Selasa, Mei 21, 2013

RUIDP GOVT. OF RAJASTHAN RAJASTHAN URBAN INFRASTRUCTURE DEVELOPMENT PROJECT HAND BOOK FOR ROAD WORKS Project Management Unit (PMU) RUIDP Avs Building, Jawahar Circle , Malviya Nagar, Jaipur- 17 Hand Book For Road Works Hand Book For Road Works TABLE OF CONTENTS ROAD CLASSIFICATION........................................................................................................ 1 1.1Non-urban Roads:: .................................................................................................................. 1 1.2Urban Roads: Urban roads are classified into the following five categories: ......................... 1 2PLANNING AND DESIGN ....................................................................................................... 2 2.1Road Network Planning/Traffic Master Plan .......................................................................... 2 2.2Design Criteria and materials .................................................................................................. 4 2.2.1Road Work ...................................................................................................................... 4 2.2.2Culverts: -........................................................................................................................ 8 3CONSTRUCTION ...................................................................................................................... 9 3.1Preliminaries ........................................................................................................................... 9 3.1.1General: ........................................................................................................................... 9 3.1.2Alignment & Bench Mark............................................................................................. 10 3.1.3Materials, Labour and equipment ................................................................................. 10 3.1.4Safety measures ............................................................................................................ 10 3.1.5Arrangement for traffic during construction ................................................................. 10 3.1.6Construction programme............................................................................................... 10 3.2Environment Protection ........................................................................................................ 10 3.3Setting Out ............................................................................................................................ 11 3.4Clearing and Grubbing .......................................................................................................... 11 3.5Drainage ................................................................................................................................ 12 3.6Earth Work ............................................................................................................................ 12 3.6.1Road way & Drainage Excavation ................................................................................ 12 3.6.2Blasting ......................................................................................................................... 12 3.6.3Pre-splitting technique .................................................................................................. 13 3.6.4Preparation of cut formation ......................................................................................... 13 3.6.5Excavation for structures .............................................................................................. 14 3.6.6Borrow excavation ........................................................................................................ 14 3.6.7Embankment construction............................................................................................. 14 3.6.8Embankment under special conditions: ........................................................................ 15 3.6.9Surface / Subsurface drains ........................................................................................... 17 3.7Sub-bases and Bases (Non-Bituminous) ............................................................................... 17 3.7.1Granular sub-base ......................................................................................................... 17 3.7.2Water Bound macadam ................................................................................................. 18 3.7.3Wet mix macadam: ....................................................................................................... 22 3.8Bitumen Bound Bases and Surfacing.................................................................................... 24 3.8.1General requirement:..................................................................................................... 24 3.8.2Prime Coat .................................................................................................................... 24 3.8.3Tack-Coat:..................................................................................................................... 24 3.8.4Bituminous Macadam and Dense Graded Bituminous Macadam ................................ 25 3.8.5Bituminous Concrete and Semi Dense Bituminous Concrete ....................................... 28 3.8.6Open-graded premix surfacing...................................................................................... 32 3.8.7Open graded premix surfacing using cationic bitumen emulsion ................................. 33 3.8.8Close graded premix surfacing/mixed seal surfacing: .................................................. 34 3.8.9Seal coat – ..................................................................................................................... 35 3.9Concrete Sub-Bases/Bases .................................................................................................... 