Fibred paving block

FIBERED PAVING BLOCK1. INTRODUCTIONBook 4 Segmented concrete paving is a system of individual shaped blocks arranged to form a continuous hardwearing surface overlay. Over the past two decades, paving composed of segmental blocks has become a feature of our towns and cities. It is to be found in commercial industrial and residential areas, in the paving malls, plazas, parking areas and bus stops. It has been successfully used for embankment walls, slope protection and erosion control. During this period, extensive research has been carried out on the engineering characteristics and structural performance of segmental block paving. Existing pavements subjected to heavy bus traffic and industrial loads have been monitored and their service life shown to be satisfactory. The India Bureau of Standards has published specifications relating to the quality of concrete paving blocks and required standards of construction. The Committee of Urban Transport Authorities has published a catalogue of designs for segmental block pavements. The engineering and specification aspects have been satisfactorily solved, and this type of paving has a proven performance and service record. But the aesthetic use of segmented paving and the contribution it can make to improve our urban landscape is only now being appreciated.

Roman road built 2000 years ago using segmented paving.HISTORY

Although pavers made out of concrete may be a new product, the use of paving blocks as a surfacing material is anything but new. The first record of stone paving dates back to 4000 BC in Assyria and by 2000 BC, flagstones were being used to pave village streets. Cobblestones were the traditional method of stone paving, being uncut and often water-worn stones or large pebbles about 150mm in size. Later hand-cut stone blocks were introduced. Road-making using brick was common in Mesopotamia n 2000 BC and clay brick paving was in use in India in 300 BC. It was the Romans who introduced hexagonal-shaped flagstones as a surface course, so the concept of shaped, rather than rectangular blocks, is certainly not new. Perhaps the most famous of all Roman roads is the Appian Way, built by Roman engineers in 312 BC. The 377 kilometer road was surfaced with tight fitting paving stones that still carries traffic between Rome and Italys south eastern port of Brindisi. Concrete paving blocks were first manufactured in the Netherlands in 1924. It was probably World War II that led to the growth of concrete blocks as a paving material. Large areas of the Netherlands were destroyed during the War and, because clay bricks were in short supply (and what was available was being used to rebuild housing), concrete blocks were introduced as an alternative. Subsequently, concrete block paving (cbp) became recognized as a paving material in its own right. The research carried out by Shackel in the late 70s and early 80s remains the most comprehensive yet conducted into the performance of concrete block paving. A hierarchy of block shapes was developed, the existing design curves were examined, the role of the bedding and jointing sands was investigated in earnest, and various base and sub-base materials were tested.

APPLICATIONS OF PAVING BLOCK PAVINGCK PAVING Concrete pavers are a versatile paving material, which due to the availability of many shapes, sizes and colures, has endless streetscape design possibilities. The use of concrete block paving can be divided into the following categories.

ROADS

Main roads Residential roads Urban renewal Intersections Toll plazas Pedestrian crossings Taxi ranks Steep slopes Pavements (sidewalks)

COMMERCIAL PROJECTS

Car parks Shopping centers and malls Parks and recreation centers Golf courses and country clubs Zoos Office parks Service stations Bus termini Indoor areas Places of worship

INDUSTRIAL AREAS

Factories and warehouses Container depots Military applications Mines Wastewater reduction works Quarries Airports and harbors

DOMESTIC PAVING

Pool surrounds Driveways Patios Townhouses and cluster homes SPECIALIZED APPLICATIONS

Cladding vertical surfaces Storm water channels Embankment protection under freeways Roof decks

ROADS:

The change in texture of the road surface at intersections produces an audible change in road noise, thereby alerting drivers to the fact that they are approaching the intersection. The surface characteristics of the blocks offer a greater resistance to skidding in wet weather, largely due to the chamfered joints of the blocks and the rapid dissipation of surface water. Should remedial work be necessary, e.g. on underground services, blocks can be removed and replaced without impairing the overall appearance of the road pavement. The use of red blocks on roads at the approaches to the intersection produces a distinct visual difference, thereby promoting care and awareness among drivers.

Major road construction using concrete block paving. A technically excellent surfacing, which also provides community upliftment in the from the job creation during the construction.

