on the results that obtained from the testing. The results such as workability, Compressive test, Deflection pattern of beams and Crack pattern compared to that of the conventional beams are discussed and tabulated PHYSICAL PROPERTIES In this study, the following tests were conducted to note the physical properties of the materials i.e., specific gravity, water absorption and fineness modulus.
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International Journal of Research and Innovation (IJRI)
showing the compation factor vs fibre content
SPECIFIC GRAVITY The specific gravity of the fine aggregate was 2.63 and coarse aggregate natural was 2.74 and recycled was 2.62 respectively. WATER ABSORPTION The water absorption of the fine aggregate was 1.0% and coarse aggregate natural was 0.826% and recycled was 28.6% respectively. FINENESS MODULUS The fineness modulus of the fine aggregate was 3.57 and coarse aggregate natural was 7.454 and recycled was 7.535 respectively. PHYSICAL PROPERTIES OF AGGREGATE SI.NO
Property
Fine Aggregate 2.55
Natural Coarse Aggregate
Recycled Coarse Aggregate
2.7
2.71
1
Specific gravity
2
Fineness modulus
3.57
7.454
7.535
3
Water absorption
1.0%
0.826%
3.67%
4
Bulk density
1.80 kg/lt 1498kg/m3 1710kg/m3
1492kg/m3 1712kg/m3
a)loose b)compacted
SLUMP AND COMPACTION FACTOR OF NATURAL AGGREGATE CONCRETE
SL.NO
MIX
FIBRE (%)
SLUMP(MM)
COMPACTION FACTOR
1.
M25
0
80
0.86
COMPRESSIVE STRENGTH OF NATURAL AGGREGATE CONCRETE S.NO
MIX
COMPRESSIVE STRENGTH(MPA)
FIBRE (gm/ cu.m)
1.
M25
30.00
0
COMPRESSIVE STRENGTH OF RECYCLED AGGREGATE CONCRETE S.NO
MIX
COMPRESSIVE STRENGTH(MPA)
FIBRE (gm/ cu.m)
1.
M25
21.67
0
COMPRESSIVE STRENGTH OF RECYCLED AGGREGATE CONCRETE BY ADDING FIBRES S.NO
MIX
COMPRESSIVE STRENGTH(MPA)
FIBRE (gm/ cu.m)
1.
M25
28.33
900
showing the compressive strength vs fibre content
SLUMP AND COMPACTION FACTOR OF RECYCLED AGGREGATE CONCRETE
SL.NO
MIX
FIBRE (gm/ cu. m)
SLUMP(MM)
COMPACTION FACTOR
1.
M25
900
60
0.88
Showing the slump vs fibre content
BEAM DEFLECTION(A) The load versus mid-span deflection curve of the test beams of natural aggregate without fiber
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International Journal of Research and Innovation (IJRI)
MOMENT CURVATURE(A)
recycled aggregate with 0.50% of fibre
The moment versus curvature curve of the test beams of natural aggregate without fibre.
CONCLUSION BEAM DEFLECTION(B) The load versus mid-span deflection curve of the test beams of recycled aggregate with 0.25% of fiber
In order to reduce the construction waste, during the time of construction order only the correct amount of raw materials. Proper care should be taken to ensure the protection of materials being delivered and stored in the site. When a structure is being demolished, salvage as much of the more valuable fittings and materials as possible. Any suitable substitute for aggregate should be considered during the construction. It is the duty of an engineer to revaluvate technical specification for materials where strength and safety do not have to be compromised to permit the use of recycled materials. As sorting and recycling facilities become more wide spread and better developed it will be easier to redirect our waste from landfill. By using recycled coarse aggregate cost of construction gets reduced and even gives better strength than natural coarse aggregate when it is mixed with Fibres and Fly Ash. This should be more implemented in the future so as to decrease the waste generated for buildings, etc.
MOMENT CURVATURE (B)
REFERENCES
The moment versus curvature curve of the test beams of recycled aggregate with 0.25% of fiber
1. Concrete Technology by M.S.Shetty, S.Chand Publications. 2. L.Y.Shen, D Drew, and C.M. Tam, (2004), Construction Waste recycling, Journal of Construction Engineering and Management,4,Vol 130,pp 472-481. 3. Jessica Krippendor(2008), Construction Waste recycling Journal of Canadian wall and ceiling,pp14-18. 4. Darin Steen(2008),Bios Force builds low cost C&D Landfill, Journal of Tribal Waste. pp 8-10. 5. Journal on Fibre Reinforced Concrete by N. Banthia
AUTHOR
BEAM DEFLECTION(C) The load versus mid-span deflection curve of the test beams of recycled aggregate with 0.50% of fiber
MOMENT CURVATURE(C) The moment versus curvature curve of the test beams of
Mohd Aslam , Research Scholar, Department of Civil Engineering, Aurora Scientific Technological and Research Academy, Hyderabad India.
Ketepalli Sravani, Assistant Professor, Department of Civil Engineering, Aurora Scientific Technological and Research Academy, Hyderabad India.
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