36 3.9.1Dry lean concrete sub-base ........................................................................................... 36 3.9.2Concrete base: ............................................................................................................... 38 3.9.3Joints: ............................................................................................................................ 38 3.9.4Equipment of proportioning and laying ........................................................................ 40 3.10 Geo synthetics: ...................................................................................................................... 41 3.11 Quality Control for Road Works ........................................................................................... 42 3.11.1General guideline for Quality Control for Road Works................................................ 42 4TRAFFIC CONTROL DEVICES ........................................................................................... 46 4.1Traffic Signs.......................................................................................................................... 46 1 Hand Book For Road Works 4.1.1General .......................................................................................................................... 46 4.1.2Classification of Sign .................................................................................................... 46 4.1.3Sizes of Sign ................................................................................................................. 46 4.1.4Retro-Reflective signs: .................................................................................................. 47 4.1.5Shape: ............................................................................................................................ 47 4.1.6Colours : ........................................................................................................................ 47 4.1.7Urban locations: ............................................................................................................ 47 4.1.8Mandatory/regulatory signs: ........................................................................................ 47 4.1.9Cautionary/warning signs: ............................................................................................ 47 4.1.10Informatory signs: ......................................................................................................... 48 4.1.11Guidelines on use of retro-reflective sheetings for road signs ...................................... 49 4.1.12Colour Scheme .............................................................................................................. 49 4.2Road Markings ...................................................................................................................... 49 4.2.1General .......................................................................................................................... 49 4.2.2Types of carriageway marking lines ............................................................................. 49 4.2.3Materials and colours .................................................................................................... 50 4.3Centre lines and lane lining:.................................................................................................. 52 4.4No overtaking zones: ............................................................................................................ 52 4.5Road Delineator ................................................................................................................... 53 4.5.1General .......................................................................................................................... 53 4.5.2Roadway indicators ....................................................................................................... 53 4.5.3Hazard Markers: ............................................................................................................ 53 4.5.4Object Markers:............................................................................................................. 53 4.5.5Boundary Stones ........................................................................................................... 53 4.6Traffic Control Lighting Devices .......................................................................................... 55 4.6.1Junction ......................................................................................................................... 56 4.6.2Roundabouts ................................................................................................................. 59 5COMMON TESTS ON MATERIALS AND WORKS .......................................................... 60 5.1Determination of Moisture Content of Soils (IS: 2720 Pt. II)............................................... 60 5.2Liquid Limit and Plastic Limit (IS: 2720 Pt. V) ................................................................... 60 5.3Moisture-Density Relationship (IS: 2720, parts VII & VIII) ................................................ 60 5.4Laboratory CBR (IS: 2720, part XVI) .................................................................................. 60 5.5Flakiness and Elongation Indices (IS: 2386, part I) .............................................................. 61 5.6Field CBR (IS:2720, Pt. XXXI) ............................................................................................ 61 5.7In-situ Density by Sand Replacement Method (IS: 2720, Pt. XXVIII) ................................ 61 5.8Aggregate Impact Value (IS: 2386, part IV) ......................................................................... 61 5.9Bitumen Penetration Test (IS: 1203) .................................................................................... 62 5.10 Marshall Stability Test (ASTN: D 1559) .............................................................................. 