Types of road material and its tests
- 1. Types of road materials and Tests DIPLOMA IN CIVIL ENGINEERING AKASH KUMAR -1411518002
- 2. 1.SOIL 2.AGGREGATE 3.BITUMEN 4.CEMENT TYPES OF TEST ON ROAD MATERIAL 1.Test on soil sub grade- C.B.R. Test. 2.Test on Aggregate – Los Angeles abrasion, impact test, shape test. 3.Tests on bitumen- Penetration, Ductility and Softening point test. 4. Test on cement concrete- Workability Tests, Air content test, Setting Time.
- 3. SOIL • In the structure of highway, embankment and subgrade are to be constructed with soil. • The soil is considered as one of the principal highway materials • Soils are mainly of mineral matter formed by the disintegration of rocks, by the action of water, frost, temperature and pressure.
- 4. BASIC CHARACTERISTICS OF SOIL •Soil are based on individual grain size, gravel, sand, silt, and clay • The characteristics of soil grains depend upon the size, shape, texture, chemical composition and electrical charges on the surface of fine soil particles. • Moisture and dry density influence the engineering behavior of soil mass
- 5. DESIRABLE PROPERTIES If a soil is to be used as highway material, it should possess the following properties: 1. Stability 2. Incompressibility 3. Permanency of strength 4. Minimum changes in volume and stability 5. Good drainage 6. Ease of compaction
- 6. FUNCTION OF OF SOIL AS HIGHWAY MATERIAL I. To act as integral part of road pavement. II.To provide stability and durability of road. III.To provide adequate support to the road. IV.To provide proper drainage to the rain water.
- 7. CBR TEST • The California Bearing Ratio (CBR) test was developed by the California state highway department to evaluate the strength of subgrade soil, stone aggregates and other pavement materials • The CBR test method also standardized by BIS. • CBR test results cannot be related accurately with any fundamental property of soil or pavement material.
- 8. Principle: The basic principle is by causing penetration with a cylindrical plunger of 50mm diameter into the specimen of soil/ pavement material at a rate of 1.25mm per minute. CBR TEST (CONTD.) • The loads required for 2.5mm and 5.0mm penetration of the plunger into the soil tested are recorded. • The CBR value of the material tested is expressed as a percentage of standard load value in a standard material. • The standard values given below may directly be used to compute the CBR value of the test material.
- 9. Penetration (mm) Standard load (kg) Unit standard load (kg/cm2) 2.5 1370 70 5.0 2055 105 CBR METHOD -LABORATORY EQUIPMENT MODEL
- 11. APPARATUS • Mould of 150mm diameter, with a base plate and collar • A loading frame with a cylindrical plunger of 50mm diameter • Dial gauge to read deformation • Proving ring attachment CBR TEST PROCESS • The specimen in the mould is compacted to maximum dry density at the optimum moisture content. After subjecting the specimen for soaking of four days, the swelling and water absorption values are noted. • The values are noted corresponding to penetration values of 0.0, 0.5, 1.0, 1.5, 2.0, 2.5, 3.0, 4.0, 5.0, 7.5, 10.0 and 12.5mm.
- 12. 𝑙𝑜𝑎𝑑 𝑎𝑡 2.5 𝑜𝑟 5.00𝑚𝑚 𝑝𝑒𝑛𝑒𝑡𝑟𝑎tion 𝑋 100 𝑠𝑡𝑎𝑛𝑑𝑎𝑟𝑑 𝑙𝑜𝑎𝑑 𝑎𝑡 𝑐𝑜𝑟𝑟𝑒𝑠𝑝𝑜𝑛𝑑𝑖𝑛𝑔 𝑝𝑒𝑛𝑒𝑡𝑟𝑎𝑡𝑖𝑜𝑛 CBR (%) = • CBR test is an arbitrary strength test, hence cannot be used to evaluate the soil properties like cohesion, angle of internal friction or shear resistance • Presence of coarse grained particles would result in poor reproducibility of CBR results. Material passing 20mm sieve is only used in the test. https://youtu.be/fCmMW73rP64
- 14. AGGREGATE Aggregate is a collective term for the miniral material such as sand, gravel, and crushed stone that are used with a binding medium (such as water, bitumen, Portland cement, lime, etc.) to form compound materials (such as bituminous concrete and Portland cement concrete). It is the major component of contruction material which is used in highway. It have ability to bear the stress occuring on the road and also resist the load. It is used in granular bases and sub-bases, bituminous construction and in ciment concrete.