At pedestrian crossings, a designer can place a different texture or colour from that of the street or parking area. This distinguishes pedestrian areas from vehicular areas, providing a safe haven for the pedestrian, especially those with physical handicaps.

COMMERCIAL PROJECTS

Car parks are typically exposed to the full rigours of sun and rain. Unlike asphalt surfaces, concrete block paving shows little weathering or deterioration under these circumstances and yields low maintenance costs. An imaginative designer can overcome the drab monotony too often characteristic of parking lots, by exploiting the wide range of colours and textures provided by concrete pavers. Another advantage of concrete block paving is the maintenance-free Demarcation of parking areas. Concrete block paving provides an attractive hard-wearing surface for parks. It blends with the environment and breaks up the harshness of conventional hard Landscaping.

INDUSTRIAL AREAS

At factories and warehouses concrete block paving has the ability to withstand concentrated heavy loads and to resist the wheel loads of off-road vehicles such as cranes and forklifts.

At factories and warehouses, concrete block paving has the ability to withstand concentrated heavy loads and resist the wheel loads of off-road vehicle such as cranes and forklifts.

DOMESTIC PAVING

Concrete block paving provides functional yet very attractive pool surrounds.

Concrete block paving blends in with the landscape and increases the attractiveness and value of townhouses and cluster homes.

SPECIALISED APPLICATIONS

Embankment protection alongside freeways. The use of concrete block paving is a very effective and quick method of slope protection

Century City roof deck with a good detail across the expansion joint.

PATTERNS IN CONCRETE PAVING BLOCKS - Concrete block pavers come in a variety of shapes and sizes . If we consider for a moment the aesthetics of concrete block paving, three fundamental aspects present themselves: Shapes Colours Patterns Applying just a few variables to each aspect presents a myriad of options from which even the most discerning client may happily choose.

SHAPES

Aristocrat Satinpave

Conleaf Classic Cobble

Clover Tiffany Honeystyle

Corolock, Double zig zag Corolink

COMPARISON OF CONCRETE PAVING BLOCKS WITH OTHER TYPE OF PAVEMENT In certain specific areas of application, block paving, with its cost-effectiveness, aesthetic qualities, ease of construction and maintenance and in-service advantages, is the paving of choice. In Table 2, a comparison with conventional flexible and rigid pavements, based on these attributes is given. In general, it can be said that concrete block paving excels in terms of cost and performance in the following circumstances: Where heavy or concentrated wheel loads are to be carried and especially where a high frequency of turning or slewing movements is expected. Where volume of traffic is high. Where sub-grade conditions are poor. Where the pavement must withstand severe in-service conditions such as considerable temperature variations, frequent fuel, oil or lubricant spillage or extensive, significant and substained settlement. Where ready access to underground services is required. Where the appearance and aesthetic qualities of the pavement are major design considerations.

ADVANTAGES OF PEVING BLOCKS High abrasion and skid resistance. No damage from petroleum products. No damage from concentrated point loads or high Temperatures. No damage by soap or detergents

REQUIREMENTS FOR CONCRETE PAVING BLOCKS

Properties : Blocks should meet structural requirements for paving specified in terms of block compressive strength and /or tensile splitting strength). Blocks should be durable: they should be able to withstand abrasion , impact and chemical attack . Blocks should be of uniform dimensions to facilitate correct and easy placing and ensure good readability .

THE MANUFACTURE OF CONCRETE PAVING BLOCKS :

Tests have shown that 25 MPa blocks are structurally adequate. Experience indicates however that strength levels should be increased to ensure a higher probability of durability. Block thickness is specified according to traffic and IS 1200 MJ specifies standard thicknesses of 50, 60, 80, 100 and 120mm. It is rarely economical to manufacture the last two sizes. Also in some geographical locations pavers that absorb too much water turn very dark.