62 5.11 Stripping Value (IS: 6241) .................................................................................................... 62 5.12 Tray Test for Control of Rate of Spread of Binder (IRC:SP:11) ......................................... 62 5.13 Tray Test Rate of Spread of Grit in Surface Dressing (IRC: SP:11) .................................... 62 5.14 Binder Content of Paving Mixtures by Centrifuge (IRC:SP:11) .......................................... 62 5.15 Checking Surface Regularity Using a Straight-Edge (IRC: SP: 11) ..................................... 63 5.16 Water Sensitivity of Bituminous Mixes (ASTMD 1075-88) ................................................ 63 5.17 Sand Equivalent Test (IS: 2720, Part XXXVII).................................................................... 63 5.18 Soundness Test (15:2386, Part-V) ........................................................................................ 64 5.19 Los Angeles Abrasion Test (IS: 2386, Part-IV) .................................................................... 64 5.20 Swell Test.............................................................................................................................. 64 5.21 Water Absorption Test (15:2386, Part III) ............................................................................ 65 5.22 Determination of Polished Stone Value (BS: 812, Part 114-1989)....................................... 65 Hand Book For Road Works GENERAL INFORMATION 1 1.1 1) Road Classification Non-urban Roads: Non-urban roads in the country are classified into six categories: Expressways: The function of expressways is to cater for movement of heavy volumes of motor traffic at high speeds. They connect major points of traffic generation and are intended to serve trips of medium and long length between large residential areas, industrial or commercial concentrations and the central business district. They are divided highways with high standards of geometrics and full or partial control of access and provided generally with grade separation at intersections. Parking, loading and unloading of goods and passengers and pedestrian traffic are not permitted on these highways. National Highways: These are main highways running through the length and breadth of the country connection major ports, highways of neighbouring countries, State capitals, large industrial and tourist centres etc. State Highways: These are main arterial routes of a state linking district headquarters and important cities within the state and connecting them with National Highways of the neighbouring states. Major District Roads: These are important roads within a district serving areas of production and markets, and connecting these with each other or with the main highways. Other District Roads: These are roads serving rural areas of production and providing them with outlet to market centres, taluka/tehsil headquarters, block development headquarters or other main roads. Village Roads: These are roads connecting villages or group of villages with each other and to the nearest road of a higher category. Urban Roads: Urban roads are classified into the following five categories: Expressways: The function of expressways is the same whether the traverse through urban areas or non-urban areas. Arterial Streets: This system of streets, along with expressways where they exist, serves as the principal network for through traffic flows. Significant intra-urban travel, such as, between central business district and outlying residential areas or between major suburban 'centres takes place on this system. These streets may generally be spaced at less than 1.5 km in highly developed central business areas and at 8 km or more in sparsely developed urban fringes. The arterial streets are generally divided highways with full or partial access. Parking, loading and unloading activities are usually restricted and regulated. Pedestrians are allowed to cross only at intersections. Sub-arterial Streets: These are functionally similar to arterial streets but with somewhat lower level of travel mobility. Their spacing may vary from about 0.5 km in the central business district to 3 - 5 km in the sub-urban fringes. 2) 3) 4) 5) 6) 1.2 1) 2) 3) RUIDP Jaipur 1 Hand Book For Road Works 4) Collector Streets: The function of collector streets is to collect traffic from local streets and feed it to the arterial and sub-arterial streets or vice versa. These may be located in residential neighbourhoods, business areas and industrial areas. Normally, full access is allowed on these streets from abutting properties. There are few parking restrictions except during the peak hours. Local Streets: These are intended primarily to provide access to abutting properly and normally do not carry large volumes of traffic. Majority of trips in urban areas originate from or terminate on these streets. Local streets may be residential, commercial or industrial, depending on the predominant use of the adjoining land. They allow unrestricted parking and pedestrian movements. 5) Table No. 1.1 Terrain Classification S.No. Terrain Classification Percent cross slope of the country 1 2 3 4 Plain Rolling Mountainous Steep 0-10 >10-25 >25-60 >60 2 2.1 1) Planning and Design Road Network Planning/Traffic Master Plan The Road & Bridge works should be properly integrated with the ongoing schemes / sub-project of urban environment improvement project (i.e. Water supply, Sewerage, Drainage etc.) under RUSDIP. The detailed Project report shall be prepared as per the IRC Guidelines. The existing road network system of the city should be taken into account for preparation of traffic master plan for 30years design period i.e. year 2041 and accordingly the proposed improvement scheme shall be planned. The following, activities have to be worked out for preparation of traffic master plan. • • • • • Mid block traffic survey for different roads including parking survey, pedestrian survey Traffic survey in junctions including pedestrian movement Analysis of