INTERNREPORT ON HIGHWAY SHUDDHASHIL GHOSH 2011UCE1063 ABSTRACT Independent engineer service for development and operation of Chittorgarh Neemuch NH-79 section (Km. 183.000 To Km. 221.400) && Nimbahera-Pratapgarh NH-113 section (Km 5.4000 To 80.000) in the state of Rajasthan through Public Private Partnership (PPP) on Design, Built, Finance, Operate and Transport (the “DBFOT”) basis. PAGE 1 Contents 1. Introduction Project road description Salient features Scope of work 2. Project milestones Project completion schedule and milestone Extension of period 3. Preconstruction activities Status of land acquision Handing/taking over Mobilization of Independent Engineer 4. Quality Control All test for approval of source. Test on aggregates. Test of bitumen. Test for soil, GSB, WMM. Test for DBM. Test for B.C. 5. Structural works Foundation. Sub-structure. Super structure. R.E. wall. Reinforcement. Pouring of concrete. Curing of cement and its importance. PAGE 2 6. Highway construction Various layers of highway, their functions. Construction sequence and methods. Types of machinery used at site. 7. Survey Center line fixit TBM fixit Levelling and checking of levels 8. Documentation- How various works is done in office. PAGE 3 INTRODUCTION PAGE 4 INTRODUCTION National Highway 79 (NH 79) is a National Highway that links Ajmer in Rajasthan and Dhar in Madhya Pradesh. The highway is 500 km long, out of which 220 km is in Rajasthan and 280 km is in Madhya Pradesh. The section of NH-79 from Chittorgarh to Nimbahera & up to Madhya Pradesh border is only 2 lane. The road portion from Chittorgarh to Ajmer has already been developed as 4 lane under GQ. The road portion in Madhya Pradesh from Naya Gaon to Indore has also been developed as 4 lane by Madhya Pradesh State Road Development Corporation. The East & West side of Chittorgarh has been developed as 4 lane road as East West corridor. The Traffic density on Chittorgarh – Madhya Pradesh border is very high and the present road is not capable of sustaining the operational traffic resulting in frequent road blocks & traffic jams. PROJECT ROAD DESCRIPTION 1. Project NH-79 Chittorgarh to Neemuch including Nimbahera bypass, starts from km 183.00 and ends at Km 227.080 in Neemuch, MP border. The project road starts from Chittorgarh which is a famous tourist place and has many cement industries and passes through Nimbahera which is also known for cement industries and stones and finally it ends at Neemuch which is also having Cement Industries, Agriculture Business, and is a Major CRPF Center. 2. As the project road starts and passes through industrial areas, trucks with double and multi axle are the major components of the traffic. 3. The existing highway is generally 2-lane wide except at some places. One ROB at Km 222.160 is also 4-lane. The proposed NH-79 is having two Bypasses namely Shambhupura Bypass (From Km 194+450 to Km 198+000) and Nimbahera Bypass (From Km 209+000 to Km 223+500). The entire stretch traverses through the plain terrain. The pavement is flexible having an earthen shoulder except in urban locations. NH-113 is 240 Km long connecting Nimbahera in Rajasthan and Dahod in PAGE 5 Gujarat, out of which 200 Km is in Rajasthan and 40 Km in Gujarat.The project stretch NH-113 starts at Km 0.00 (Nimbahera) and ends at Km 80.00 (Pratapgarh). The major towns on the project corridor are Nimbahera, Chotti Sadri and Pratapgarh are the towns on NH 113 section. As part of this BoT project, two toll plazas are proposed on NH 113, located at Km 10.00 (Narasinga) and Km 70 (Kulmipura). The project corridor, the main land utilized is agricultural on NH-113. The stretch of NH 113 is currently with intermediate lane and is proposed to be widened to 2 lane with earthen shoulder. PAGE 6 SAILENT FEATURES SR.NO PARTICULARS DESCRIPTION 1 NAME OF PROJECT Development and operation of NH-79 Of Chittorgarh - Neemach (MP Border) Section (PWD Km. 183.000 to Km. 221.400) or (Design Ch. 183.000 to 227.082) by Four Laning and Nimbahera- Partapgarh Section (PWD Km. 5.400 to Km. 80.000) or (Design Ch. 0.000 to 72.915) of NH-113 by Two Laning in the State of Rajasthan through PPP on DBFOT-Toll basis 2 TOTAL LENGTH OF PROJECT 116.997 KMS A NH-79 44.082 KMS B NH-113 72.915 KMS 3 Client / Authority The Chief Engineer, (NH- PWD),Govt. of Rajasthan, Jaipur 4 Independent Engineer Consulting Engineers Group Limited 5 Concessionaire Chetak Tollways Limited (SPV of Chetak Enterprises Ltd.) 6 EPC Contractor Chetak Enterprises Limited 7 Date of signing of Concession Agreement 05-September-2012 8 Appointed date 01-October-2013 9 Schedule Commercial Operation Date (COD) 30-September-2015 PAGE 7 10 Schedule Completion Period of Construction 730 Days from appointed Date (01- Oct-2013) 11 Concession Period 19 Years including construction period SCOPE OF WORK The Scope of Project is as below:- (a) Construction of the Project Highway on the Site set forth in Schedule –A and as specified in Schedule-B together with provision of Project Facilities as specified in Schedule-C, and in conformity with the Specifications and Standards set forth in Schedule-D; (b) Operation and Maintenance of the Project Highway is in accordance with the provisions of the Agreement; (c) Performance and fulfillment of all other obligations of the Concessionaire in accordance with the provisions of this Agreement and matters incidental thereto or necessary for the performance of any or all of the obligations of the Concessionaire under this Agreement. i. Construction of Four Lane Project Highway including Two Bypasses and Construction of Two Lane Project Highways including Two Bypasses, as described in Concession Agreement ii. Operation and Maintenance of the Project Highway in accordance with the provisions of Agreement iii. Performance and fulfillment of all other obligations of the Concessionaire in accordance with the provisions of Agreement. PAGE 8 PROJECT MILESTONE PAGE 9 PROJECT MILESTONE During construction period, the concessionaire shall comply with the requirements set forth in schedule G for each of the project mile stone and the scheduled four / two laning date with in 15 (fifteen) days of the date of each project milestone, the concessionaire shall notify to the Authority of such compliance along with necessary particulars. PROJECT COMPLETION SEDULE AND MILESTONE Sr.no Milestones Period of appointment date Completion date Description Remarks 1 Milestone - I 200th day 19-April-2014 Concessionaire shall have commenced construction of Project Highway and expended not less than 10 % of the total capital cost set forth in the Financial Package. Achieved 2 Milestone- II 410th day 15-Nov-2014 Concessionaire shall have commenced construction of all bridges and expended not less than 35 PAGE 10 % of the total capital cost set forth in the Financial Package. 3 Milestone - III 620th day 13-June-2015 Concessionaire shall have commenced construction of all Project Facilities and expended not less than 70 % of the total capital cost set forth in the Financial Package. 4 Scheduled Completion Date 730th day 01-Oct-2015 Concessionaire shall have completed the Four-Lane Project Highway in accordance with this Agreement. PAGE 11 PRE CONSTRUCTION ACTIVITIES PAGE 12 PRE-CONSTRUCTION ACTIVITIES STATUS OF LAND ACQUISION Consequent to availability of land, the handing over has been completed between authority and concessionaire as per following details, Appointed date has been declares as 01 st Oct. 2013 and work commenced at site as per approved programme and drawings. HANDING AND TAKING OVER PAGE 13 PAGE 14 PAGE 15 MOBILISATION OF INDEPENDENT ENGINEER Independent Engineer has mobilized on the 07th June 2013 and the camp office has been set up at Nimbahera as under: Independent Engineer Consulting Engineers Group Ltd. Plot No. 3-4, Behind Ayyapa Temple Goverdhan Nagar, Nimbahera Distt. Chittorgarh, Rajasthan. Required elements of key personnel and sub-professional staff have also been mobilized at Nimbahera and the Independent Engineer team fully functional. During the development period preceding appointed date of 01 October 2013 required shop drawings have been finalized and good for construction drawings issued to concessionaire. The QA/QC manual and all reporting formats have been finalized details of Independent Engineer set up is as follows: PAGE 16 QUALITY CONTROL PAGE 17 Source of material The contractor shall notify the engineer of his proposed source of materials prior to delivery. If it is found that after trial that sources of supply previously approved do not produce uniform and satisfactory products or if the product from any other source proves unacceptable at any time, the contractor shall furnish acceptable material from other sources at his own expense. 1. BRICKS – brunt clay bricks shall conform to requirements of IS:1077 except that the minimum compressive strength when tested shall not be less than 8.5MPa. for individual bricks and 10.5 MPa. for avg. of 5 specimen. 2. STONES – the stones when emerged in water for 24 hrs. shall not absorb water for more than 5% of their dry weight when tested in accordance to IS:1124. The length of the stone shall not exceed 3 times its height nor shall be less than twice its height plus one joint. 3. CAST IRON – cast iron shall conform to IS:210. The grade no. of the material shall not be less than 14. TEST FOR BITUMEN 1. Penetration test 2. Softening point test 3. Viscosity test 4. Ductility test 5. Marshal test 6. Bitumen extraction PAGE 18 A. Penetration test Aim – to grade the material in terms of its hardness Apparatus – container (55 mm. dia., 35 mm. height), needle (straight highly polished), water bath (maintained at 25 ± 1 o C, 10 liters of water),penetrometer (either manual or electrical), transfer tray, stop water. Procedure 1. Heat the bitumen to 90 o C above the softening point. 