2. SELECTION OF MATERIALS

cement : The strength class should be 43,53 garde or higher because blocks are required to develop good strength relatively quickly to permit early delivery without excessive breakages. Aggregate

general:

Natural aggregates used in the manufacture of concrete paving blocks should meet the requirements for aggregates for concrete given in IS Aggregates from natural sources Aggregates for concrete. Slag aggregates may also be used if they can be shown to be physically and chemically sound. Waste materials, or materials not in demand, are often sought after as these are generally relatively cheap. But the use of such materials could be at the expense of quality or result in increased costs due to the need to use higher cement contents to maintain quality. These materials might also create compaction difficulties which could adversely affect productivity and durability. The performance of aggregates at the moulding stage and in the hardened block depends on the combined effects of particlesize, grading, particle shape, and hardness.

size :

The recommended maximum nominal size of aggregate is 13,2 mm. However, the maximum size generally used is 9,5 mm. Smaller sizes may be used to suit circumstances or may be specifically selected to obtain a particular surface texture. Generally, the use of coarse particles results in savings in binder provided the mix is properly proportioned if coarse aggregate particles are too big, or if too much coarse aggregate is used in the mix, it may be difficult to achieve good compaction and acceptable surface texture.

Pigments:

Quality pigments are commercially available to add colour to paving blocks. Dosage, which will depend on the colour selected and the natural colour of the aggregate and cement being used, is generally 5%, but not more than 10%, by mass of the cement. Experimentation may be required to determine the correct dosage because the colour of the finished product in a dry state is influenced by density, curing and surface texture.

DUST : In quarrying and construction, wasted material means wasted profit. Crusher dust is a completely natural byproduct of various mining operations that helps manufacturers increase profits. Some companies spend more time refining their crusher dust than others, and the rougher versions of the dust are sometimes known as manufactured

Description In appearance, crusher dust has a grayish or brownish tone with very fine aggregate particles, like a soft sand. These particles, when looked at under a microscope, are rough cubes and individually have a rough surface texture.Uses Crusher dust is used primarily as filler and cement aggregate. Construction contracts use the sand to weigh down objects or fill in cracks in patios or other stone creations. When used in concrete, the crusher dust mixes in with larger aggregate to help form a specific texture. The dust is also used to make mortar and other similar materials.Benefits Crusher dust has many of the useful properties of the stone that it comes from. It is very heat resistant and contains no plastic chemicals that may be toxic to the surrounding environment over time. The chemical nature of crusher dust is very dependable and largely alkaline which helps manufacturers use it confidently in a variety of materials. It is also durable, strong, and can be easily compressed into tight spaces.

JUTE FIBRE :

Jute, as a natural fibre, has inherent advantages like silky luster, high tensile strength low extensibility, considerable heat and fire resistance and long staple lengths. Jute can be used in many different areas, and has been receiving increasing attention from industry. Their interests focus not only on the traditional uses of jute, but also on the production of other value-added products such as, pulp and geo-texture, composite etc.

Jute fiber is being dehydrated after retting alongside a road

Jute Rope

LIME:

Lime has been used as a primary ingredient in masonry mortars for centuries, and this important use continues to the present day in both historic and contemporary applications. Mortars made with lime and cement exhibit superior workability balanced with appropriate compressive strength, as well as low water permeability and superior bond strength. Lime is a major constituent in exterior and interior stuccos and plasters, enhancing the strength, durability, and workability of these finishes. All of these lime applications are supported by IS specifications and standards.

CHEMICAL ADMIXTURE:

Concrete paving blocks are manufactured from semi-dry mixtures which possess poor flow properties even under vibration. Using a water reducing or plasticizing admixture to improve compatibility may be cost effective.

3. MANUFACTURING EQUIPMENT

Batching equipments: To ensure that a uniform product is obtained, weigh-batching is recommended. For smaller projects, whole bags of cement should be used if the sizes of batch and mixer are compatible. Mixer : Because a semi-dry mixture is used to mould concrete paving blocks, effective mixing can be done with pan and trough mixers. Drum-type mixers are unsuitable. The size of the pan mixer must be related to production so that batches are used up within a reasonable time, i.e. before workability is reduced by moisture loss or hydration of the cement.Moulding machine: Unlike bricks and blocks used for masonry, paving blocks must be dense (fullest possible compaction to be achieved). Equipment must be capable of a high degree of compaction and satisfactory output. A combination of vibration and pressure is the most effective way of achieving compaction. Moulding pressure should be 10 MPa or more. Stationary plants using the pallet system are almost exclusively used as they are capable of providing the necessary high levels of vibration and pressure. Hand machines and egg-layers are unlikely to produce a satisfactory product unless cement is used.