traffic survey data Fixation of Planning Horizon Collection of important features, socio economic data, right of way etc. and Proposed Traffic Plan of the city to avoid traffic congestion in peak hours including safety of traffic, provision of parking, safe movement of Pedestrian & slow moving vehicles etc. Any development/expansion plan, tourism etc. shall also be taken into consideration for preparation of traffic master plan Projection of proposed traffic RUIDP Jaipur 2 2) • • Hand Book For Road Works • Improvement schemes i.e. new road, widening of existing road, signaling system, parking facilities, footpath, foot over bridge, Sub-way, ROB, RUB, Bridges etc have to be finalized in line with the traffic masterplan. Proposed improvement schemes shall be limited to existing right of way or minimum acquisition. Preparation of guidelines for passing of utilities considering the minimum damage/ obstruction of road for lying of new utilities & maintenance ofutilities. • • 3) 4) 5) The Socio- Economic structure of the city shall be taken into consideration for future prospects of the city as well as needs for development. Based on Traffic & Socio-Economic analysis, the priority list of improvement scheme shall be prepared to suit the traffic master plan. From the above priority list of improvement. Scheme, the different works shall be phased for .10/20/30 years for smooth traffic flow as well as minimum Environmental hazards. Immediate improvement scheme shall be selected to implement as per their merits and budgetary allocation. The proposed improvement scheme shall be integrated with proposed works under RUSDIP. Based on selection criteria for works under RUSDIP after studying their Feasibility, RUSDIP intends to take up the works of ROB/RUB/high level Bridges as the priority to this sector. In RUSDIP, it is proposed that only very important / priority roads should be considered in accordance to tentative allocation/identified list of works of the town. In general, the construction of road shall be started after completion of works related to sewerage, drainage, water supply etc. for the stretches of the road. As and when roads getting damaged due to sewerage works; road restoration in complete width should be taken under the sewerage packages; whereas, for water supply works the road restoration may be limited to the width of excavation only. Longitudinal Sections and Cross-Sections • • Levels along the final centre line should be taken at all staked stations and at all breaks in the ground. Cross-sections should be generally taken at 50 - 100 metre intervals in plain terrain and 50 - 75 metre in rolling terrain depending on the nature of work. Preferred distance for existing roads and built-up situations is 50 m. The interval should be still less in hilly terrain, about 20 m. In additition, cross- sections should be taken at points of beginning and end of spiral transition curves, at the beginning, middle and end of circular curves, and at other critical locations. All cross-sections should be with reference to the final centre line, extend normally up to the right-of-way limit, and show levels at every 2 - 5 metre intervals and all breaks in the profile. Centre line profile should normally be continued at least 200 metres beyond the limits of the project. This is intended to ensure proper connecting grades at both ends. With the same objective, profile along all intersecting roads should be measured upto a distance of about 150 metre. Further, at railway level RUIDP Jaipur 3 6) 7) 8) • Hand Book For Road Works crossings, the level of the top of the rails, and in the case of subways, the level of the roof should be noted. On existing roads, levels should be taken at all points of intersection in order to help the final fixation of profile. • While finalizing road, top level of man holes constructed for sewer line and water line should be considered. If it is not possible to flush the road with top of Manholes then raising of level of these manholes should be accounted for in estimation. For new roads utility duct along road should be prosed in the city area to pass water, power and other lines Proper Plantation on both side of roads should be considered. Typical Longitudinal Sections and Cross-Sections appended on Appendix-1 • • • 2.2 2.2.1 1) Design Criteria and materials Road Work The Specifications for road works are based on the currents Indian Roads Congress Specifications and recommended codes of practice, and ministry of Roads Transport and highways as per IRC specifications. Roads shall be planned for full width of Right of Way (ROW) available. In general, space for utility services / utility corridor may be identified separately in accordance to the future requirements so that the obstruction of road & damage of the pavement shall not be occurred in future. If separate space for utility is not available, a suitable planning for passing of utilities has to be prepared for laying of new utilities & maintenance of utilities. In general, the road pavement is designed for 20 years design period. However, to minimize the initial cost, 10-15 years design period may be adopted for design of road pavement and overlay of BC & DBM for every 5 years shall be recommended for remaining design period. For this case, cost effective study shall be carried out for all cases with proper analysis. In absence of actual traffic growth by suitable method, the annual growth rate of traffic may be adopted as 7.5 percent. The reconnaissance survey of the existing roads should be carried out. All available information of the existing road i.e. year of construction, sub grade CBR, soil characteristics pavement composition and specifications, traffic, pavement performance, overlay history, climatic conditions, location of underground & over ground utilities etc. should also be collected from field visit and line agency i.e. from PWD, PHED, ULB's etc. Land Acquisition plan for approved improvement proposal shall be prepared based on collected revenue map & information. Normally