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1 Prof Syed Sabihuddin Department of Civil Engineering PRMCEAM,Badnera 1.

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1 1 Prof Syed Sabihuddin Department of Civil Engineering PRMCEAM,Badnera 1

2 2  General: Potable water supply system is installed in city, towns, villages for domestic and other purposes. Municipality, Municipal Corporation and other authorities are responsible for public water supply system. Certain quality standards of drinking /potable water have been laid down by various National and International authorities. These standards are adopted in India. Physical and Chemical standards are stated vide Annexure I (Refer Text Book). Guide line Values for Bacteriological Quality have been stated vide Annexure II (Refer Text Book). Sources of water depends on economic availability, population to be served etc. This may be river, stream, spring, tube-well, open dug well, lake etc. For large population it is required to install water treatment plant. There are many types of plant which depends on total requirement of potable water in the city/town. In case tube-wells are installed for supplying potable water in small town areas then it may be possible to make simple treatment like chlorination, before supplying. 2

3  Water supply system may be divided in two groups, (a) Distribution System (b) Collection/Conveying raw water from sources to treatment plants. It may be possible to construct large Dams across river/stream and store water in large reservoir. Raw water is brought at filtration plant near city/town through conveyance main. Treatment of water depends on quality of raw water, total quantity of supply required for the city/town. Regular testing of raw water will also reveal the quality of drinking water, determination of the source of contamination.  In the laboratory physical, chemical, bacteriological, biological tests are carried out. Physical tests determine the aesthetic quality of drinking water. Chemical tests determine chemical impurities which may affect the quality of water and indicate the type and extent of pollution of the raw water. Bacteriological tests determine the bacterial content in raw water. Biological examinations are done to determine information on causes of objectionable tastes and odours in water or clogging of filters and indication of remedial procedure and extent. 3

4  Examination of Water Samples: The test reports will guide the water supply engineers to decide:  Trends in the quality of drinking water with the passage of time.  It will help in the improvement/maintenance of public health.  Finally the concerned staff shall be able to identify the source of contamination (if any) including in the network of distribution system and within premises of public. Water samples are collected for bacteriological, chemical, physical and biological tests.  Bacteriological analysis is important and it will reveal the presence and type of bacteria in water, and will also indicate extent of treatment or other solution to make the water suitable. Biological test will reveal the odours and if any objectionable matter is found in the drinking water. Sometimes the biological impurities will clog (choke) the filtration system. 4

5  Sample collection: The sample should be representative of water to be tested and they should be collected with utmost care to ensure that no contamination occurs at the time of collection or prior to examination/testing in the laboratory. The sample bottle should not be opened till the time of filling. The stopper with the cap should be removed with care to eliminate soiling. During sampling, the stopper and the neck of bottle should not be touched by hand. The bottle should not be filled completely but sufficient space is left for shaking before analysis. Then the brown paper wrapping should be tied to protect sample from contamination. Samples should be collected in containers of Pyrex glass or other inert materials like polythene etc. Sample bottles are required to be cleaned before use. Possibility of breaking is less in case of polythene bottle. 5

6  Sample System: In order to make the treatment effective a suitable sampling system has to be adopted. In the laboratory the samples should be provided with information like date, time of collection, source (with place/location), temperature of water, time of collection, address of premises etc. The samples for bacteriological tests must be collected first (to avoid likely escape from subsequent samples). Samples, if collected far away from the laboratory, they should be transported to the laboratory duly packed in wooden/metal/plastic/heavy board boxes with separate compartment for each bottle. All samples of water should be properly labeled with necessary descriptive data for identification and likely use. Care should be taken to avoid contamination of the sample by any surface scum. 6

7  Sampling for Physical and Chemical Analysis: About 2.5 litres of the sample is required for chemical, physical and biological analysis. The sample bottle should be rinsed 2 or 3 times before filling with the sample to be analysed. The sample should be transported to the laboratory as quickly as possible. If it takes more than 24 hours then special arrangement (like ice-box) is to be made. Certain parameters like, temperature, pH, dissolved gases may change significantly during transport. Hot samples should be cooled. Samples from wells should be collected only after the water from the well has been pumped for some time to ensure that the sample will be truly representative of ground water.  Sampling for Bacteriological Analysis: Sterilized glass bottles, provided with ground glass stopper having an overlapping rim should be used. 7