- 15. Types of road aggregate Crushed stone aggregate- This type road aggregate is obtained by crushing of stones by using jaw and roller crusher to the required size. Common stones used for aggregate as basalt, granites, limestones etc. Gravel- These are the rounded and smooth pebbles or rock fragments above 2mm size. Gravel or harder rocks of 5 to 10cm in dimeter are use for road aggregates. For e.g. Streambed gravels, glacial gravel, beach gravel.
- 16. SAND- It is natural material which is gain from the wheathring of sand stone. It consists of angural, irregural or rounded losses grain of silica fassing 10mm IS sieve, It may be natural sand or artificial sand e.g. River sand, sea sand, nala sand. SALAG- It consists of a number of alumino silicates of calcium and magnesium minerals that are formed in some basic igneous rocks. It is usually obtained as a byproduct from blast furnace and it is use as road aggregate.
- 17. LOS ANGELES ABRASION TEST This is very popural test for measuring the abraision resistance of aggregate. The top layers of a pavement get abraded due to the movements of tyres. A material which is very abrasion resistant, has a long life. The test has been standerdized in India (IS-2386-PART-4)
- 18. The machine consists of a circular drum of internal diameter 700mm and length 500mm mounted on a horizonta axis enabling it to be rotated. An abrasive charge consisting of cast iron spherical balls of 48mm dial and weight 390 to 450gm is placed in the cylender along with aggregates. The weight and no. Abrasive sphere varries a/c to the grading of sample. Fig. 4.4 shows los angeles abrasion testing machine. The quantity of aggregate to be used depends upon the gradation and is 5 to 10kg. The cylender is rotated @ of 30-33km/h for 500-1000 revolutions(depend upon the material) After the specified revolutions, the material passing through 1.7mm size sieve is separated. The weight of this material expressed as percentage of the total weight of the sample is known as the los angeles abrasion value.
- 19. PROCEDURE – Aggregate sample weighing 5kg or 10kg depending on the grading is put in the machine along with the abrasive charge. The machine is rotated at a speed of 33r.p.m. for the specific number of revolutions 500 or 1000 depending on the grading of aggregate. Now the sample is taken out of the machine and sieve through 1.7mm sieve and the weight of aggregate passing through 1.7mm seieve is determined. Let this weight be W2 kg.
- 20. Where W1 is the weight of sample put in the machine. •For cement concrete construction, abrasion value should not be more than 16 percent •For bituminous mixes, Los angeles abrasion value for surface courses may be allowed upto 30 percent and •For base courses, this value allowed upto 50% and this test is more dependable than the other test.
- 21. IMPACT VALUE OF AGGREGATE The aggregate impact value gives a relative measure of the resistance of an aggregate to sudden shock or impact, which in some aggregates differs from its resistance to a slow compressive load. Objective To determine the aggregate impact value in highways against motion of vehicle. Apparatus Required 1. weighing machine
- 22. 2: Sieves 3: Impact Testing machine
- 23. Procedure 1. The test sample shall consist of aggregate the whole of which passes a 12.5 mm IS Sieve and is retained on a 10 mm IS Sieve. The aggregate comprising the test sample shall be dried in an oven for a period of four hours at a temperature of 100 to 110°C and cooled. 2. The measure shall be filled about one-third full with the aggregate and tamped with 25 strokes of the rounded end of the tamping rod. Further similar quantity of aggregate shall be added and a further tamping of 25 strokes given. The measure shall finally be filled to overflowing, tamped 25 times and the surplus aggregate struck off, using the tamping rod as a straight edge. The net weight of aggregate in the measure shall be determined to the nearest gram (Weight A).
- 24. 3. The impact machine shall rest without wedging or packing upon the level plate, block or floor, so that it is rigid and the hammer guide columns are vertical. 4. The cup shall be fixed firmly in position on the base of the machine and the whole of the test sample placed in it and compacted by a single tamping of 25 strokes of the tamping rod. 5. The hammer shall be raised until its lower face is 380mm above the upper surface of the aggregate in the cup, and allowed to fall freely on to the aggregate. The test sample shall be subjected to a total of 15 such blows each being delivered at an interval of not less than one second.
- 25. 6. The crushed aggregate shall then be removed from the cup and the whole of it sieved on the 2.36mm IS Sieve until no further significant amount passes in one minute. The fraction passing the sieve shall be weighed to an accuracy of 0.1 g (Weight. B). 7.The fraction retained on the sieve shall also be weighed (Weight C) and, if the total weight (C+B) is less than the initial weight (Weight A) by more than one gram, the result shall be discarded and afresh test made. Two tests shall be made.