median should not be less than 1.2 m except critical locations and this should usually be unpaved in four or more than four lane carriageway except specific cases due to the width of the right of way limitation. Flexible pavement for new roads should be designed in accordance with IRC: 37- 2001. Strengthening requirements either by method provided in IRC: 37- 2001 or the Benkelman Beam Deflection Technique described in IRC: 81-2001. RUIDP Jaipur 4 2) 3) 4) 5) 6) 7) Hand Book For Road Works 8) 9) 10) For the purpose of structural design only the number of commercial vehicle of weight of 3 tones or more and their axle loading is considered. Profile correction should be avoided as far as possible. If it is not possible to avoid then it should be taken bare minimum. Effort should be made to have useful cost effective designs. Quality of works is more dependent on adhering to design parameters during construction rather than higher design specification. BC and DBM layers should be bare minimum and it should be designed with the provision of overlay in future. Bitumen of Grade 60/70 or Crumb Rubber Modified (CRM) ~5hall be used for all bituminous work except for mastic asphalt for which 85/25 Grade of Bitumen or CRM shall be used. Rigid pavement should be proposed where carriageway comes in submerges and low lying area. The design shall be done in accordance with IRC Standard No.58. Table No. 2.1 Design speeds km/h Road Class NH & SH Ruling Minimum MDR Ruling Minimum ODR Ruling Minimum VR Ruling Minimum Plain 100 80 80 65 65 50 50 40 Rolling 80 65 65 50 50 40 40 35 Mountainous 50 40 40 30 30 25 25 20 Steep 40 30 30 20 25 20 25 20 11) 12) 1. 2. 3. 4. Table No. 2.2 Widths in plain (for National and State Highways) Item Plain and Terrain Open areas Land width (metre) Normal Range Building lines (overall width, metres) Rolling Built-up areas Mountainous and steep terrain Open areasBuilt-up areas 1. 2. 45 30-60 80 302420 30-60 Distance between building line and road boundary (set- back) should be 3-6 metres 3. 4. Notes: • Control lines (Overall150 width, metres) Roadwaywidth Single-lane (metres)Two-lane For other road categories, see IRC: 73. -12.0* -12.0 6.25** 8.80** RUIDP Jaipur 5 Hand Book For Road Works • • • • • * Reduce to 9 m for SHs having remote possibility of widening to 2-lanes. ** Widths are exclusive of parapets (0.6 m) and side drains (0.6 m). In hard rock stretches and unstable locations, the roadway width may be reduced by 0.8 m on two- lane roads and 0.4 m in other cases. However, where such stretches occur in continuous long length on single-lane roads, reduction in roadway width should not be effected unless requisite passing places are provided. Passing places where provided should be based on actual needs, generally at the rate of 2-3 per km. These should be 3.75 m wide, 30 m long on the inside edge (i.e., towards the carriageway side) and 20 m long on the farther side. On horizontal curves in mountainous and steep terrain, increase roadway equal to extra widening of carriageway. For multi-lane highways, the roadway should provide for the requisite number of traffic lanes plus shoulders and median. The shoulder width should in general be 2.5 m. Desirable median width for rural highways is 5 m while the absolute minimum is 1.2 m. The following geometric Standard for roads and culverts shall be adopted: Table 2.3: geometric Standard 13) S. No. 1. 2. 3. 4. 5. 6. 7. 8. Design Parameters For NH 2-Lane road 80-100 30-60 2x3.5 1.5 1.0 4-lane road 80-100 60 4x3.5 1.5 1.0 7.5 to 5.5 4.5 to 1.2 1.5 For SH & City road 60-80 20-60 3.5m x no. of lanes As per requirement of' project (Min 1.0) 1.0 7.5 to 5.5 4.5 to 0.6 1.5 Design Speed (kmpH) Right of Way(m) Width of Carriageway (m) Width of Paved Shoulder(m) Width of Unpaved Shoulder(m) Width of service Road (m)7.5 to 5.5 Median Width (m)- Minimum width of footpath in 1.5 meter Width of roadside parking (m) Width of Bus bay (m) Camber (%) of B.T. Surface Sight distance (m) a. Stopping Sight distance b.Intermediate Sight distance c. Safe Stopping Sight distance Maximum Super elevation (%) E=V2/225 R Minimum Radius (m) 9. 10. 11. 12 No provision 4.54.5 2.0-2.52.0-2.5 20-180 40-360 250 4.0 20-180 40-360 250 4.0 3.0 to 2.5 4.5-3.0 2.0-2.5 20-180 40-360 250 4.0 13. 14. Minimum curve length should be 150 meters for 5o deflection angle and increase or decrease at the rate of 30 m for 1o SpeedPlain &Hilly & snow bound Km/ hrRolling Terrain RUIDP Jaipur 6 Hand Book For Road Works S. No. Design Parameters 35 40 50 65 80 100 12 For NH 45 60 90 155 230 360 15 15. 16. 17. 18. 19. 20. 21. 22. 23. Minimum turning radius (m) at junction Length of Transition CurveMin. Length of Transition Curve >(i) Ls.= 0.0215V3/CR or (ii) Ls.= 2.7V2/R Where V=speed in Km/hr C=80/(75+V) subjected to Max.0.8 and min 0.5 Extra width (m)As per table 12 & clause 10.6 of IRC:86 Maximum0.6 -1.5 Vertical gradient in general (%)2.52.52.5 Maximum vertical gradient (%)3.333.334.0 Minimum Length of Vertical606060 Curve (m) Kerb height (m)0.2250.2250.225 Lateral Clearance (m)0.5-1.00.5-1.00.5-1.0 Vertical Clearance at under pass5.55.5 5.5 Urban Areas (m) For SH & City road 45 60 90 - - - 10 . Note: In general, above parameters shall be applicable for new alignment However, the above design standard may be modified suitably considering ground reality / space constraint prior to approval of RUSDIP / concerned department. In case of proposals for cement concrete roads under the slum areas or narrow width lanes, which are not subjected to regular heavy traffic may be kept with 100 mm thick M20 grade concrete finished surface on 100 mm thick M10 grade concrete. 