8  Sampling from Taps: Tap should be opened fully for 2 to 3 minutes or for a sufficient time clearing of the service line. Then the bottle should be filled with sample water. Leaking taps which allow water to flow over the outer surface of the bottle must be avoided at sampling points. The leak should be attended to before sampling. It should be ascertained whether the tap from where the water sample collected is supplying water from a service pipe directly connected with the main or with a cistern or a storage tank, this information should be sent along with the sample.  Size of Sample: The volume of the samples collected for testing in the laboratory should be greater than 250 ml. Testing should be done within an hour of collection of the samples, but it should not exceed 24 hours. It may be noted that sample is not for bacteriological examination. 8

9  Frequency of Sampling: The frequency of collection of samples for chemical analysis depends on the variance of the quantity of tested water, the types of the treatment process adopted and other local conditions. In general, for systematic chemical examination, the samples should be collected at least once in every three months from supplies serving for more than 50,000 persons.  It is necessary to collect samples of both raw and treated water for examining toxic substances at least every 3 months and more frequently when tolerance levels of toxic substances are known. For bacteriological sampling, frequency of sampling and location of sampling points at pumping stations, treatment plants, reservoir and booster pumping stations, as well as distribution system, should be such as to enable a proper evaluation of the bacteriological quality of the entire water supply. 9

10  The sample should be taken from different points on each occasion to enable over all assessment.  In the event of epidemic or immediate danger of pollution, it should be borne in mind that much more frequent bacteriological examination will be required.  For biological examination, where seasonal growth of plantation is known to be a regular occurrence, sample may need to be taken at short intervals. When growth of plantation is not anticipated, samples should be drawn monthly or on less frequent basis.  Minimum Frequencies for Sampling: 10 Population ServedMinimum No. of samples to be taken from entire distribution system. Upto 20,000One Sample per 5000 of population per month. More than 1,00,00One Sample for 10,000 of population per month.

11  Parameters of water: Colour: Colour in water may result from the presence of natural metallic ions (Fe & Mn) humus and peat materials, plantations, weeds and industrial wastes. Colour may be in two forms i.e. (a) true colour — The colour of water from which the turbidity has been removed and (b) aparent colour, - which may be due to dissolved compounds. But may also be due to suspended matter.  Odour: Odour like taste, depends on content of a stimulating substance, with the appropriate receptor cell. In its pure form, water cannot produce odour or taste sensation. Odour is recognized as a quality, affecting acceptability of drinking water. Most organic and inorganic chemicals, contribute taste, odour. These chemicals can originate from municipal and industrial waste water, from natural sources such as decomposition of vegetable matter.  Suspended solids: Total ions includes dissolved materials. Dissolved salts are good for healthy water life but high concentration can cause imbalance. 11

12  Chemical Parameters:  pH Value: Water is the product of chemical composition of Hydrogen ions and Hydroxyl ions. Pure drinking water is supposed to contain equal number of these ions and is considered neutral with pH = 7 i.e. neither acidic nor alkaline. If the sample is having more ‘H’ ions, it has pH less than 7 and so recorded as acidic. If ‘OH’ ions are more, then it is recorded as alkaline with pH value greater than 7. “A healthy drinking water should have pH value between 6.5-8.5”.  Chlorides: Chlorides are one of the major inorganic ions present in water and waste water. Natural water generally contains chloride ions, due to dissolution of salt deposits, discharge of effect from industries, irrigation and drainage. In potable water, the salty taste produced by chloride concentration is variable. Chlorides are not strictly pollutants, but concentration above 1,000 mg/L may harm agricultural crops and corrode the metallic pipes. 12