2. Pour into the container at least 10mm above the expected penetration. 3. Allow the sample containers to cool in atmospheric temperature for one hour. 4. Place the sample containers in temperature controlled water bath at a temperature of 25 ± 1 0 C for a period of one hour. 5. Fill the transfer dish with water from water bath to cover the container completely. 6. Take off the sample container from the water bath, place in the transfer dish and place under the needle of penetrometer. 7. Adjust the needle to make contact with surface of the sample. 8. See the dial reading and release the needle exactly for 5 ± 0.1 seconds. 9. Note the final reading. 10. The difference between the initial and final readings is taken as the penetration value in one tenth of mm. 11. Make at least three determinations at points on the surface of the sample not less than 10 mm apart and does not less than 10 mm from the side of the dish. The liquid bitumen is stirred thoroughly to remove air bubbles. The atmosphere temperature should not be less than 13 o C. the weight of needle, shaft & additional weight is 100 grams. PAGE 19 Vg 10 -- 80-100 Vg 20 -- 60-80 Vg 30 -- 50-70 Vg 40 -- 40-60 Importance – to determine penetration of bitumen. B. Softening point test Aim – determine softening point of by ball and ring apparatus. Apparatus – ball (steel balls – 2 nos., 9.5 mm dia. 2.5 ± 0.005 gm), ring (brass ring – 2 nos. 6.5 mm dia., with three equally spaced ball guides, inside dia. – 17.5 mm at top and 15.9 mm at bottom), support (used for placing of ring, the upper surface of ring is adjusted to be 50 mm below surface of water. Dist. between bottom of ring and bottom plate is 25 mm), thermometer (0-300 o C, sensitivity – 0.1 o C), bath & stirrer ( a heat resistant glass container of 25 mm dia. & 120 mm depth is used) PAGE 20 Procedure 1. Collect the bitumen. 2. Heat the bitumen to 125 0 – 150 0 C. 3. Heat the rings at same temperature on a hot plate and place it on a glass plate coated with glycerin. 4. Fill up the rings with bitumen. 5. Cool it for 30 minutes in air and level the surface with a hot knife. 6. Set the ring in the assembly and place it in the bath containing distilled water at 5 0 C and maintain that temperature for 15 minutes. 7. Place the balls on the rings. 8. Raise the temperature uniformly @ 5 ± 0.5 0 C per minute till the ball passes through the rings and touches the bottom plate. 9. Note the temperature at which each of the ball and sample touches the bottom plate of the support. 10. Temperature shall be recorded as the softening point of that bitumen. Vg 10 – min. 40 Vg 20 – min. 45 Vg 30 – min. 47 Vg 40 – min. 50 Importance – it gives us idea about the impurities present in bitumen as impurities will lower the softening point. PAGE 21 Importance – to determine presence of impurities. C. Viscosity test Aim – to determine viscosity off bitumen in poise. Apparatus – vacuum pump, water bath, oil bath, cannon- manning vacuum capillary viscometer. Procedure 1. Take bitumen in test tube and temperature of it should be 200 o C. PAGE 22 2. Put the tube in oil bath (in kinetic viscosity meter apparatus) for 10 mins. which is maintained at a temperature of 135 o C. 3. Take of the tube and place in absolute viscosity meter machine in which the water is maintained at a temperature of 60 o C for ½ hrs. 4. Connect the vacuum pump (maintained at 30 mm of Hg.) to the leaner part of the tube. 5. The bitumen starts to rise to the first line (A). 6. When it reaches A line, start stop watch. 7. Note the time it takes to reach the second line(B), similarly note the time it takes to reach the third line (C). Calculations Viscosity 1 =time taken from A to B X correction factor for A to B Viscosity2 = time taken from B to C X correction factor for B to C Viscosityavg. = (viscosity1 + viscosity2)/2 Unit – poise/sec. The correction factor for each tube is given by manufacturer. Vg 10 – 800 Vg 20 – 1600 Vg 30 – 2400 Vg 40 – 3200 PAGE 23 Importance – to determine the rolling temp of bitumen D. Ductility test Importance – the binder should form thin ductile film around aggregate. This proves as satisfactory binder in improving the physical interlocking of aggregates. Aim – to determine ductility. Apparatus – ductility machine, knife, briquette molds. PAGE 24 Procedure 1. The bitumen sample is melted to a temperature of 75 to 1000C above the approximate softening point until it is fluid. 2. It is strained through 90 micron sieve, poured in the mould assembly and placed on a brass plate, after a solution of glycerin and dextrin is applied at all surfaces of the mould exposed to bitumen. 3. After 30 to 40 minutes, the plate assembly along with the sample is placed in water bath maintained at 270C for 30 minutes. 4. The sample and mould assembly are removed from water bath and leveling the surface using hot knife cuts off excess bitumen material. 5. After trimming the specimen, the mould assembly- containing sample is replaced in water bath maintained at 270C for 85 to 95 minutes. 6. The sides of the mould are now removed and the clips are carefully hooked on the machine without causing any initial strain. 7. The pointer is set to zero, the machine is started and the two clips are pulled apart horizontally at a uniform speed of 50 +/- 2.5mm per minute. While the test is in operation, it is checked whether the sample is immersed in water at depth of at least 10mm. 8. The distance, at which the bitumen thread of each specimen breaks, is recorded (in cm) to report as ductility value. Vg 10 – min. 75 Vg 20 – min. 50 PAGE 25 Vg 30 – min. 40 Vg 40 – min. 25 Importance - to determine the elastic property of bitumen PAGE 26 E. Marshal test Aim – determine stability, flow, voids, voids in mineral aggregates, voids filled with asphalt & density of asphalt mixture. Apparatus – specimen mould assembly ( 75 mm high), specimen extractor, compacting hammer (4.kg. , free fall of 475 mmm), compaction pedestal, loading machine (a calibrated proving ring of 5 ton is fixed & a movement of 50 mm/min.), flow meter. Procedure 1. Clean the compaction mould assembly and hammer and keep them pre-heated to a temperature of 95 – 150 Degree Celsius. Place a paper disk in the mould. 2. Take approx. 1200 gm. bituminous mix and place it in a mould. Spade the mixture vigorously with a heated spatula or trowel 15 times around the perimeter and ten times over the interior. 3. Compact by the rammer, with 75 blows on each side, the compacting temperature being 149 Degree Celsius for 60 / 70 grade bitumen. The compacted specimen should have a thickness of 63.5mm. 4. Soon after the bituminous mix specimens have cooled to room temperature, extract them from the mould. 5. Number the specimens and note down the average thickness of each specimen. 6. Keep the specimens immersed under water, in a thermostatically controlled water bath, maintained at 60 plus or minus 1 Degree Celsius for 30 to 40 minutes. 7. Clean the Marshall test head and attach the flow dial gauge. 8. Take the specimens one by one out of water, place in the Marshall Test Head, Keep under the loading machine and apply the load at constant rate of deformation, 51 mm per minute, until failure occurs. PAGE 27 9. Note down the maximum load carried in Kg. before failure (i.e. the stability) and the deformation corresponding to the maximum load in units of 0.25mm (i.e. the flow). 10. Apply the correction to the observed stability if the average thickness of the specimen is not exactly 63.5mm. For BC/DBM (grade 1) - Min. stability (KN at 60 o C) = 900 (for grade 2 – 2000) - Min. flow = 2mm - Max flow = 4mm - No. of blows = 75 on each face - % air voids = 3-6 - % VMA = 10-12 - % VFB = 65-75 Importance – the stability gives us the minimum vertical load that the road can sustain. The flow gives us idea about the elastic property of bitumen, ie, stretching without breaking. The bitumen should only stretch between the specified limits or it will break. PAGE 28 PAGE 29 F. Bitumen extraction by centrifugal extractor Procedure 1. A representative sample (approx.. 500 g) to be exactly weighed and placed in the bowl of the extraction apparatus. 2. Cover the sample with commercial grade Benzene. 3. The mixture is allowed to stand for about one hour before starting the motor. 4. The dried filter ring is weighed and then fitted around edge of the bowl and the cover of the bowl is clamped tightly. 5. A beaker is placed under the drain to collect the extract. 6. The machine is revolved and the speed is maintained till the solvent ceases to flow from the drain. 7. The machine is allowed to stop and 200ml of benzene is added to the bowl and the procedure is repeated. 8. The filter ring is removed, the residual material is dried first in air and then in oven at constant temperature of 110 0 C ± 5 0 C till constant weight is obtained (W1). 9. Filter the extract through a filter paper. 10. Dry the filter paper in the oven and determine the weight of fines attached to filter paper (W2). 11. Determine the amount of mineral matter in the extract (W4). 