- 26. 5. Calculation 1.The ratio of the weight of fines formed to the total sample weight in each test shall he expressed as an percentage, the result being recorded to the first decimal place: Aggregate Impact Value = (B/A) X 100 where A = weight in g of saturated surface - dry sample, B = weight in g of fraction passing through 2.36 mm IS Sieve
- 27. SHAPE TEST OF AGGREGATE OBJECTIVE To determine the flakiness and elongation indices of the given aggregate sample. INTRODUCTION The particles shape of aggregates is determined by the percentages of flaky and elongation particles. Flaky and elongation particles are considered undesirable as they cause weakness of the pavement. Rounded aggregates are preferred in cement concrete pavements as the workability of concrete improves. Regular shapes of particles are desirable for granular base course due to increased stability desired from better interlocking. When the shape of aggregates deviates more from the spherical shape, as in the case of angular, flaky and elongation aggregate the void content increase and hence the grain size distribution of the aggregates has to be suitable altered in order to obtain minimum voids in the dry mix on the maximum density.
- 28. THEORY- Flakiness index Aggregate particles are classified as flaky when they have a thickness (smallest dimension) of less than 0.6 of their mean sieve size. The flakiness index of an aggregate sample is found by separating the flaky particles and expressing their mass as a percentage of the mass of the sample tested. This test is not applicable to aggregate passing 6.30mm sieve and retained as 63.0mm sieve. Elongation index Aggregate particles are classified as elongation when they have a length (greatest dimension) of more than 1.8 of their mean sieve size. The elongation index is found by separating the elongation particles and expressing their mess as a percentage of the mass of sample tested. The test is not applicable to material passing 6.30 mm sieve or retained on 50 mm sieve.
- 29. APPARATUS 1. Metal thickness gauge 2. Test sieve size 63mm, 50mm, 37.5mm, 28mm, 20mm, 14mm, 10mm, 6.3mm
- 30. 3. Digital balance 4. Aggregate sample
- 31. PROCEDURE 1.The sieve sample with sieves mentioned in Table 7.1. Weight each of the individual size fractions retained on these sieve, other than the 63.0 mm sieve and store them in separate trays marked with their size. 2. Gauge each fraction from the respective slots in the thickness gauge weigh pieces which pass through the slots. 3. Each sample is gauge in turn of thickness on metal gauge 4. The passing material of each sample is weighed
- 32. 100% PASSING 100% RETAINED MASS PASSING(g) MASS RETAINED 63mm 50mm 0 0 50mm 37.5mm 69 0 37.5mm 28mm 0 0 28mm 20mm 0 97.8 20mm 14mm 11.6 83.6 14mm 10mm 28 1465.1 10mm 6.3mm 54 281.8 NOMINAL APERTURE SIZE THICKNESS GAUGE TOTAL WT. 114g 1928.3g ALL TOTAL WT 2042.3g DATA
- 33. CALCULATION Flakiness index (%) = = (114/2042.3)*100 = 5.6% 𝑀𝐴𝑆𝑆 𝑃𝐴𝑆𝑆𝐼𝑁𝐺 𝑇𝑂𝑇𝐴𝐿 𝑊𝐸𝐼𝐺𝐻𝑇 𝑋 100
- 34. Bituminous materials are one of the oldest and most widely used construction materials. While their components are obtained from finite resources, these materials have long been known as sustainable products due to their capacity to extend their serviceable lives through reclaim, reuse and/or the recycling processes. Asphalt bitumen is a binding organic material made from the by-products of refined crude oil. It is used in road construction because it is easy to produce, reusable, non-toxic, and a strong binder. BITUMINOUS- The bitumen can be classified into the following grade types: 1) Penetration Grade Bitumen. 2) Oxidized Bitumen Grades. 3) Cut Back Bitumen. 4) Bitumen Emulsion. 5) Polymer Modified Bitumen.
- 35. FUNCTION The bitumen has a highly adhesive nature, which keeps the materials in the road mix bind together under strong bonds. These become stronger when the mix is set i.e. ready for vehicle movement. DETERMINATION OF PENETRATION DEFINITION Penetration of a bituminous material is the distance in tenths of millimeter that standard needle will penetrate vertically into a sample under standard conditions of temperature, load and time.