13  Hardness of water: It is a general term used to indicate the capacity of water to produce lather with soap. Hardness of water is caused by ‘Calcium and Magnesium ions’. It forms scales when used in boilers. Its content makes water practically unsuitable for use in laundry and domestic purpose. Hardness of natural water may normally range from 10 to 100 mg/L in terms of CaC0 3.  Iron: Discharges from industries of iron/steel/forging units etc. pollute the water with high iron contents, Ground water, some times have high concentration of iron. If iron content in water supply is high, it will cause staining of clothes and utensils. High amount of iron in water will give a reddish and turbid appearance.  Bacteriological Parameter: Total Coli Form: Bacteria cause a number of diseases. Pathogenic analysis is very tedious. The coliform are a group of bacteria. Coliforms are easily detectable in water by less time consuming method. The drinking water should be free from coliform. “The coliform bacteria - must not be detectable in a 100 ml. sample”. 13

14  Standard Tests:  Physical Examination: The parameters tested are temperature, turbidity, colour, taste and odour.  Chemical Examination: (1)This includes tests of consistency and characteristics of water that affect the health of the consumers and the potability of water, viz pH, acidity, alkalinity, hardness, Ca, Mg, Fe, Mn, Cu, Zn, Al, Sulphates, Fluorides, Chlorides, Nitrates, total dissolved and suspended solids. (2)Tests of efficiency of treatment i.e. Chlorine demand (free and combine), residual Chlorine, coagulant and dosage. (3)Tests for chemical parameters which are indication of pollution such as total Nitrogen and Nitrogen in various forms like NH 3, N0 2, dissolved Oxygen and BOD (Biological Oxygen Demand). (4)Tests for toxic chemical substance : Lead, Arsenic, Mercury, Pesticides. (5)Tests for radioactivity.  Bacteriological Examination: Microscopic tests for identification. 14

15  Criteria for Acceptance of Tests: Detailed lists of various tests are under following groups:-  (1)Physical and Chemical standards, (2)Toxic Materials  (3)Radioactivity, (4)Bacteriological quality  Various tests are as per Manual of Water Supply and Treatment as Published by Central Public Health and Environment Engineering Organization (CPHEEO), Ministry of Urban Development, Govt, of India, New Delhi. Names of tests (indicating characteristics, acceptable test results with unit/value which are cause of rejection.) If the value is not as per acceptable criteria but the same is not category of cause of rejection then various factors, circumstances, extra time allowed for using such water etc. are to be considered and necessary decision/direction is to be given by the higher authority. The figures under column “Acceptable” are the limits upto which is generally acceptable to the consumers. 15

16  Figures in excess of those mentioned under “Acceptable” render the water not acceptable, but still may be tolerated in the absence of alternative and better source but up to the limits indicated under column “cause for Rejection” above which the supply will have to be rejected.  There are over 31 tests as per afore said Water Supply Manual vide Annexure I. Tests of water are carried out at different stages of water supply engineering works, for different purposes and from different sources. During pre-construction stages water samples are collected from various raw water sources viz. river, large surface reservoir, streams, underground water source. The tests are carried out for deciding type of treatment to be done, techno-economic feasibility of water treatment. At this feasibility and detailed planning stages most of the tests as per tables given at (Annexure I) are carried out. After treatment, water samples are taken at the point of supply/inlet of distribution system. 16

17  At initial stage or before commissioning the project/water supply system most of the tests as stated in the aforesaid tables are carried out. After full satisfaction at this stage it is not required to carry out all these 31 tests daily at outlet/supply system of treatment plant. During operation of the water supply system and supplying treated potable water to the consumers/public, samples are collected daily from distribution network and taps of consumer premises. Decision is taken to carry out certain essential/important tests daily from the aforesaid collected samples. Some other tests should be carried out once in a month or every 3 months and certain tests may be earned out once in a year. In case of tube wells certain tests should be carried out at least at initial stage (i.e. after boring and before installing pipes etc.), as per test results final decision is taken about installing and commissioning the tube well. 17

18  If certain important test results (viz, hardness value, pH value, E- coli bacteriological tests) are not acceptable the tube well should be abandoned for drinking water purpose. Problem in respect of Fluoride & Arsenic is found in certain areas of some states. Arsenic has been found in 7 districts of West Bengal. Hence special care and tests of Arsenic are to be taken in such areas. It is not required to carry out such tests daily in other areas. Hence detailed study is to be carried out on various tests (30 tests) at initial stages of the project i.e. before commissioning the project and supplying potable water to public. On the basis of this study, programme is made about carrying out various tests stating frequency. It has been found many water supply laboratory collect samples daily from various locations of distribution networks and consumers’ premises and following tests are carried out:- 18