12. Calculate the % bitumen in the test portion as follows: 13. Bitumen Content, % = [ { W - (W1+W2+W4) } / (W1) ] x 100 PAGE 30 Importance – to determine if adequate bitumen is added to aggregate. SOME INFO. a. The bitumen is brought to sufficient fluidity or viscosity before use in pavement const. by any one of the following 3 methods - By heating in form of hot bitumen binder. - By dissolving in light oils in form of cutback bitumen. - By dispersion of bitumen in water, in form of bituminous emulsion. b. The paving bitumen in India is classified in 2 categories. - Paving bitumen from Assam Petroleum denoted as A-type. - Paving bitumen from other sources denoted as S-type. c. Cutback bitumen – is defined as the bitumen the viscosity of which has been reduced by a volatile diluent. For use in surface dressing and some types of bituminous macadam. Cutback bitumen is available in three types PAGE 31 - Rapid curing - Medium curing - Slow curing d. Bitumen emulsions – is a liquid product in which a substantial amount of bitumen is suspended in a finely divided condition in an aqueous medium and stabilized by means of one or more suitable materials. The main advantage of emulsions are that - They can be used without heating. - Particularly useful for patch repair works. - Can be used even when surface is wet or when its raining. 3 types of emulsions can be prepared. - Rapid setting (RS) – for penetration and surface treatment. - Medium setting (MS) – used for plant mixes with coarse aggregate. - Slow setting (SS) – used for fine aggregate mixes. PAGE 32 e. Additive – any substance which is added in small amount to bitumen to impart some particular properties. Eg. Improved adhesion, emulsification, etc. f. Antifoam agent – a substance like silicon oil which when added to bitumen will reduce the surface tension and hence frothing of hot bitumen in presence of water. g. PMB – bitumen binder containing selected polymers to produce enhance performance characteristics. Vg 40 Used in highly stressed areas such as those in intersections, near toll booths and parking lots. Vg 30 Used for paving in most of India. Vg 20 Used for paving in cold climates, high altitude of North India. Vg 10 Used in spraying application (tack coat, prime coat) and for paving in very cold climates. PAGE 33 TEST ON CEMENT AND CONCRETE 1. Normal consistency of cement. 2. Initial and final setting time. 3. Soundness of cement. 4. Workability of concrete. 5. Compressive strength of concrete. A. Normal consistency of cement Apparatus – vicat apparatus with plunger (10mm dia.) Theory – the standard consistency of cement is defined as that consistency at which the vicat plunger penetrate to a point 5 to 7 mm from bottom of vicat mould. Procedure 1. Weight 400 g. of cement and place it on a glass plate. Mix with water, starting from 25% and prepare a paste. 2. Fill the paste in Vicat mould without forming any air bubbles and strike off the excess paste. The time of gauging is not less than 3 mins. , nor more than 5 mins. The gauging time shall be counted from the time of adding water to the dry cement until commencing to fill the mould. 3. Place and filled mould under the plunger of Vicat apparatus. Lower the plunger gently to touch the surface of the test block and quickly release. 4. Note the reading of penetration, when the plunger stops penetrating. PAGE 34 5. Repeat the test with increased percentage of water till the plunger penetrates to a point, 5 to 7 mm from the bottom of the mould. 6. The percentage of water (amount of water as a percentage by Wt. of the Dry cement) corresponding to that particular penetration, gives the normal consistency of cement. The room temperature should be 27 o ± 2 o C. Importance – to determine the water content for test of soundness and initial and final setting time. B. Initial and final setting time Apparatus – the vicat apparatus Initial setting time 1. Prepare a cement paste with water equal to 0.85 P (P – normal consistency of cement) start the stop watch at the time of adding the water to the cement. 2. Fill the paste in the Vicat mound and smooth off the surface. 3. Place the mould under the rod of Vicat apparatus, under the rod bearing the needle. Lower the needle gently to bring it in contact with the surface of the mould, and quickly release. 4. Note down the penetration of needle. 5. Repeat the procedure of penetration until the needle fails to penetrate beyond a point, 5 0.5 mm from bottom of the mould. 6. The time period elapsed between the instant at which water is added to the cement to the time at which the needle gives the specific penetration; gives the initial setting time of the cement. PAGE 35 Final setting time 1. Replace the needle of Vicat apparatus by a needle with an annular attachment. 2. Lower the angular attachment to the surface of the test block and gently release. 3. Repeat this procedure until the needle makes an impression on the surface of the mould, while the annular attachment fails to do so. 4. Note down the time elapsed between the instant at which water is added to the cement, to the end point specified, which gives the final setting time of the cement. Initial setting time min. – 30 mins Final setting time max. – 600 mins Importance – to determine the time in which we have to mix the concrete and place it. C. Soundness of cement (le chartlier method) Apparatus – small split cylinder of spring brass or other suitable metal of 0.5 mm thickness, forming a mould of 30mm dia. & 30mm. high. On either sides are attached 2 indicators with pointed ends & dist. between cylinders and ends is 165 mm. Procedure 1. Prepare a cement paste with quantity of water equal to 0.78 P (P Normal consistency of cement). 2. Fill the mould of Le-Chartlier apparatus, with the paste, place it on a glass plate. Place another glass plate on the top. 3. Immediately place the whole assembly in water maintained at 27 0 c. 4. After 24 hours, determine the distance between pointers, nearest to 0.5mm. PAGE 36 5. Place the mould in a water bath and heat the water to boiling and keep the mould at that temperature for three hours. 6. Remove the mould from water, allow to cool and again measure the distance between the pointers. 7. The difference between the initial and final measurements of the distance between the pointers, represent the soundness of cement which is expressed in mm. Important - Expansion should not be more than 10 mm. D. Compressive strength of concrete Apparatus – testing machine (10 KN least count). Age at test – 3, 7, 14 & 28 days. No. of specimen – at least 3 specimens from different batches for each selected age. Procedure 1. Fill the mould with freshly mixed concrete in 3 equal layers, compact it with tamping bar giving 35 blows in each layer uniformly and finally level off with the trowel. Mark the date of casting, cube no and the identification of member. 2. Keep the specimen in moist air of at least 90% relative humidity and at a temp of 27 plus or minus 2 Degree Celsius for 24 hours. Alternatively, cover the moulds with wet gunny bags. 3. After specified time period is over remove the specimen from the mould and submerge it in clean fresh water, maintained at a temp of 27 plus or minus 2 Degree Celsius till the cube is ready is for test. 4. Take out the cube after for 3,7,14, 28 days as required and wipe off the surface water with cloth. PAGE 37 5. Note down the dimensions and weigh the cube and then place it in the compression testing machine. 6. Apply the load on the cube at the rate of 140 Kg / Sq. cm. / Min. till it fails. Record the maximum load applied. 7. The compressive strength is calculated in N / MM 2 by dividing the maximum load taken in Newtons by the cross sectional area of the cube calculated from the mean dimension of the section 3 days – 40% compaction 7 days – 72% compaction 28 days – 100% compaction Taking an example of M30 grade concrete on 3 th day testing 0 20 40 60 80 100 120 0 5 10 15 20 25 30 % compaction PAGE 38 (Theoretical) Since the test is done on 7 th day the compaction is 72 % Hence the strength of concrete is = 72/100 × 30 × area of cube ( 15 × 15 = 225 cm 2 ) = 4860 (Practical) Put the block in machine and record the reading upto which the dial stops. Let it be x x/ area(22.5) = strength - Take 3 readings - Take avg. of three readings ( suppose y) - Take 15% of the avg. The variations in the reading should be between y ± 0.15y. Generally the readings comes greater than the theoretical value. Importance - to know how much strength is developed in the concrete after a specific period of time. E. Slump test Apparatus -1) Mould in form of frustum of a cone whose dimensions are as follows: top dia. – 10mm. bottom dia. – 20 mm. height – 30 cm. 2) Tamping rod (16 mm dia., 0.6 meter long) PAGE 39 Procedure 1. Clean the internal surface of the Slump mould thoroughly. 2. Fill the concrete sample in the mould in 4 layers, each layer approximately ¼ of the height of the mould. 3. In case of the concrete containing aggregate of maximum size more than 38 mm, the concrete shall be wet-sieved through 38 mm screen to exclude aggregates particles bigger than 38 mm. 4. Tamp each layer 25 times by tamping rod. 5. When the mould is filled, cut off the excess concrete, to the level of the top of the cone. 6. Immediately remove the mould, by raising it slowly in vertical direction, allowing the concrete to subside. 7. Place the mould by the side of subsided concrete. 8. Measure the difference in level between the height of the mould and the highest point of the concrete, in millimeters, and record it as slump. 