- 36. APPARATUS Standard Penetration apparatus A metal or glass cylindrical flat-bottomed container essentially with the following dimensions Diameter 55mm Internal depth 35mm
- 37. Needle shall be made up of straight, highly polished, cylindrical, hard steel rod. Water bath 10 liters capacity thermostatically Controlled and maintained within the temperature of 25 Thermometer capable of reading temperature up to 250C. PROCEDURE Soften the material to a pouring consistency at a temperature not more than 60C for tars and pitches and not more than 90C for bitumen above the approximate respective softening points. Stir it thoroughly until it is homogeneous and free from air bubbles and water. Pour the melt in to the container to a depth of at least 10mm in excess of the expected penetration.
- 38. Protect the sample from dust and allow it to cool in atmosphere at a temperature between 15 to 30 C for 11/2 to 2hours for 45mm deep container and 1 to 11/2 hours for 35mm deep container. Unless otherwise specified carry out testing at a temperature of 25 + 0.1C. Place it along with the transfer dish in the water bath at 25 + 0.1C and allow it remain for 11/2 to 2hours for 45mm deep container and 1 to 11/2 hours for 35mm deep container. Fill the transfer dish with water from the water bath to a depth sufficient to cover the mould completely. Remove the transfer dish along with the mould from water bath after specified period of time and put on stand.
- 39. Adjust the needle (previously washed, cleaned well with benzene and dried) just to make contact with the surface of the sample. The sum of the weights of the needle, carrier and super imposed weights i.e. The total moving weight shall be 100 0.25grams. Bring the pointer to zero. Release the needle for five seconds and measure the distance penetrated. Make at least three determinations at points on the surface of the sample not less than 10mm apart and not less than 10mm from the side of the dish.
- 40. After each test, return the sample and transfer dish to the water bath and wash the needle with benzene and dry. In case of material of penetration greater than 225 make three determinations on each of two identical test specimens using a separate needle for each determination, leaving the needle in the sample on completion of each determination to avoid disturbance of the specimen. REPORT Express the depth of penetration of the needle in tenths of mm. The value of penetration reported shall be the mean of not less than three determinations whose values do not differ by more than the difference given below
- 41. Penetration Maximum difference 0 to 49 2 50 to 149 4 150 to 249 6 250 and above 8 PRECISION The duplicate results should not differ by more than the following Penetration Repeatability Reproducibility Below50 1 Unit 4 Units Above50 3% of their mean 8% of their mean
- 42. DUCTILITY TEST OF BITUMEN STANDARD IS: 208-1978. DEFINTION The ductility of bituminous material is the distance in centimeters to which it will elongate before breaking when a briquette specimen of the materials is pulled at a specified speed and at specified temperature. APPARTUS Testing machine Mould made up of brass Water bath preferably with a thermostat, 10lit capacity and maintained with in 0.10C of the specified temperature Thermometer 2500C capable of reading up to 0.010C.
- 43. PROCEDURE Unless otherwise specified this test shall be conducted at a temperatures of 27 +0.5C and at a rate of pull of 50 + 2.5mm /min. Melt the bitumen to be tested to a temperature of 75 to 1000C above its approximate softening point till it becomes fluid. Assemble the mould on a brass plate and coated on all the sides with a mixture glycerin and dextrin of equal parts to avoid sticking of the material. Fill the mould until it is more than level full. In filling the mould, pour the material in a thin stream back and forth from end to end of the mould.
- 44. Leave it to cool room temperature for 30 to 40 minutes and than place it in water bath maintained at a specific temperature for 30 minutes. Cut off excess bitumen by means of hot straight edged putty knife level full. Place the brass plate and mould with briquette specimen, in the water-bath and keep at the specified temperature for about 85 to 95 minutes. Remove the briquette from the plate, detach sidepieces and test the briquette immediately. While the test is being conducted, make sure that the water in the tank of the testing machine covers the specimen above by at least 25mm and is maintained continuously with in +0.50C of specified temperature.
- 45. Attach rings at each end of the clips to the hooks in the testing machine and pull the two clips apart horizontally at a uniform speed as specified until the briquette ruptures. Measure the distance in centimeters through which the clips have been pulled to produce rupture. At least three determinations shall be made for each test. Ductility Test
- 46. REPORT Report the average of three normal tests as ductility of the sample, provided that, the three determinations be with in + 5% of their mean value. If the value of three determinations do not lie with in + 5% of their mean but the two higher value are with in + 5% of their mean, then record the mean of the two higher values as the test result. PRECISION The duplicate test results should not differ by more than the values given below Repeatability Reproducibility 10% of mean 20% of mean PRECAUTION In filling the mould care shall be taken to see that no air bubbles shall be formed, and not to disarrange the parts and thus distorting the briquette.