14) 15) Thermo-plastic paints should be used for road marking. Roadside drain should be designed as per IRC Standard. The intensity of rainfall should be taken from the realistic past data. The design calculation for the intensity should be furnished in details along with adopted design procedure. Shifting of utility services should be avoided as far as possible. In case it is not avoidable then effort should be made to minimize the cost by taking minimum required shifting of utilities. Environment & Social impact assessment shall be done to minimize environment & social hazards. Spacing of street light should be designed in accordance to the required width to be illuminate and accordingly capacity of luminaries and height of poles should be decided. Dark patches shall not been seen on the road surface. 16) 17) 18) RUIDP Jaipur 7 Hand Book For Road Works 19) 20) 21) 22) 2.2.2 1) Use of mechanical Grader for construction of embankment, sub-grade and sub base shall be mandatory. For WMM all the material used shall be crusher broken. Bituminous layers shall be laid by paver finisher. Bitumen of Grade 60/70 or CRM shall be used for all bituminous work. Thermoplastic paint conforming to MORTH specification CL: 803 shall be used. Traffic signs, Bollards, Hazard markers, Raised pavement markers shall conform to relevant IRC specification and provision should be kept in BOQ. Culverts: - Proper sub soil investigation should be done in advance before preparation of Bid Documents. The investigation for the foundation should be got done and enclosed and clear recommendations of the SBC for the type of foundation proposed should be given. At least one Bore hole should be made at any abutment location. The copy of this report should be enclosed with the tender document. The contractor shall verify the subsoil investigation report at the site before bidding the tender. The levels should generally follow the absolute levels by picking up the reference level from Survey of India Bench Mark or some other established bench mark. The levels should also be checked with base maps being prepared under RUSDIP. In general, the minimum design period for culverts is 50 years. In general, RCC Box (single/multiple cell) with curtain wall of sufficient depth shall be adopted for new/ extension of culverts. Box shall be placed over Bed level. For small drainage, pipe culvert with 900mm (min) diameter NP-4 Pipe shall be provided. The work pertaining to sub structures and superstructures shall conform to guideline given under Clauses 2200 and 2300 respectively of MORTH Specification (Fourth Revision). Requirement of structural concrete shall conform to Clause 1700. Steel Reinforcement (un-tensioned): Only TMT steel reinforcement (un tensioned) conforming to clause 1600 of MORTH specification from original billet manufactures shall be used for all the component of culverts. Materials: Materials for structures shall conform to Clause 1000 of MORTH Specifications (Fourth Revision). 2) 3) 4) 5) RUIDP Jaipur 8 Hand Book For Road Works Table No. 2.4 Data to be collected for Culverts A. NEW CULVERTS 1. Catchments area: Marking the watershed on topo sheet and measuring the area, or for smaller catchments finding the watershed by compass survey, or for flat terrain by conducting a local contour survey to demarcate the watershed. Cross-sections: Three cross-sections, one at selected site, one at upstream and one at downstream. Longitudinal section: Should show bed levels, L.W.L. and H.F.L. Maximum H.F.L. : Observation of marks left by flood, local enquiry and comparing with data for any nearby structure. Velocity observations: Observed during actual flood. Trial pits: Dug upto firm ground. Engineering characteristics of soil and safe bearing capacity at foundation level. B. EXISTING CULVERTS Type of structure and details of span, vent height-width of roadway, etc. Load carrying capacity. Condition of foundation, sub-structure and super-structure. Signs of silting/scouring, blockage, overtopping, etc. H.F.L., deck level, adequacy of waterway, etc. 2. 3. 4. 5. 6. 1. 2. 3. 4. 5. 3 3.1 3.1.1 1) Construction Preliminaries General: Study in depth the contract drawings, contract conditions and special conditions, specifications, special provisions, the technical note issued by the sanctioning authority, the estimate of quantities, etc. to have a clear understanding of the scope and extent of the project. Check whether the project involves permission or approval of other departments/agencies, e.g., approval for cutting of trees or relocation of utility services, etc.* • Location of trees, if required to be planted and other landscaping features may also be decided and got approved from the competent authority. Take action to get all these done even prior to award of contract. Look into the stipulated contract time for completion vis-à-vis the working seasons and calendar months to ensure that the tasks are completed according to the specified programme. For this purpose, modern project management techniques should be used. 2) • RUIDP Jaipur 9 Hand Book For Road Works Keep at site: • • • • • • 3.1.2 Survey and investigation report including material test results. Bill of quantities. Site order book; Work diaries Quality control record book; A set of working drawings mounted on cloth and Up-to-date construction programme Alignment & Bench Mark Have a check on final centre line of stakes, pillars or hubs and replace the missing one. Check the bench mark for levels, and tally these with those given on the drawing Materials, Labour and equipment List out the materials and their quantities which will be provided by the Department. Similarly, do the exercise for equipment. Take action to procure these for supply in time. Ascertain from the contractor the sources from where he will bring the material for the project, number of labour to be employed and facilities for housing, sanitation, transport, fuel wood and first aid to be provided for them. Details of site laboratory should also be obtained. Ensure that necessary repair facilities, spares, stores and POL are available at site. Safety measures Ascertain from the contractor, the measures he proposes to take for safety of workmen including purchase of insurance policies, and ensure that these satisfy the rules and regulations in force. "Guidelines on safety in Road Construction Zones" (IRC: SP: 55) may be referred for further details. Arrangement for