Curing chamber : Newly moulded blocks should be subjected to some form of curing. The form of curing ranges from the prevention of moisture loss to the use of elevated temperature and high humidity, e.g. steam curing. Sieve size Cumulative mm percentage passing : 13, 2 - 100 9.5 , 90-100 4.75 , 70-85 2.36 , 50-65 0.30 ,10-25 0.15 , 5- 15 Fineness modules 3.2 , 4.2

4.MANUFACTURING PROCESS

Batching: The different aggregate types should be stored separately and in such a way that they are well drained. The cement except when batched by whole bags, should be weighed to an accuracy of 1%. Aggregates should be weighed to an accuracy of 2%. It is essential to make allowance for moisture contained in the aggregate wt. by aggregate batching.

Mixing

After batching, the aggregates and binder are discharged separately or simultaneously, together with pigment if required, into the mixer and thoroughly mixed before any additional water is added. Mixes having high fines contents may requirelonger mixing. Based on measurement of the variable moisture content of the aggregates or visual assessment by experienced personnel, water is added to the mixture. Uniformity is important because differences in water content from batch to batch will result in differences in quality. After mixing, the mixture (and topping mix if required) is stored in hoppers ready for dispensing into the moulds.

Filling of moulds:

Most production machines operate on one of two basic principles. In the first and more widely used system, an amount of mixture is progressively compacted under vibration until a predetermined height has been reached. In the second system, a gauged quantity of mixture is compacted for a set period. In both cases, variations in density will result if the gauged quantities are not consistent or the mixture is not uniformly distributed within the mould. These variations are over and above those due to variations in moisture content. Filling isusually facilitated by a period of previbration after which themoulds are topped up with a second filling of mixture. Thermal curingNewly moulded paving blocks are placed in an insulated chamber for a period of 24 hours. Temperature is increased by the heat of hydration of the cement and no additional heat is provided. The method is therefore inexpensive. A constant temperature of 35C or more can be maintained with this system. A high humidity is provided from moisture within the units and good curing can be achieved. After initial curing by one of the methods described above, the pavers are sufficiently hard for stacking, packaging, etc. Shrink-wrapping helps retain moisture for extended hydration but might promote lime bloom. Compaction:

The optimum period of vibration must be determined experimentally in the plant but is usually 3 to 12 seconds. Good compaction is more difficult to achieve in thicker blocks and those that have acute angles. For this reason concrete pavers with a thickness greater than 80 mm are seldom manufactured. Frequency and amplitude of vibration should be optimized for the specific materials being used and the number of blocks being moulded per cycle .

Curing : As with all concrete products, the quality of concrete pavers is improved by water curing. However, it is not practicable to apply significant amounts of water onto newly moulded pavers or subsequently to subject them to water sprays or immersion in water. The phenomenon of efflorescence further complicates curing in practice. Here the calcium hydroxide combines with carbon dioxide from the atmosphere to form less soluble calcium carbonate which is white in colour. Known as lime bloom, it is particularly noticeable on coloured pavers. Other than for aesthetic reasons, lime bloom is not a problem and will disappear with time by normal weathering and the action of rainwater which is mildly acidic.

Quality control : Control measures should be implemented to : a) Monitor changes in materials so that timely changes can be implemented in manufacture. b) Routinely monitor the quality of the product for compliance with the specification. Measure under category : a) includec) Regularly monitor changes in grading and moisture content of aggregate.d) Monitor mix consistence e) Measure wet density of blocks (by weighing). Causes for a change in density must be investigated. The more routine quality/compliance test under category b) include: f) Check on dimensions of blocks . g) Test strength of blocks . h) Carry out abrasion tests at an appropriate a

5.TESTING

UTM MACHINE:

6. RESULT

SR.NOTYPES OF BLOCKSSYMBOLLOAD (KN)

3 DAY7 DAY28 DAY

1.NormalN1237.18357.020371.380

N2160.94347.480369.270

N3153.84356.820360.650

2.Cement + FibreCF1303.9400.000391.980

CF2272.48400.180400.080

CF3280.88349.800400.700

3.Lime + FibreLF1161.34244.380222.600

LF2166.88241.660225.870

LF3183.33210.800229.230

4.Cement + Lime + FibreCLF1243.08324.620395.760

CLF2220.58318.560399.080

CLF3197.88322.280400.910

Sr. NoTypes Of BlocksAverage load (KN)

3 Days7 Days28 Days

1Normal183.980353.770367.100

2Cement + Fibre285.750383.320397.586

3Lime + Fibre170.510332.280225.900

4Cement + Lime + Fibre220.510321.820398.583

Sr.noTYPES OF BLOCKSSYMBOLWEIGHT (Kg.)