9. Inspect the type of slump and record it. Importance – to determine the workability of concrete SOME INFO. a. As the water content increases the strength of concrete decreases. b. Hence high slump concrete will have more workability but less strength. c. Slumps of some structural parts Raft 40-50 mm. Pier 50-70 mm. PCC 30 mm. PAGE 40 d. More workability means internal friction is reduced TEST ON SOILS 1. Free swell index 2. CBR 3. Determination of MDD (proctor test) 4. Liquid limit 5. Plastic limit 6. Flakiness and elongation index 7. FDD by sand replacement method A. Free swell index Procedure 1. Take 2 samples of 10 g each of oven dried soil passing through IS 425 micron sieve. 2. Pour soil specimens in 2 separate glass graduated cylinders of 100 ml capacity. 3. Fill are cylinder with kerosene and the other cylinder with distilled water up to 100 ml mark. 4. Stir the sample gently to remove entrapped air and allow it to stand for 24 hours. 5. The difference in readings of both the cylinders shall be expressed in % of volume of soil in kerosene, to give the free swell index of soil. PAGE 41 Importance – to determine the quality of soil and can the road be constructed on it. B. CBR testing (static and dynamic method) Compaction by static method 1. Find the weight of oiled empty CBR mould with base plate and filter paper placed in. 2. Calculate the weight of soil required at OMC by using the formula. CBR= % of compaction required x MDD (in g / CC) x (1+OMC)/100 x Volume of mould 3. Take 6 Kg. of dry soil and mix it thoroughly after adding the quantity of water required to bring it to a state at which it can be compacted to attain its maximum dry density. 4. Take the required quantity from this as calculated above. 5. Place this soil in the mould in 2 or 3 layers by ramming the layers lightly by a disc so that a leveled surface is attained. 6. Over the compacted specimen place one spacer disc approximately equal to 1/3 rd height of the compacted specimen. 7. Then compress it in a compressing machine or any similar suitable apparatus till the spacer is just pushed to the top of the mould. Remove the spacer disc. Compaction by dynamic method 1. Take 5 - 6 Kg. of oven dried soil. 2. Add water (optimum water content required to attain max. dry density) to it and mix it thoroughly. 3. Take the empty weight of oiled CBR mould. 4. Fit the collar to the mould. 5. Place a spacer disc in it and then place one filter paper over it. 6. Then, fill the soil mixture in the mould in 5 layers by giving 10 blows to each layer. PAGE 42 7. Remove the collar and trim it off by a straight edge. 8. Then remove the mould from base plate, take the spacer disc out. 9. Invert the mould and fix it in position on the base plate after placing a filter paper. Finding degree of compaction & swell index 1. After compaction, weigh the mould with specimen. 2. Find the weight of the specimen. 3. Take a portion of the remaining sample left in the tray and find the moisture content. 4. Find the dry density and compare it with the maximum dry density and find the degree of compaction (%) by comparing this with the maximum dry density. Determination of swell index 1. After weighing the moulds, place the surcharge weights (Equal to the Wt. of Pavement) to the nearest 2.5 kg a perforated disk connected with an adjustable stem place this assembly in the mould. 2. Place the tripod having the micrometer in place and adjust the stem to touch the micrometer indicator and find the initial reading on the micrometer. 3. Then place the mould in water tank and soak for 96 hours. 4. After 96 hours, find the micrometer reading. 5. Find the difference in reading. 6. Find the swell index by dividing the swell by the height of the specimen before soaking. Express this in percentage. CBR testing 1. After 96 hours of soaking and after measuring the swell, find the weight of the mould with soaked specimen. PAGE 43 2. Drain the excess water by keeping the specimen vertically or by tilting for 10-15 min (for sandy specimen no titling is required.) 3. Remove the filter paper on the specimen and keep it in the CBR testing machine. 4. Place the same surcharge weight used when soaking. 5. Adjust the penetration measuring micrometer on the platform on which the CBR mould containing the specimen rests, to show penetration when the specimen is loaded. 6. The plunger shall be seated under a load of 4 kg so that full contact is established between the surface of the specimen and the plunger. 7. Start loading the specimen at the rate of 1.25 mm/min, after adjusting the penetration dial and the proving ring to zero mark. 8. Note the deflections in the dial gauge of the proving ring for corresponding penetrations as per the requirement. (in our case, deflections, are noted for penetrations of 0.5, 1, 1.5, 2, 2.5, 3, 4,5, 7.5, 10, 12, 12.5mm of the plunger). 9. Convert the deflections in to loads and plot them against penetrations (in mm). 10. Find any correction required to be applied for the loads (when an S-type curve is formed the lower bend can be corrected by drawing a straight line. 11. Correct the loads by shifting the points actually plotted, (if a correction of 0.5 is observed, instead of taking deflection for penetration of 2.5mm, deflection for 3mm shall be taken). 12. Take the load for 2.5mm and 5mm (for corrected curves, corrected load shall be taken). 13. Take the load for 2.5mm and 5mm (for corrected curves, corrected load shall be taken). PAGE 44 14. Find the CBR values for these penetrations by using the formula. 15. CBR = PT × 100/ Ps 16. Where PT = Load corresponding to the chosen penetration. Ps = Standard load corresponding to the chosen penetration as for PT taken from the table given below. Penetration depth (mm) Total standard load (kgf) 2.5 1370 5.0 2055 17. The CBR value shall be considered grater of the two values. 18. Repeat the same procedure with 35 & 65 blows respectively. 19. Draw a graph between the Dry Densities and the CBR Values. Calculate the CBR at required % of compaction (Dry Density). C. MDD test Procedure 1. Take the weight of the mould and the soil (m2). 2. Find out the water content as per IS 2720 Part-II. 3. Calculate the Bulk Density and Dry Density. 4. Repeat the same procedure for various percentages of water until the weight of the mould + soil attains a peak and starts reducing with increase in water content. So that a minimum of 5 points are available to plot the graph between dry density and moisture content. 5. By using the graph between dry density and moisture content, find the maximum dry density and the corresponding moisture content and report as MDD and OMC, respectively. PAGE 45 6. For compacting soil containing coarse material up to 37.5 mm IS Sieve, the 2250 cc mould should be used. A sample weighing about 30 kg is used for the test. Soil is compacted in 5 layers, each layer being given 55 blows of 4.9 kg rammer. 7. Take the weight of the mould and the soil (m2). 8. Find out the water content as per IS 2720 Part-II. 9. Calculate the Bulk Density and Dry Density. 10. Repeat the same procedure for various percentages of water until the weight of the mould + soil attains a peak and starts reducing with increase in water content. So that a minimum of 5 points are available to plot the graph between dry density and moisture content. 11. By using the graph between dry density and moisture content, find the maximum dry density and the corresponding moisture content and report as MDD and OMC, respectively. 12. For compacting soil containing coarse material up to 37.5 mm IS Sieve, the 2250 cc mould should be used. A sample weighing about 30 kg is used for the test. Soil is compacted in 5 layers, each layer being given 55 blows of 4.9 kg rammer. 13. FDD/MDD = 98% for subgrade & 95% for embankment. Height of fall of hammer = 180 cm Mould height = 18 cm PAGE 46 Collar height = 6.5 cm Dia. of mould = 17 cm ATTERBERG LIMITS D. Liquid limit (casagrande apparatus) Procedure 1. Take 120gm of specimen passing 425-micron IS Sieve and mix it thoroughly with distilled water, to form a uniform paste. 2. Take a portion of the paste and place it in the cup above the spot where the cup rests on the base, squeezed down and spread. 3. Trim to a depth of one centimeter at the point of maximum thickness, returning the excess soil to the dish. 4. Cut the soil in the cup with the standard grooving tool, along the center line of the cam follower so that a clean, sharp groove of proper dimensions is formed. 5. Immediately start rotating the handle at a rate of 2 revolutions per second. 6. Count the number of blows till both the parts of the sample come into contact at the bottom of the groove, along a distance of about 12mm. 7. Record the number of blows and determine the moisture content of the sample, taken near the closed groove at right angles to the groove. 8. Repeat the test by adding soil mixture, so that the number of blows to close the groove is between 35 and 15. PAGE 47 9. Plot a graph with number of blows in logarithmic scale and corresponding moisture content in natural scale, and fit a straight line. 10. Read the moisture content corresponding to 25 number of blows from the graph, which gives the liquid limit of the soil. E. Plastic limit Procedure 1. Mix about 20gm. of soil passing 425-micron IS Sieve, with distilled water. 2. Take approximately 8 gm. of soil from the mix. Make a ball and roll it on a glass plate, with hand to make a thread. 3. When the diameter of 3mm is reached re-mould the soil again to a ball. Keep 3mm MS bars to have dia. comparison. 4. Repeat the process of rolling and re-moulding until the thread crumbles under the pressure required for rolling and the soil no longer be rolled into a thread. 5. The crumbling may occur when the thread has a diameter greater than 3 mm. This shall be considered a satisfactory end point, provided the soil has been rolled in to a thread 3 mm in diameter immediately before. 