traffic during construction Proper arrangement for traffic during construction over part width of roadway is to be as per site condition. The temporary diversion may be adopted / constructed where the duration of work is expected to be long and traffic is heavy Construction programme Review construction programme given in the project report and see whether it is possible to adhere to this in the light of availability of resources and related factors. If not, prepare a revised programme to reflect the actual situation and revised cost, where necessary' and submit to higher authorities with justification, for approval. The programme should be based on critical Path Method (see IRC: SP-l4 for details) for major works and in the form of bar charts for other cases. Environment Protection All precautions should be taken for safeguarding the environment during the course of construction. The following points need special attention: 3.1.3 1) 2) 3) 3.1.4 3.1.5 3.1.6 3.2 1) Borrow pits should not be dug in the right-to-way of the road. RUIDP Jaipur 10 Hand Book For Road Works 2) 3) During construction, soil erosion should be fully controlled and sedimentation and pollution of natural water courses, ponds, tanks and reservoirs should be avoided. Bituminous hot mix plant and concrete batching plants should be located away from habitation and industrial establishments. All precautions shall be taken to minimise the levels of noise, vibration, dust and emissions from these plants. No material shall be used or generated, during construction, which is hazardous to the health of human beings, animals or vegetation. Nuclear gauges shall be used only after ensuring their safe use in accordance with the regulations in force. All reasonable steps shall be taken to minimise dust nuisance during the construction. All existing highways and roads used by vehicles supplying material or plant should be kept clean and clear of dust, mud or other extraneous materials. Setting Out All construction should be with reference to the final centre line of the main location survey. The centre line should be accurately referenced every 50 m interval in plain and rolling terrains, 20 m intervals in hilly terrains and at all curve points, by marker pegs and chainage boards set in or near the fence line. The schedule of reference dimensions should be prepared and marker pegs shall be maintained till the end of the work. Working bench marks tied with the reference bench mark should be established at the rate of four numbers per km and also at or near all drainage structures, other bridge and underpasses. An up to-date record of all bench marks should be maintained and the working bench marks should be checked frequently. On construction reaching the formation level stage, the centre line should again be set out and accurately referenced by marker pegs at the outer limits of the formation posts of timber or steel should be kept one meter from the formation edges showing the finished formation/finished base course/finished road levels. It should be possible to stretch a thread across to verify the finished levels of various courses. All survey monuments, bench marks, beacons, etc. should be maintained accurately during the construction process. A survey file containing the setting out data for traverse points and levels shall be prepared and maintained during the construction process. Precision automatic levels, having a standard deviation or + 2 mm per km and fitted with micrometer attachment shall be used for all double run levelling work. Setting out of the road alignment and measurement of angles shall be done by using theodolite with traversing target, having a accuracy of one second. Measurement of distances shall be done preferably using precision instruments, like, distomat. Clearing and Grubbing Demarcate the limits of clearing and grubbing as shown on the drawings. 4) 5) 6) 7) 3.3 1) 2) 3) 4) 5) 6) 3.4 1) RUIDP Jaipur 11 Hand Book For Road Works 2) Mark the roadside trees, shrubs, buildings, utility lines, etc. which are not to be disturbed and ensure that the contractor provides suitable safeguards to protect these from injury or damage. Before start of work, examine the contractor's work plan including the procedures to be followed for disposal of waste materials and the precautions proposed against soil erosion, air pollution and water pollution. All trees, stumps, etc. falling within excavation and fill lines should be cut to such depth below ground level that in no case these fall within 500 mm of the sub grade. Also, all vegetation (roots, undergrowth grass, etc.) and other deleterious matters should be removed between fill lines. From embankment/cut areas, remove and store top soil for reapplication later. Have the removed materials of value suitably stacked for reuse or auctioning. Burning should not be permitted in wooden areas. Periodically observe the operations to ensure that damage to adjacent property is being prevented and tree, utilities and structure are being preserved. Drainage The site engineer should have a clear understanding that performance of a road is closely related to drainage, both surface and subsurface. The sources of water involved may be the surface runoff, seepage flow through subterranean channels, ground water movement and moisture transfer within the soil masses, etc. and surplus water should be removed away from the roadway area quickly and effectively. 