19  (a)Essential tests: (1)Bacteriological: Coliform Organisms, E- Coli, Plate Count. If these test results are beyond acceptable limit then water supply should be stopped on urgent basis.  (2)Physical tests: Taste, Odour and Turbidity.  (3)Chemical Tests: Total hardness, Iron, Chloride, Residual Free Chlorine (Which should be 0.2 minimum; this test is very important). Range of pH value should be 6.5-8.5.  (b)There are certain desirable tests and the same are to be selected and decided about its frequency.  (c)Tube Well, Shallow Well: To reduce virus risks for drinking water following treatments should be done :-  Disinfection and filtration & disinfection. 19

20  Facilities in the laboratory: The working benches/tables should be of a height of 0.75 m to 1.0 m with acid resisting tops. Adequate gas, electric power and water points must be provided along the benches and services for gas, electricity and water, can be fitted against the walls, under the bench, thus, providing unobstructed floor space throughout. There should be ample sink and drain lines. The analytical work in the laboratory requires provision of ample window space and fluorescent artificial lighting.  Equipment: The equipment in the laboratory must be adequate to permit proper analytical laboratory control of purification process. Careful planning is necessary while equipping the laboratory to affect proper utilization of the equipment. Proper maintenance of the equipment and storage of chemicals must be in the hands of responsible analyst. 20

21  A need based planning to acquire consumable materials like glass ware, chemicals and reagent is in general more important than the procurement of various special equipment. Calibrated instruments should frequently be checked using standards.  Laboratory accreditation is formal recognition of the technical competence of a laboratory including of quality system management, which is based upon the third party assessment. Throughout the world, accreditation is based on the international guide known as “ISO IEC guide 25”. There are two types of laboratories:-  Testing Laboratory  Calibration Laboratory  All the laboratories should be accredited with National Accreditation Board for Testing and Calibration Laboratory (NABL), Ministry of Science & Technology, Govt, of India. 21

22  Records: A continuing programme of examination of water and controlling quality to determine its conformity with established water quality standards calls for proper maintenance of accurate and complete records. These records are essential for review of the working of the water treatment equipment/filtration plant and also for efficient operation and maintenance works. Various records (maintenance of registers on proper forms, issue test reports on proper forms, correspondences etc.) are to be maintained. Monitoring, auditing of laboratory operation/system are to be carried out periodically. Records are to be maintained for these purposes. Technical records are very important. Analysis of sampling of water, test reports are to be done on the basis of various methods. 22

23  Staff for water laboratories  Following staff of suitable numbers are required  Water Analyst  Water Analyst (Chemist)  Water Analyst (Bacteriologist)  Laboratory Technicians  Clerk  Sample Takers  Laboratory Cleaners  Engineers having experience in Water Supply particularly testing  Operators  Laboratory Asst.  Helpers 23

24  General: Organisation setup in respect of Highway project is little different than building construction projects. The department engages a Consultant for preparing DPR (Detailed Project Report). DPR is comprehensive important documents. Detailed field survey, investigation, design of drawings, detailed estimates, Specifications, BOQ etc. are prepared. Tests of samples of soil, murum, stone/aggregate, sand and traffic survey are carried out. Design is done as per IRC codes, specification book of MORTH. These documents are part of Quality Assurance Plans of the project. These basic principles/system of quality assurance plan are also applicable in other construction works. Consultant is to get DPR approved from the competent authority of department. Consultant set up their field laboratory, field survey agencies, traffic survey team etc. The department may also engage consultant for supervising quality of works. 24

25  Material Engineer, Asst. Material Engineer, Laboratory Technicians, road design engineer, specialized design engineer etc. are engaged by the Main consultant. Their site offices are set up at project site for supervising quality of work.  Consultant prepare plans for Quality Assurance System and to be got approved by the Chief Engineer of department. The contractor’s part of this QMS (Quality Management System) process is referred as Quality Control (QC) while the Construction Supervision Consultant’s part of the procedure is referred as Quality Assurance (QA). The contractor is responsible to deploy competent personnel to perform quality control as “Quality Control Action Plan.” The objective evidences of all tests, checks and inspections carried out from time to time are documented in prescribed formats for reference and record. There are many formats for maintaining these records in the computer, registers, statements, files. 25