6. At no time shall an attempt be made to produce failure at exactly 3 mm diameter by allowing the thread to reach 3 mm, then reducing the rate of rolling or pressure or both and continuing the rolling without further deformation until the thread falls apart. 7. Determine the moisture content of the crumbled threads. 8. Repeat the test twice more, with fresh portion of the soil mix. 9. The average of moisture contents determined in the three trials, gives the plastic limit of the soil. PAGE 48 F. Flakiness and elongation index Procedure 1. Take a representative sample and sieve the sample through IS sieve 63,50, 40, 31.5, 25, 20, 16,12.5,10 and 6.3mm 2. Separate the flaky material by using the standard flakiness gauge. 3. Take the wt. of flaky material which passes through standard gauge. 4. The flakiness index = weight of material passing the gauge × 100 / total weight of sample 5. Take the non-flaky portion of the sample tested and take weight (W2 gm). 6. Separate elongated material by using standard elongation gauge and take weight. 7. The Elongation Index = Wt. of elongated particles × 100 / Sample Tested (W2) 8. Combined Flakiness and Elongation Index = FI + EI. G. FDD by sand replacement method Procedure 1. Clean and level the surface. 2. Place the metal tray with central hole on the prepared surface. 3. Excavate a hole 150mm deep / and collect the excavated material in a container (Polythene bags). PAGE 49 4. Take the weight of the excavated soil / material. 5. Pour the standard sand (passing 1 mm and retaining 600- micron) in the cylinder upto top (leave 1-cm from top) and take the weight. 6. Place the sand pouring cylinder centrally over the excavated hole. 7. Open the shutter till the sand fills the excavated hole and the cone completely (Seeing the movement of sand in the Cylinder). 8. Close the shutter and take the weight of the cylinder with remaining sand. 9. Determine the moisture content of excavated soil / material. 10. Determine the bulk & dry densities of excavated soil 11. Calculate the degree of compactions by comparing the field dry density with the MDD determined in the laboratory. W = fixed for every cylinder (weight of sand in cone) Ww = weight of sample W1 = weight of sand + cylinder (before pouring) W2 = weight of sand + cylinder (after pouring) W3 = W1 - W2 – W W3 = (weight of sand in hole) V (volume of hole) = W3/ρs (fixed for every cylinder) Φb = Ww/V FDD = φb × 100 / (1+m) m= OMC PAGE 50 SOME INFO. 1. If P.I. > 45%, there will be crack in case of vertical load. P.I. = LL – PL 2. FSI – if testing is done, there should not be more than 50% FSI 3. CBR – it give us an idea about how strong is the ground. The project’s CBR is 13. 4. The more the CBR, the less is the thickness required. 5. In bitumen mixes and bases (SG, GSB, WMM) we do not need flaky particles as they tend to break up during rolling process. 6. FI - % by weight of particles whose least dimension (i.e. thickness) is less than three fifths of mean dia. 7. EI - % by weight of particles whose largest dimension (i.e. length) is greater than one & fourth-fifths times its mean dimension. PAGE 51 STRUCTURE PAGE 52 RETAINING WALL Retaining walls are structures designed to restrain soil to unnatural slopes. They are used to bound soils between two different elevations often in areas of terrain possessing undesirable slopes or in areas where the landscape needs to be shaped severely and engineered for more specific purposes like hillside farming or roadway overpasses. A retaining wall is a structure designed and constructed to resist the lateral pressure of soil when there is a desired change in ground elevation that exceeds the angle of repose of the soil. 1. Gravity walls depend on their mass (stone, concrete or other heavy material) to resist pressure from behind and may have a 'batter' setback to improve stability by leaning back toward the retained soil. For short landscaping walls, they are often made from mortarless stone or segmental concrete units (masonry units). Dry-stacked gravity walls are somewhat flexible and do not require a rigid footing in frost areas. Home owners who build larger gravity walls that do require a rigid concrete footing can make use of the services of a professional PAGE 53 excavator, which will make digging a trench for the base of the gravity wall much easier. 2. Cantilevered retaining walls are made from an internal stem of steel- reinforced, cast-in-place concrete or mortared masonry (often in the shape of an inverted T). These walls cantilever loads (like a beam) to a large, structural footing, converting horizontal pressures from behind the wall to vertical pressures on the ground below. Sometimes cantilevered walls are buttressed on the front, or include a counterfort on the back, to improve their strength resisting high loads. Buttresses are short wing walls at right angles to the main trend of the wall. These walls require rigid concrete footings below seasonal frost depth. This type of wall uses much less material than a traditional gravity wall. 3. Sheet pile retaining walls are usually used in soft soils and tight spaces. Sheet pile walls are made out of steel, vinyl or wood planks which are driven into the ground. For a quick estimate the material is usually driven 1/3 above ground, 2/3 below ground, but this may be altered depending on the environment. Taller sheet pile walls will need a tie- back anchor, or "dead-man" placed in the soil a distance behind the face of the wall, that is tied to the wall, usually by a cable or a rod. Anchors are then placed behind the potential failure plane in the soil. 4. An anchored retaining wall can be constructed in any of the aforementioned styles but also includes additional strength using cables or other stays anchored in the rock or soil behind it. Usually driven into the material with boring, anchors are then expanded at the end of the cable, either by mechanical means or often by injecting pressurized concrete, which expands to form a bulb in the soil. Technically complex, this method is very useful where high loads are expected, or where the wall itself has to be slender and would otherwise be too weak. PAGE 54 Cantilever retaining wall R.E. WALL (segmental retaining wall) Segmental retaining wall consists of modular concrete blocks that interlock with each other. They are used to hold back a sloping face of soil to provide a solid vertical front. Without adequate retention the slopes can cave, slump or slide. Segmental retaining wall consists of a facing system and a lateral tieback system. The facing system usually consists of modular concrete blocks that interlock with each other and with the lateral restraining members. The PAGE 55 lateral tiebacks are usually geogrids that are buried in the stable area of the backfill. In addition to supporting the walls the geogrids also stabilizes the soil behind the walls. These two factors allow higher and steeper walls to be constructed. To build a RE wall we use segmental blocks of concrete. These are pre cast blocks and they come in many shapes and sizes. The segmental blocks have a key made so they interlock with each other without the need of any mortar. First we excavate the ground upto which the wall has to be made. The depth of excavation is more in the central portion of flyover than the ends. After excavating we do PCC in the base the dimensions are as shown: After doing PCC we place the blocks one over other till it reaches the required height. We ram filler material in the blocks so that they don’t move by increasing the overall weight and friction of the block. The thickness of the filler material per layer is equal to the thickness of the segmental block, i.e. 200mm We also use geo grit as to make a grip on blocks. Geo grit is attached after 1 st , 3 rd , 7 th , 10 th , 13 th , 16 th , 19 th ….etc. The advantages of R.E. wall over the conventional reinforcement wall are :- 1. More economical 2. Easy to construct 3. No curing required 4. Structure is constructed quickly 5. No specially skilled labour required. 6. No problem of rusting of reinforcement. 7. Horizontal and vertical curvatures 8. A wide variety of colors, sizes and textures. 9. Easy grade changes. PAGE 56 10. No need for a concrete footing. But the conventional one has greater strength and durability than the RE. We use baby rollers only for the compaction of filler media. We don’t use bigger rollers as they can displace the blocks from their alignment and due to their bigger size they can damage the blocks if attention is not paid. Geo grit Filler material Key PAGE 57 Segmental retaining wall SUPERSTRUCTURE A superstructure is an upward extension of an existing structure above a baseline. This term is applied to various kinds of physical structures such as buildings, bridges. In order to improve the response during earthquakes of buildings and bridges, the superstructure might be separated from its foundation by various civil engineering mechanisms or machinery. On a bridge, the portion of the structure that is the span and directly receives the live load is referred to as the superstructure. In contrast, the abutment, piers, and other support structures are called the substructure. PAGE 58 SUBSTRUCTURE 1. In buildings the substructure consists of foundation. 