3 DAY7 DAY28DAY

1.NormalN13.5063.3223.525

N23.4043.4083.517

N33.4213.3183.536

2.Cement + FibreCF13.0533.3313.325

CF23.2323.1463.219

CF33.1363.2753.408

3.Lime + FibreLF12.9772.9522.856

LF23.1532.8753.120

LF33.2263.0352.994

4.Cement + Lime + FibreCLF13.3293.1483.129

CLF23.0913.2592.948

CLF33.2073.1953.163

Sr. NoTypes Of BlocksAverage weight (Kg.)

3 Days7 Days28 Days

1Normal3.4433.3493.526

2Cement + Fibre3.1403.2503.317

3Lime + Fibre3.1182.9542.990

4Cement + Lime + Fibre3.2093.2043.080

SR.NOTYPES OF BLOCKSSYMBOLCOMP.STRENGTH (N/mm2)

3 day7 day28 day

1NormalN110.7816.2223.20

N27.3115.7922.55

N36.9916.2123.14

2Cement + fibreCf113.8118.1825.90

Cf212.3818.1925.95

Cf312.7615.9022.69

3Lime + fibreLf17.3314.7515.82

Lf27.5814.4815.65

Lf38.3314.6413.63

4Cement+fibre+limeClf111.0411.1021.77

Clf210.0210.9820.60

Clf38.9910.9820.99

Sr. NoTypes Of BlocksAverage weight (Kg.)

3 Days7 Days28 Days

1Normal8.3616.0722.95

2Cement + Fibre12.9817.4224.87

3Lime + Fibre7.7414.6215.07

4Cement + Lime + Fibre10.0110.5520.88

COMPRESIVE STRENGTH CHART

WEIGHT CHART

RATE ANALYSISSR. NO.TYPES OF BLOCKS RATE PER BLOCK

1NORMAL9.48 Rupees

2CEMENT + FIBRE9.48 Rupees

3LIME + FIBRE9.15 Rupees

4CEMENT + LIME + FIBRE9.31 Rupees

7. CONCLUSION

The every type of jute fibre has been tried out in cement and concrete , not all of them can be effectively and economically used. From above discussion it is clear that the fibred paving blocks are economical in cost & give high strength than normal regular paving blocks.

First type of paving block is cement + fibre paving block. It is same in cost as regular paving blocks & give more strength than regular paving blocks. These blocks are used for high strength work. Likes construction of road work, air ports etc.

The Second type of paving block is cement + lime + fibre. These paving blocks are cheap in cost & give same strength of normal paving block. This blocks are used in parking, footpath construction etc. And Third type of paving block is lime + fibre. This type of paving blocks are very cheap in cost but does not give good strength as compare to regular paving blocks this blocks are used for low strength construction work .likes gardens, parking, footpath, verandah etc .

8.REFRANCES

WEBSITES:

www.cma.org.za www.jutefibre.co www.pvb.co.in

APPENDIX 1Mix Proportion per block NORMAL1) Cement-330gm.2) Fly ash-570gm.3) Dust-830gm.4) Grit-730gm. CEMENT+FIBRE1) Cement-330gm.2) Fly ash-570gm.3) Dust-830gm.4) Grit-730gm.5) Fibre-1gm. CEMENT+LIME+FIBRE1) Cement-165gm.2) Fly ash-570gm.3) Dust-830gm.4) Grit-730gm.5) Fibre-1gm.6) Lime-165gm. LIME+FIBRE1) Fly ash-570gm.2) Dust-830gm.3) Grit-730gm.4) Fibre-1gm.5) Lime-165gm.

APPENDIX 2

Rates (per material)1. Cement - Rs.0.992. Fly ash - Rs.2.013. Dust - Rs.3.124. Grit - Rs.2.375. Fibre - Raw material6. Lime - 0.82

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