26  Quality Audit: Quality Audit is a managerial tool used for reviewing the whole or a part of the quality system by internal or external agencies. Quality Audit is defined to be a systematic study and examination of documents related to quality control during construction phase. Quality Audit may also be carried out in respect of design works carried out by the consultants.  General Philosophy: Quality control alone in itself does not guarantee durability and uniform performance during its service life in case of a design deficiency unless and until it gets identified and rectified during construction. In case, it goes unnoticed then product does not perform as envisaged in the design. In fact, reliability of a Quality Assurance plan lies in its implementation not only in the initial stages of work but during all relevant stages including maintenance which alone will ensure a durable and functional product over the design life as envisaged in the design document. 26

27  The periodic checks during construction process are carried out as laid down in the contract documents, the codes and specifications (including specifications book published by the MOST, Govt, of India) mentioned there in both by the Contractor and Construction Supervision Consultants. The application of these activities would nearly assure a quality product at the end.  Quality Cycle: The quality cycle stands with quality control measures prior to actual construction activities, runs during construction stage and quality audit of the results achieved, identification of defects and establishments of their causes. It ends with suggestions of remedial measures, their execution and ensures their implementation against recurrence of the defects. Analysis of problem is carried out by the Supervision Consultant and to give remedial measures and ensure implementation of remedial measures. 27

28  List of Major stages of Project:  Inception meeting to discuss standards, codes, extent of survey & field investigation-Administrative approval of Preliminary Project Estimate.  Appointment of experienced Consultant and preparation of DPR after carrying out field survey and technical investigation, Tests, BOQ, design & drawings, specifications, Technical Sanction etc.- Approval by Chief Engineers.  Preparation of Draft Tender documents by the consultant and inviting tender and acceptance of contractor’s offer.  Consultant and Contractor are to take action for mobilization of manpower, labour, machinery, to set up site laboratory, documentation on prescribed formats. Preparation of Checklists of Construction works. 28

29  Work satisfactorily completed, issue of inspection note by the Consultant and department’s engineer, maintenance of various document on prescribed formats in computer, registers, files including monitoring meetings, minutes, inspection notes etc.  Recording executed items of works as per Specifications in Measurement Books (MB) jointly (by Contractor, Consultant/Department’s engineer)  Stages at Serial Nos. 1 to 3 relate to Q.A. and Stages at Serial Nos. 4 to 6 relate to Q. C.  Contractor’s Activities Related to Quality: As per contract- agreement provision the contractor is to ensure that all actions are taken as per Quality Assurance in the “planning” and “execution” of works. Contractor shall give a trial run of the equipment, plants/machinery to achieve the laid down specifications and “tolerance”. He shall ensure that all his testing 29

30  equipments are calibrated periodically/once in every three months. The setting out will include establishment of benchmarks, control line pegs, marker/reference pillars, by using precision instruments like total station (instead of theodolite), auto levels. Quality Control plans are to be got approved from the department.  Pre-construction checks like checking form work, setting field laboratories, camber board, super elevation board, survey instruments, laboratory instruments for carrying out various tests as per BIS codes, IRC codes and Specification book of MORTH, Quality Handbook of IRC etc. Pre-construction activities are absolutely vital for achieving quality, dimensions control.  Contractor’s Quality Control Action Plan: A few main items/activities of Contractor in respect of quality are stated as under. 30

31  (1)“Quality Control Plan” is defined as the programme and “documentation” of that programme developed by the contractor and approved by the Engineer-in-Charge/Project Engineer/ Team Leader of the Consultant. This addresses the actions, inspection, sampling and testing as per test method stipulated in the codes of BIS/IRC. This will keep production and placement operation in control. Where an operation goes out of control it is required to correct the situation and bring it back into control.  (2)Include identification of the quality control personnel, their qualifications and practical experience, the laboratories and its equipments/instruments which will be used by the contractor and project consultant appointed by the department.  (3)Document the contractor’s policy for ensuring quality and assignment of Quality Control accountability and responsibility. Department will engage one Quality Control Manager who will check quality control of contractor, sub­contractors, producers and suppliers. Control charts should be displayed at Site Office. 31