2. In bridges the abutment, piers, and other support structures including the foundation is called substructure. Its function is to transmit the load to the ground. It provides a base. CURING OF CONCRETE AND ITS IMPORTANCE Curing is the process in which the concrete is protected from loss of moisture and kept within a reasonable temperature range. This process results in concrete with increased strength and decreased permeability. Curing is also a key player in mitigating cracks, which can severely affect durability. Concrete bridges require a higher standard of curing to achieve the low permeability required for protection of steel reinforcement. Standard recommendations for curing bridge decks is moist curing for a minimum of seven days for concrete mixtures containing only portland cement and as long as 14 days when supplementary cementing materials are included in the concrete mixture. Some states also require the application of curing compound upon removal of the moist curing methods. PAGE 59 Curing of concrete using gunny bags FOUNDATION A foundation is the lowest and supporting layer of a structure. Foundations are generally divided into two categories: shallow foundations and deep foundations 1. Shallow foundation Shallow foundations, often called footings, are usually embedded about a metre or so into soil. One common type is the spread footing which consists of strips or pads of concrete (or other materials) which extend below the frost line and transfer the weight from walls and columns to the soil or bedrock. Another common type of shallow foundation is the slab-on- grade foundation where the weight of the building is transferred to the soil through a concrete slab placed at the surface. Slab-on- grade foundations can be reinforced mat slabs, which range from PAGE 60 25 cm to several meters thick, depending on the size of the building, or post-tensioned slabs, which are typically at least 20 cm for houses, and thicker for heavier structures. 2. Deep foundation A deep foundation is used to transfer the load of a structure down through the upper weak layer of topsoil to the stronger layer of subsoil below. There are different types of deep footings including impact driven piles, drilled shafts, caissons, helical piles, geo-piers and earth stabilized columns. The naming conventions for different types of footings vary between different engineers. Historically, piles were wood, later steel, reinforced concrete, and pre-tensioned concrete. Types of shallow foundation 1. Strip footing The strip footing is employed in case of a load-bearing wall. The strip footing is also used for a row of columns that are very closely held and spaced such that their spread footing overlap or tends to nearly touch each other. In such cases it is more economical and effective to use a strip footing than to use a number of spread footings held in a single line. Thus, a strip footing is also called as continuous footing. 2. Spread footing The spread/isolated/pad footing is generally constructed to support an individual column. The spread footing may be circular, square or rectangular slab of uniform thickness. Sometimes it may be designed as stepped or to spread/distribute the load over a larger area. 3. Combined footing The combined footing is designed to support two parallel columns. It is principally used when the two columns are so close that to one PAGE 61 another that their individual footing would overlap. The combined footing may also be constructed when the property line is so close to column that a spread footing gets eccentrically loaded if kept within the property lines. Thus, by combining it with that of an interior column, the load gets evenly/uniformly distributed. The combined footing may be rectangular or trapezoidal. 4. Raft foundation The mat/raft foundation is a big slab supporting a number of columns and walls its entire structure or in a large part of the structure. The mat is efficient when the permissible soil pressure smaller or where the columns and walls are very close such that individual footing gets overlap or nearly touched each other. The mat foundations are efficient in eliminating the differential settlement on the non-homogeneous soils or where there is a large variation in loads on the individual columns. PAGE 62 TYPES OF DEEP FOUNDATION 1. Pile foundation Piles are relatively long, slender members that transmit foundation loads through soil strata of low bearing capacity to deeper soil or rock strata having a high bearing capacity. They are used when for economic, constructional or soil condition considerations it is desirable to transmit loads to strata beyond the practical reach of shallow foundations. In addition to supporting structures, piles are also used to anchor structures against uplift forces and to assist structures in resisting lateral and overturning forces. 2. Pier foundation Piers are foundations for carrying a heavy structural load which is constructed in situ in a deep excavation. PAGE 63 Pier foundation at chainage 217+695 3. Well foundation Caissons are a form of deep foundation which are constructed above ground level, then sunk to the required level by excavating or dredging material from within the caisson. CULVERTS A culvert is a structure that allows water to flow under a road, railroad, trail, or similar obstruction. Typically embedded so as to be surrounded by soil, a culvert may be made from a pipe, reinforced concrete or other material. A structure that carries water above land is known as an aqueduct. Culverts may be used to form a bridge-like structure to carry traffic. Culverts come in many sizes and shapes including round, elliptical, flat-bottomed, pear- shaped, and box-like constructions. Culverts may be made of concrete, galvanized steel, aluminum, or plastic, typically high density polyethylene. PAGE 64 Two or more materials may be combined to form composite structures. For example, open-bottom corrugated steel structures are often built on concrete footings. Plastic culvert liners are also inserted into failing concrete or steel structures in order to repair the structure without excavating and closing the road. To prevent the older structure from collapsing, the space between it and the plastic liner is usually filled with grout. 1. BOX CULVERT They are used for water passage, generally seasonal/ brief. Rest of year used by wildlife. They have concrete base floor & have more room than pipe arch for wildlings. 2. PIPE ARCH Generally made of steel or concrete. Main use is passage of water but sometimes also used by wild animals. Pipe culverts have inner diameters of 60 cm, 100 cm, 140 cm and 150 cm. At the beginning these culverts were made of reinforced concrete pipes produced on the site; the length of the pipe was 1 m. used on a large scale for forest road building due to their advantages over other construction solutions: · ease to handle; · fast execution without problems; PAGE 65 · short time of execution; · rapid putting into service; · smaller costs compared with other solutions. The major disadvantage of these culverts is clogging with material from the slopes, which may put the culverts out of service. 3. SLAB CULVERTS Slab culverts have a clearance span between abutment faces of maximum 4 m. Small culverts with a clearance of 0.5 m and 1 m have been used in 1960-1961 and then replaced by pipe culverts. The culverts with a clearance of 2 to 4 m were first designed and realized with reinforced concrete cast in situ and, starting in 1964-1965 the use of factory-made prefab reinforced concrete was introduced CROSS BARRIERS PAGE 66 On top of culverts we use cross barriers. They are made of high strength concrete (M50) as they can be hit by vehicles. They serve as protection. The main reinforcement comes from the slab and the sloping part is formed by the binder of the slab. TYPES OF BRIDGES 1. Culverts 0 to4m 2. Minor bridge 4 to 30 m 3. Major bridge 30 and above M15 M20 M30 M35 M50 PCC WALL RAFT CURB CROSS BARRIER SLAB CRUBS They are made along the side of the road. They are cast in-situ by machine. The casting is a continuous process. PAGE 67 Curb casting Level checking of curb PAGE 68 HIGHWAY CONSTRUCT- -ION PAGE 69 DIFFERENT TYPES OF MACHINES USED IN HIGWAYS 1. DBM/HM plant 2. Crusher 3. WMM plant 4. Dumper 5. Loader 6. Weight bridge 7. Sprayer 8. Excavator 9. Rollers 10. Grader 11. Bitumen plant 12. JCB 13. Paver A. DBM / HM Plant An HM plant is a plant used for the manufacture of DBM and BC. There are three main classes of plant: batch heater, semi- continuous (or "asphalt plant"), and continuous (or "drum mix"). The batch heater has the lowest throughput, the continuous plant the highest at up to around 500 Tonnes per hour There are two cabins in HM plant 1. Cold bin – controls the tanks A, B, C, D by increasing or decreasing the RPM of the motors attached to these tanks. Increasing the rpm will increase the agg. Quantity. PAGE 70 2. Hot bin – it controls the sieves. We feed the recipe to the computers and only that specified amount of material will fall in mixer How it works 1. A plant runs material from various cold feed hoppers into a heater drum, where the batch is then heated up to temperature. 2. The hot aggregate is screened into numerous hot bins (depending on the various aggregate sizes).Each hot bin releases a certain amount of aggregate into a weigh hopper, then it is discharged into a mixing drum where (dry) filler and binder are added. 