- 47. Cement A cement is a binder, a substance used for construction that sets, hardens, and adheres to other materials to bind them together. Cement is seldom used on its own, but rather to bind sand and gravel together. Cement mixed with fine aggregate produces mortar for masonry, or with sand and gravel, produces concrete. The main function of cement is to act as hydraulic binder, which increases the bond between fragmented particles, so it can enable their use in different fields. The resulted material will have different physical and mechanical properties from the initial materials.
- 50. INITIAL AND FINAL SETTING TIME OF CEMENT 1. Objective For convenience, initial setting time is regarded as the time elapsed between the moments that the water is added to the cement, to the time that the paste starts losing its plasticity. The final setting time is the time elapsed between the moment the water is added to the cement, and the time when the paste has completely lost its plasticity and has attained sufficient firmness to resist certain definite pressure. The temperature of mouldling room, dry materials and water shall be maintained at 27 ± 2°C. The relative humidity of the laboratory shall be 65 ± 5 percent.
- 51. . Apparatus Required 1: Balance On balance in use, the permissible variation at a load of 1000 g shall be ± 1.0 g. The permissible variation on new balance shall be one-half of this value. The sensibility reciprocal shall be not greater than twice the permissible variation.
- 52. 2.vicats Apparatus vicat apparatus should confirm to IS : 5513-1976. It consists of an arrangement to hold the plunger of 10 mm diameter and two other needles which are made to freely fall into a mould filled with the cement paste and the amount of penetration of the needles of plunder can be noted using the vertical graduations from 0 mm to 50 mm.
- 53. 3: Stop Watch 4. Gauging Trowel Gauging trowel conforming to IS : 10086-1982
- 54. 4. Procedure Preparation of Test Block 1. Prepare a neat cement paste by gauging the cement with 0.85 times the water required to give a paste of standard consistency. Potable or distilled water shall be used in preparing the paste. The paste shall be gauged in the manner and under the conditions prescribed in IS:4031 (Part 4)-1988. 2. Start a stop-watch at the instant when water is added to the cement. Fill the vicat mould with a cement paste gauged as above, the mould resting on a nonporous plate. Fill the mould completely and smooth off the surface of the paste making it level with the top of the mould. The cement block thus prepared in the mould is the test block. 3. Immediately after moudling, place the test block in the moist closet or moist room and allow it to remain there except when determinations of time of setting are being made.
- 55. Determination of Initial Setting Time 1. Place the test block confined in the mould and resting on the non-porous plate, under the rod bearing the needle ( C ); lower the needle gently until it comes in contact with the surface of the test block and quickly release, allowing it to penetrate into the test block. In the beginning, the needle will completely pierce the test block. 2. Repeat this procedure until the needle, when brought in contact with the test block and released as described above, fails to pierce the block beyond 5.0 ± 0.5 mm measured from the bottom of the mould. The period elapsing between the time when water is added to the cement and the time at which the needle fails to pierce the test block to a point 5.0 ± 0.5 mm measured from the bottom of the mould shall be the initial setting time.
- 56. Determination of Final Setting Time a) Replace the needle (C) of the vicat apparatus by the needle with an annular attachment (F). b) 2. The cement shall be considered as finally set when, upon applying the needle gently to the surface of the test block, the needle makes an impression thereon, while the attachment fails to do so. c) The period elapsing between the time when water is added to the cement and the time at which the needle makes an impression on the surface of test block while the attachment fails to do so shall be the final setting time. d) 4. In the event of a scum forming on the surface of the test block, use the underside of the block for the determination. 5. Observation And Recording a) Weight of given sample of cement is _ _ _ _ gms b) Volume of water addend (0.85 times the water required to give a paste of standard consistency) for preparation of test block _ _ _ ml c) The normal consistency of a given sample of cement is _ _ _ _ %
- 57. S. No Setting Time (second) Penetration(mm) 1 2 3 Table 1 : Initial and Final Setting Time of Cement 6. Conclusion / Result 1.The initial setting time of the cement sample is found to be ….. (shall be reported to the nearest five minutes.) 2.The final setting time of the cement sample is found to be ….. (shall be reported to the nearest five minutes.) http://civ02.vlabs.ac.in/exp8/index.htm
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