32  (4)Quality Control Plan prepared by the contractors is binding on him as well as sub-contractor, suppliers. Contractor should obtain quality control plan for “sublet work” from his sub- contractor and make it part of his quality plan.  (5)The organization chart will identify all quality control staff by name and function and will indicate total staff required to implement all elements of the quality control program including inspection, sampling and testing for all production processes and placement.  (6)The quality control plan should also indicate the individual who will be acting as the coordinator between the contractor/ subcontractor and the outside organization/independent laboratory. 32

33  Check Lists: The activities during various stages of construction works need effective supervision for ensuring specification. For better supervision and quality control the checklists of various items/stages of work should be prepared. These checklists are useful for all engineers and contractors.  Documentations: Maintenance of records in respect of various tests in proper forms is important. Contractors and Quality Control Consultant are required to maintain these records. Senior engineers of Contractors, Quality Control Consultant and department are required to carry out test checking.  Dimensional Control: “The dimensional control is an essential part of quality control.” The level of the formation, sub-grade layers, other layers shall not vary those calculated with reference to the longitudinal and cross profile of the road/highway shown on the drawings. There are prescribed tolerances of various items of works (viz. sub-grade, sub-base, base layers, wearing course etc.) 33

34  Measurements/checking of surface levels of pavement layers are taken at grid of points placed at 6.25 m longitudinally and 3.5 m transversely for two lane highways.  Surface Regularity of Pavement Courses  The longitudinal profile shall be checked with a 3 m long straight edge/moving straight edge at the middle of each traffic lane along the line parallel to the centre line of the road. Maximum permitted number of surface irregularities is laid down in the specification. This test is very important because riding quality of road surface depends on this test. Road users are very much concerned on riding quality for comfortable travel. 34

35  General: Following three types of roads are considered:  Highway, City Town Roads & Hilly/Mountainous Roads: These roads are constructed in two stages viz. (i) planning stage including field survey, technical investigation and designing, awarding work to contractor. The second stage is construction activities. It is required to check and test existing earth, materials etc. for preparing Detailed Project Report (DPR). Generally the department engage consultant for preparing DPR. Consultant deploy engineers for checking quality of survey and levels for preparing long sections and cross sections of existing and proposed highway. Consultant is required to setup field laboratory for carrying out certain tests. During construction period the department, consultant and contractor are required to check quality and to carry out various tests and checking for ensuring constructions as per specifications, codes of BIS and IRC. 35

36  Many design criteria and procedures have been laid down in the codes of “Specifications for Road and Bridge Works” published by the Ministry of Roads Transport & Highways, Govt, of India. Here only a few items of quality control and checking will be considered. Quality control/checking in respect of preparation of DPR which include survey, levels, field tests of materials, sub- grade, stone, murum, designing proposed road structures, gradients, curves, super-elevation, pavement (crust), drainage etc. are to be done.  It is required to check the field laboratories set up at different locations during preparation of DPR and construction of roads. Testing equipments are to be checked. Quality control work is to be done as per aforesaid specification book. Consultant and contractor shall carry out quality control tests of materials and work at frequency stipulated in the aforesaid specification book. 36

37  For testing of samples of soils/soil mixes, granular materials and mixes, bituminous materials and mixes, aggregates, and form shall be arranged. Certain materials like, RCC/Pre-stressed Hume Pipes, Steel etc. are to be tested at the manufacturer’s plant or at approved laboratory. Various tests and checking are to be carried out as per Handbook of Quality Control for construction of Roads (IRC: SP - II), relevant BIS codes and relevant clauses of specifications. Method of sampling and testing of materials shall be as per Handbook (IRC: SP - II).  Testing of CBR value, Bankel Beam Deflection test, Traffic volume, Axle load in MSA (Million Standard Test):- These tests are to be carried out during preparation of DPR/design of road structure. Excavation of pits of required depth is done for testing existing sub-grade soil for ascertaining CBR value. Traffic volume and Axle load in MSA are found out by carrying out field traffic survey as per IRC code. It is required to make pit (size 1m x 1m x depth of sub-grade level) at the edge of carriageway (partly on carriageway and partly on shoulder). This test of CBR values are found out (soaked/unsoaked) as per IRC code. 37