3. The blend is mixed and discharged either directly into the delivery vehicles or into a small weighing and collecting hopper. To increase throughput, the heater can be heating the next batch while the previous is being mixed. We use blowers to heat the aggregates so that the heat reaches deep inside the heating chamber. We heat the aggregates because any water present will decrease the efficiency of bitumen to bind with it. The fuel used to heat is called LDO PAGE 71 B. CRUSHER When material comes from supplier in dumpers its crushed and graded to the specified size. But sometimes if good quality aggregate is available near by then companies instead of buying install crushers on the site. The raw material is put inside it where it gets crushed to the required sizes. It then sieves the crushed agg. And places them in different heaps. PAGE 72 C. WMM PLANT Its working is same ass the HM plant but here we don’t heat the agg. and use water in place of bitumen. The water content is decided by MDD and OMC we get from the lab. If it comes say 7 % then we use 8% in WMM plant as some water can get vaporized. PAGE 73 D. DUMPER / TRIPPER Its used to carry materials like BC, DBM, GSB etc to respective sites and bringing aggregates to the plant. PAGE 74 E. LOADER The widely used companies in India are Hindustan and Volvo. They are used to load the material either in dumper or at site. The carrying capacity of a loader is 2 tonnes. Sometimes caterpillar loaders are also used in hilly areas. The caterpillar loaders have their tires replaced iron chains which helps to grip the ground more strongly. F. WEIGHT BRIDGE Used for weighing of vehicles going and coming at site. G. SPRAYER PAGE 75 The arm’s length can be increased or decreased according to the width of the road. Used for spraying the tack coat and the prime coat. A heater is attached to the back of the vehicle so that the bitumen does not solidify. H. EXCAVATOR Used for digging of foundations and embankments. A drill bit can also be attached to the end of the arm in case of drilling operation. I. ROLLERS They are used for compaction and rolling operation. There are many types of rollers used in road construction. 1. Soil compactor 2. Tandem roller 3. Baby roller 4. Ptr roller 5. Static roller PAGE 76 Soil compactor – it can do both vibratory as well as plane rolling. The weight during plain rolling is around 6-9 tonnes and during vibrational rolling its around 9-15 tonnes. Tandem roller - A tandem roller is a piece of machinery used in paving roads and parking lots. Commonly referred to as a steam roller, the tandem roller is made up of two very heavy and unequal sized steel rollers fitted to a chassis, which is powered by steam, gasoline or diesel. The tandem roller is used to smooth out and compact asphalt or blacktop before it cools and hardens. The steel drums or rollers the machine rides on are often cooled with a stream of water in order to prevent the pavement from sticking to the rollers. PAGE 77 Baby rollers – they are used for compaction of the filler material in segmental retaining wall. PAGE 78 PTR rollers - - Once the paver finisher does its job the tandem rollers are used for further compaction. In the process the edges of the tandem compactor drums leave grooves or trailing lines on the otherwise smooth asphalt surface. These lines lead to uncomfortable and drifting drive. To overcome this, a pneumatic tyre roller is used which wipes out these lines or any other residual undulations and leave the road in good driving surface. Important feature - The last equipment in finishing the road surface is the Pneumatic Tyred Roller. - The Pneumatic Tyred Roller (PTR) is available from Volvo India. Mounted on 8 bold tyres with very heavy Ballast result in best road finish. PAGE 79 Static roller – for low compaction (road repair works of small size). J. GRADER A grader, also commonly referred to as a road grader, a blade, a maintainer, or a motor grader, is a construction machine with a long blade used to create a flat surface during the grading process. Typical models have three axles, with the engine and cab situated above the rear axles at one end of the vehicle and a third axle at the front end of the vehicle, with the blade in between. In certain countries, for example in Finland, almost every grader is equipped with a second blade that is placed in front of the front axle. Some construction personnel refer to the entire machine as "the blade." Capacities range from a blade width of 2.50 to 7.30 m and engines from 93–373 kW (125– 500 hp). Certain graders can operate multiple attachments, or be used for separate tasks like underground mining. In the construction of paved roads they are used to prepare the base course to create a wide flat surface for the asphalt to be placed on. Graders are also used to set native soil foundation pads to finish grade prior to the construction of large buildings. Graders can produce inclined surfaces, to give cant (camber) to roads. In some countries they are used to produce drainage ditches with shallow V-shaped PAGE 80 cross-sections on either side of highways. K. BITUMEN PLANT Here we can convert the grade of bitumen. A current of hot sir is passed from the pipes inserted in the tanks of bitumen. The air has the temp. of 220 o C. Vg 10 has more oil content than the higher grades, so the passing of hot air distils the mixture and oil gets separated. By controlling the amount of hot air different grades of bitumen can be obtained. L. JCB MACHINE This machine has a loader in front of it and excavator arm at back. Hence it can perform both the functions of loader and excavator but PAGE 81 on a smaller scale. A drill bit can also be attached at the place of excavator. M. PAVER A paver (paver finisher, asphalt finisher, paving machine) is a piece of construction equipment used to lay asphalt on roads, bridges, parking lots and other such places. It lays the asphalt flat and provides minor compaction before it is compacted by a roller. The asphalt is added from a dump truck or a material transfer unit into the paver's hopper. The conveyor then carries the asphalt from the hopper to the auger. The auger places a stockpile of material in front of the screed. The screed takes the stockpile of material and spreads it over the width of the road and provides initial compaction.[4] The paver should provide a smooth uniform surface behind the screed. In order to provide a smooth surface a free floating screen is used. It is towed at the end of a long arm which reduces the base topology effect on the final surface. The height of the screen is controlled by a number of factors including: the attack angle of the screed, weight and vibration of the screed, the material head and the towing force.[4] To conform to the elevation changes for the final grade of the road modern pavers use automatic screed controls, which generally control the screed's angle of attack from information gathered from a grade sensor. Additional controls are used to correct the slope, crown or superelevation of the finished pavement. PAGE 82 Paver laying BC Design of crust To design crust we have to have these parameters 1. Traffic load (unit is PCU {passenger car unit}, 1PCU = 8.1 tonne) 2. Loading on road (total weight exerted by layers) 3. Age upto which road has to be maintained. All these parameters are then changed to MSA. Then we need the CBR value of the road material. For egs. Take a stretch of road of 80 kms which have 2 sections CBR = 20 CBR = 10 PAGE 83 Then we can have two types of road crust With different thickness Same thickness for an avg. CBR value (15) which will be maintained for the entire length of 80 kms. From IRC 38 there is a graph of CBR and MSA which will give us the thickness of BM from which we can calculate thickness of other layers. The various layers of the road crust are BC DBM WMM GSB SG Embankment SDBC is never used for NHs, they are only used for SHs. BM is only used when we are constructing over existing roads. For new roads we use DBM. We are decreasing the use of BM as recent studies have indicated that they are the main cause of formation of pot holes. The different sizes of aggregates used in different layers 1. BC -- 20 mm 2. WMM – 53 mm 3. DBM – 45 mm 4. GSB – 75 mm STEPS IN CONSTRUCTION OF VARIOUS LAYERS 1. NGL – natural ground level. We determine this by auto level. The offset in longitudinal direction is 10 m & in horizontal its 2 m. PAGE 84 2. CNG – cleaning and grooving. Its removal of shrubs, roots & other unwanted materials. We remove shrubs and other organic matter because - If they decompose they will shrink and create a void space which will cause settlement of road. - They can grow and crack the road surface The general thickness of CNG is 150mm. 3. OGL – original ground level. Determined by auto level. Embankment formation After OGL we do testing for soils after every 1km, 2.5km, 5 km (depending on conditions) If CBR > 10 then we proceed for subgrade If CBR < 10 then we cut the embankment 4. FRL – finished road level. 