38  Bankel Beam Deflection (BBD) test is also carried out on existing pavement as per IRC:81 to know the necessity of extra thickness/ overlay/strengthening work. Then designing of road crust/ pavement is carried out as per IRC code (No. 81). BBD test is carried out at every alternate Km. in order to assess the residual structural strength of flexible pavement.  Super Elevation: It is essential to calculate degree/quantum of super elevation at all curves as per IRC code. Super Elevation of required quantity is to be provided during construction at different stages i.e. sub-grade, sub-base, base course (WBM) and bituminous courses. Template for checking super­elevation is required. It has been found that template is not generally available at site. It is also required to check transition curves at both ends of curves; super-elevation is also provided gradually along the transition curve. 38

39  WBM (Water Bound Macadam): There are three types of WBM courses :- Grade-I-90 to 45mm, Grade-II-63-45mm & Grade-III-53- 22.4mm  Grading of aggregate/Sieve sizes are given in Table 14.1, 14.2, 14.3, 14.4, 14.5 and 14.6. It is required to check this grading of aggregates by collecting samples from site. Thickness of Grade-II and III should not be more than 75 mm thick each layer. If total thickness of base course is more than 150 mm thick then Grade-I course is also to be laid. 39

40 40

41  Testing of Binding Material for WBM: Binding material (mooram as per specification) is to be spread at the time of wet rolling of WBM course. Binding material having a Plasticity Index (PI) value less than 6 should be used. Testing of this material is to be carried out in the laboratory as per IS: 2720 (Part - 5). But this is not done in city/town road works. Quantity of binding material will depend on type of screenings. Using of malba or earth in WBM is highly objectionable. This has to be tested for Plasticity Index and value should be less than 6. Generally P.I. test of binding material is not carried out in city/town road construction. This requirement should be complied to achieve quality of work. 41

42  CBR Test for Granular Sub-base (GSB)/Drainage Layer: AS per aforesaid Specifications book and IRC code it is required to lay one drainage layer just below the bottom of base layer (i.e. WBM/Wet Mix Macadam); this course is known as GSB. CBR tests are to be performed on specimens re-moulded at field dry density and moisture content for the quality of materials. Minimum CBR value should be 30 for Grade - I, 25 for Grade - II and 20 for Grade III of GSB. It is important to supervise the operation of GSB layer carefully as per aforesaid specifications book.  Accurate Projected Traffic and designing Road Width: It is required to check quality of design work carefully. As per IRC code (IRC : 73-1980) it is required to carry out traffic survey along various reaches of road. Formation width and carriageway width are to be designed considering certain period for working out the projected traffic (Which may vary to 20/40/50 years); the “design traffic” means expected traffic on the road in the “design year”. 42

43  As per IRC code it is required to work out Traffic Volume in MSA. Construction period is to be added on stated design period. Carriageway width may be intermediate lane 5.5 metre width/2-lane width 7 metre/4 lane width/4 lane divided carriageway. This is done on the basis of total projected traffic volume in PCU (Passenger Car Unit) of all types of vehicles. Details in respect of design of pavement are available in IRC Code (No. 37-2001). For the purpose of designing total crust thickness of pavement it is required to decide “design life” of road. Above stated particulars are required to check and to carry out certain field tests during carrying out field survey and investigation for preparing DPR. It is also required to check by consultant’s surveyor/engineer to check surveying and level works at field side by side as per IRC code (No. IRC : SP - 19) Closing of level at the end of day by fly level on reverse direction should be done to know the error. As per specification book / IRC code it is required to provide minimum cushion of 0.60 metre (excluding thickness of road crust). 43

44  Check List: Detailed Check List of various items of works should be prepared for proper supervision, testing and random checking of construction works. One check list is given here as example:  Check List for Granular Sub-base:  Pre-Construction Stage: Confirm, that the sub-grade is adequately compacted. If there is a time gap for execution of GSB layer and the previously finished sub-grade, check whether the sub-grade test results are valid? Check, whether the compaction of the sub-grade is still in good condition? and, if not, carry out rolling. Clear all loose or external materials, before laying GSB from sub-grade top.  Confirm, that the camber, cross slope and side slope of embankment are correct. Check, whether the sub­grade top surface tolerance of levels are within the permissible limit. 44

45  Confirm, that the grading of GSB materials has been tested, and is of correct specifications.  Check whenever the “Ten Percent Fines Value” test and water absorption value test have been conducted and the results are as per the Specification.  Check templates available for indicating thickness of loose layer to be spread.  Check, if watering arrangements are adequate.  Confirm, if rollers are available and that they are in working order.  Construction Stage: Observe the spreading and compacting operations. Ensure, that the material is being spread without significant segregation. If necessary, obtain samples from the material being spread and conduct sieve analysis test. Check the layer thickness, and confirm, that it is as per specification requirements. 45

46  Check, that the layer of loose material is as specified in the specification. (For moisture content - IS : 2720 Part 2).  Check that the layer of compacted layer is as specified.  Check, density of compacted layer is as specified. (Density 98% according to IS : 2720 Part 8).  Observe the compacting operation to determine that the material forms a firm, stable base throughout the spread width.  Post Construction Stage: Tolerances are specified in IRC Code/Specification book.  Checklist for Bituminous Layers using Mechanised Construction, BM (Bituminous Macadam), DBM (Dense Bituminous Macadam), BC (Bituminous Concrete), SDC (Semi Dense Concrete): A detailed list of various checking points as per specification book should be prepared under following parts  (1)General 46

47  (2)Plant Operation  Pre-construction Stage  Production Stage  Transportation Stage  Bitumen Distributor  During Laying  During Trial Compaction  During Rolling  Typical Corrective Action Plan for Asphaltic layers Placement.  Quality Control Tests during Construction: For ensuring the requisite quality of construction, the materials and works shall be subjected to quality control tests. Test procedures for various quality control tests are available in the specification book. 47

48  Test on Earthwork for Embankment, Sub-grade Construction and Cut Formation:  (a) Burrow material : Grid the burrow area at 25 m c/c.  Following tests on samples of earth shall be carried out :-  Sand Content - IS:2720 (Part -4) 2 Test per 3000 cum of soil.  Plasticity Test- IS:2720 (Part-5) Each type to be tested, 2 tests per 3000 cum of soil.  Density Test - IS:2720 (Part -3) Each soil type to be tested, 2 tests per 3000 cum of soil.  Deleterious Content Test - IS:2720 (Part-27) As & when required.  CBR Test on Moisture Content Test - IS:2720 (Part-2), One test for every 200 cum of soil.  Materials to be incorporated in the sub-grade on soaked/ unsoaked samples as per IS:2720 (Part-16). One CBR test for every 300 cum. 48

49  Compaction Control: Control shall be exercised on each layer taking at least one measurement of density for each 1000 square metres of compacted area. The determination of density shall be in accordance with IS:2720 (Part-28).  Flow Chart of Quality Assurance: As example one “Quality Assurance Flow Chart” for controlling bituminous pavement Quality is given below: (Figure - 14.1) 49

50  Documentation of Measures Taken for Q.C.:  Documentation of Quality Tests, Check Lists, Record Notes of Inspections, Quality Flow Charts, Summary of Test Reports, Test Procedures/Test Method are to be made properly. Test methods have been stated in various BIS/IRC codes and specification book.  It is important to prepare documents for above stated matters. These records are to be test checked by senior engineers of department, consultant and contractors independently by carrying test of materials, completed/finished works. Proper formats are to be prepared for above stated matters, various tests of raw materials, manufactured material and tests for completed items of work, finished road surface, culverts, bridges etc.  Reference of BIS code number, IRC code number, specification book of MORTH etc. are also to be given on the format/statement/register. 50

51 51  Solve any two questions.  Write in brief about examination of water samples and standard tests.  Discuss about criteria for acceptance of tests and essential tests.  Write short note on Contractor’s Activities Related to Quality and Contractor’s Quality Control Action Plan  Discuss in detail quality control tests and checking of road sector.


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