5. GSB – granular sub base PAGE 85 There are 2 layers - Drainage layer - Filter layer If the soil have high strength then use only one layer ,ie, drainage layer If the soil is weak in strength then use both layers The GSB has higher density than WMM as it has to stop all the water. If water penetrates the GSB and reaches the SG layer which is purely soil then it will mix with it and form clay which will lead to settlement of road. Compaction of GSB 6. WMM- wet mix macadam It consists of 2 layers- - First layer – paver lay without sensor (but in practice we use grader). PAGE 86 - Top layer – paver lay with sensor. After WMM we clean the surface by groomer which is a mechanical broom which removes dust and other loose material from WMM After groomer we use air compressor to remove any remaining dust and fine material. it provides additional load distribution and contributes to the sub-surface drainage Compaction of WMM top layer 7. On WMM surface which is now clean and dry we do prime coat (SS). The WMM gets dry in 24-48 hrs. The rate of spraying PC is 6-9 liter/10 sqm. Since PC is slow setting we don’t do any work for 24 hrs. 8. After 24 hrs of applying PC we do DBM laying. PAGE 87 PAGE 88 9. After DBM laying we do tack coat (RS) and immediately after that we do BC laying. Rate of tack coat spray is 2.5-3 liter/10 sqm.. Minimum 5 km stretch is required for BC, because after rolling a stretch a hump is formed at the end of the stretch. So when we do the next stretch a uneven joint will be formed instead of a uniform one which will cause discomfort to the passengers. So to avoid it we cut a section upto the DBM level and along a dist. of 5m so as to match the end and the beginning of the stretches and avoid a hump formation. To cut the section we use a cutter or a hot knife. We first heat the road by a heater and then start cutting. The no. of joints along the entire road length should be as low as possible and the length of stretch is determined on the capacity of plants and width of the road. BC is done for every road. The functions and requirements of this layer are: - It provides characteristics such as friction, smoothness, drainage, etc. Also it will prevent the entrance of excessive quantities of surface water into the underlying base, sub-base and sub-grade, - It must be tough to resist the distortion under traffic and provide a smooth and skid- resistant riding surface, - It must be water proof to protect the entire base and sub- grade from the weakening effect of water. 10. After BC we do thermoplastic paint on the road. Center –10 cm Side edge – 15 cm Thickness – 2-2.5 mm CURVES There are 2 types of road curves S curve -- generally used in hilly regions PAGE 89 C curve -- generally used in plain regions MARKINGS Per 1 km – km stone Per 200m – hectometer stone (in 1 km there are 4 hectometer stones) SHOULDER – gives protection to DBM and BC. Rain and traffic will cut the sides of the layers. But when we provide shoulder, it itself gets cut and protects the layers. It’s also used to stand the vehicles to rest in case of emergency. OVER MOISTURE IN ANY LAYER If over moisture is there bumping will occur. Bumping is defined as sliding of road material form its place due to the reduced internal friction due to over moisture. So if bumping is present it can be removed by 2 ways:- (best one) remove the whole layer upto which over moisture is present. Throw away the material and put fresh one. Harrowing at least 4-5 times then mix again and relay if very high bumping is there we do sand filling. Generally done for clayey soils & high embankment. 1-3 m – low embankment 3-above – high embankment GENERAL THICKNESS OF VARIOUS LAYERS BC (single layer) 40mm DBM (single/multiple layers) 120-130mm (each layer of 60-65 mm) WMM (2 layers) 250mm (each layer of 125 mm) PAGE 90 GSB (single/multiple layers) 200mm SG ( 3 layers) top-150mm II – 150mm I-200mm ROLLING TEMPERATURES FOR DIFFERENT GRADE OF BITUMEN BITUMEN GRADE BITUMEN TEMP. AGGREGATE TEMP. MIXED MATERIAL TEMP. LAYING TEMP. ROLLING TEMP. Vg 40 160-170 160-175 160-170 150 min 100 min Vg 30 150-165 150-170 150-165 140 min 90 min Vg 20 145-165 145-170 140-165 135 min 85 min Vg 10 140-160 140-165 140-160 130 min 80 min WEATHER & SEASONAL LIMITATIONS IN LAYING Dense grade bitumen should not be laid 1. Presence of standing water on surface. 2. When rain is imminent & during fog, rains and dust storms 3. When base/binder course is damp 4. When speed of wind at any temperature exceed 40 km/ hr at 2m height. 5. When surface temperature is less than 10 o C PAGE 91 VARIOUS LAYERS FUNCTION: 1. SUBGRADE – it transfers load to earth mass. 2. GSB – it acts as a protection layer to SG. It doesn’t allow water to penetrate and disturb SG. 3. WMM – its function is to disperse the load over a larger area through a finite thickness and acts as a drainage to water because if WMM is not there then GSB will stop all the water, the bitumen from DBM will get strip 4. DBM – its function is to give strength and protect WMM layer and disperse load to a greater area. 5. BC – its wearing course. It doesn’t give any strength but is made for smooth riding & its called wearing course as it has to take up all the abrasive forces. PAGE 92 SURVEY PAGE 93 AUTO LEVEL SURVEY A dumpy level, builder's auto level, leveling instrument, or automatic level is an optical instrument used to establish or check points in the same horizontal plane. It is used in surveying and building to transfer, measure, or set horizontal levels. Operation - The level instrument is set up on a tripod and, depending on the type, either roughly or accurately set to a leveled condition using footscrews (levelling screws). The operator looks through the eyepiece of the telescope while an assistant holds a tape measure or graduated staff vertical at the point under measurement. The instrument and staff are used to gather and/or transfer elevations (levels) during site surveys or building construction. Measurement generally starts from a benchmark with known height determined by a previous survey, or an arbitrary point with an assumed height. Level checking is done for every layer B.S. + R.L. = H.I. H.I. + I.S. = R.L. B.S. back sight H.I. height of instrument I.S. intermediate sight R.L reduced level PAGE 94 TOTAL STATION A total station is an electronic/optical instrument used in modern surveying and building construction. The total station is an electronic theodolite (transit) integrated with an electronic distance meter (EDM) to read slope distances from the instrument to a particular point. Robotic total stations allow the operator to control the instrument from a distance via remote control. This eliminates the need for an assistant staff member as the operator holds the reflector and controls the total station from the observed point. COORDINATE MEASUREMENT - Coordinates of an unknown point relative to a known coordinate can be determined using the total station as long as a direct line of sight can be established between the two points. Angles and distances are measured from the total station to points under survey, and the coordinates (X, Y, and Z or easting, PAGE 95 northing and elevation) of surveyed points relative to the total station position are calculated using trigonometry and triangulation. To determine an absolute location a Total Station requires line of sight observations and must be set up over a known point or with line of sight to 2 or more points with known location. ANGLE MEASUREMENT - Most modern total station instruments measure angles by means of electro-optical scanning of extremely precise digital bar-codes etched on rotating glass cylinders or discs within the instrument. The best quality total stations are capable of measuring angles to 0.5 arc-second. Inexpensive "construction grade" total stations can generally measure angles to 5 or 10 arc-seconds DISTANCE MEASUREMENT - Measurement of distance is accomplished with a modulated microwave or infrared carrier signal, generated by a small solid-state emitter within the instrument's optical path, and reflected by a prism reflector or the object under survey. The modulation pattern in the returning signal is read and interpreted by the computer in the total station. The distance is determined by emitting and receiving multiple frequencies, and determining the integer number of wavelengths to the target for each frequency. Most total stations use purpose-built glass corner cube prism reflectors for the EDM signal. A typical total station can measure distances with an accuracy of about 1.5 millimeters (0.0049 ft) + 2 parts per million over a distance of up to 1,500 meters (4,900 ft) PAGE 96 PAGE 97 DOCUMENTATION PAGE 98 Registers 1. Receipt register – all the letters’ information, that are coming to the office are entered in this register. Every letter’s letter no, subject, sender’s name, receiver’s name, date of receiving is entered in the columns. 2. Dispatch register – all the letters’ information, that are sent from the office are entered in this register. Letter’s no. , subject, sender’s name, and receiver’s name is entered. Files 1. 1.1 File form head office (HO to TL) – all the letters that comes from the head office are put in this file PAGE 99 1.2 Files form site office (TL to HO) – a copy is made for each letter that TL sends to the HO and then O/C is marked on that copy and put in this file. 2. 2.1 File form Concessionaire office– all the letters that comes from the Concessionaire are put in this file 2.2 Files for Concessionaire office – a copy is made for each letter that TL sends to the Concessionaire and then O/C is marked on that copy and put in this file. 3. 3.1 File form Client office– all the letters that comes from the Concessionaire are put in this file 3.2 Files for Client office– a copy is made for each letter that TL sends to the Concessionaire and then O/C is marked on that copy and put in this file. Drawings All the drawings are made by Concessionaire and are then sent to the Independent engineer’s regional office which is then forwarded to the Head office where its gets checked by a competent authority, a concurred seal is stamped and is then send back to regional office which is then send back to the Concessionaire. Its only after this process the work can start. MPR Its called monthly progress report. Here all the work done till the month is mentioned and a copy is sent to each of the following persons PAGE 100 1. TL 2. Project director 3. Project manager PAGE 101 Sample of work progress report PAGE 102