3) 4) 5) 6) 7) 8) 3.5 3.6 Earth Work Ensure that the specified cross fall for both pavement and shoulder is provided right from sub grade level and maintained during the earth work and ensure that sub grade is sufficiently above the HFL/ ground water table or the natural ground level and should have minimum height o.6 m. 3.6.1 1) Road way & Drainage Excavation The area for the roadway & drainage excavation should be cleared and grabbed. Set out the limit of excavation to the line & levels. Providing of control pegs for alignments fixation and embankment construction are to be done as per relevant clause of Ministry’s specification. During excavation different grades of materials may be met, best material should be reserve for use in the top 0.5 m height of the embankment. Excavated material which is useable in pavement construction should be stacked, proper measurements and recorded in proper manner. Blasting Points needing specific attention are: Blasting operation should be carried out in presence of a competent and experienced supervisor. RUIDP Jaipur 12 2) 3) 3.6.2 1) Hand Book For Road Works 2) 3) 4) 5) Blasting should be carried out in fixed hours which have been made known to people in the vicinity. Red flags should be prominently displayed in all directions. If blasting is within 50 m of any railway track, concerned Railway Authority should be notified of the blasting schedule, well in advance. The magazine for the storage of explosives should be located at approved site and built to the specifications of the explosive department. The magazine should have an effective lightening conductor. All necessary precautions as required by explosive Act should be taken. The type of explosives and the plan of drilling and firing should be carefully examined for suitability. The over-burden should be removed and measurements taken before blasting operation is started. Specified procedures should be strictly followed in case of misfire. Maintenance of day-to-day account of explosives. Pre-splitting technique This blasting technique is defined as the establishment of a specified excavation slope in rock by controlled use of explosives and blasting in properly aligned and spaced drill holes- This technique is recommended for harder rock types. This consists of drilling a series of closely spaced parallel holes (not exceeding 900 mm centre-to-centre) that reasonably conforms to the desired outlines and grade. Production holes should be drilled at least 2.5 m away from the pre-split plane. The pre-split holes are charged and fired prior to the production holes. This provides for a pre-shared face for the primary blast. All over-burden soil and weathered rock along the top of the excavation, for a distance of 5 m to 15 m beyond the drilling line, should be removed before drilling the pre-splitting holes. Normally, this technique should first be applied to short test section to see whether the method has produced acceptable slope without undue shatter. Any blasting technique which results in damage to the pre split surface should be discontinued. Preparation of cut formation Cut formation requires very close inspection for the reason that it is for the first time that the material gets exposed. Check for suitability of the natural material. Some shales may look hard- when dry but get slushy in presence of water. If such unsuitable materials are met with, have these removed to a depth of at least 0.5 m or as otherwise specified and replaced with suitable material. If density of sub-grade is lower than 97 per cent of the laboratory density determined as per IS: 2720 (Part VIII), it shall be loosened to a depth of 500 mm, watered and re RUIDP Jaipur 13 6) 7) 8) 9) 3.6.3 1) 2) 3) 4) 5) 3.6.4 1) 2) 3) Hand Book For Road Works compacted in 250 mm thick loose layers to a density not less than 97 per cent of the maximum laboratory dry density. 4) In rock formation all dish shaped cavities left out by blasting should be cut out at edges to facilitate drainage. Low areas should be filled up with sub-base material and properly compacted. Any seepage should be intercepted and properly drained. Excavation for structures The points which require specific attention are : Setting out true to specified lines and levels. Strength and safety of all temporary shoring, bracing and other earth supporting devices. Normally, open foundation should be laid dry. Dewatering by boiling, pumping, diversion channels and other necessary work should be carried out when seepage flow is met with. The discharged water should not cause damage to the works, crops or property. Detailed examination of the stratum at the foundation level to see whether the soil fits in with the design assumptions, or the material is unsuitable to be left in place. 5) 3.6.5 1) 2) 3) 4) 5) 3.6.6 Borrow excavation 3.6.6.1 General Guideline for Borrow excavation 1) When earth available from the excavation for the roadway formation and drainage excavation falls short of the requirement of embankment construction in the remaining reaches, this should be obtained from approved area(s) outside the land width identified for the purpose. Check for the location, size and depth of borrow pits, where payment is on the basis of borrow measurements, have cross-sections, taken of the area and leave deadmen or cross ridges. The volume of borrow excavation and of compacted embankment will be different if there is variation in the respective dry densities. For example, if the in-situ DBD of borrow soil is 1.6 gm/cc, and that of embankment 1.8 gm/cc, the quantity of borrow excavation will be larger by 1.8/1.6 times. On completion of all measurements for payment, have the borrow pits opened out partly at either ends to facilitate easy drainage. 2) 3) 4) 3.6.7 Embankment construction 3.6.7.1 General Guideline for Embankment construction 1) The stability of an embankment depends upon the foundation, the use of suitable materials, proper placing and compacting of thematerials and strict adherence to quality control measures. The suitability of embankment material is shown in Table 3.1. Table 3.2 indicates the compaction requirements. RUIDP Jaipur 14 Hand Book For Road Works 2) 3) After cleaning and grubbing, the sub grade level should be compacted at least 97 % Proctor Density of determined laboratory Proctor Density as per IS-2720 (Part VIII). Clods or hard lumps of earth should be broke down and embankment and sub grade material should be spread in layer of uniform thickness not exceeding 200 mm compacted thickness over entire width Table 3.1. Suitability of embankment materials S. No. 1. 2. 3. Type of Work Maximum laboratory dry unit weight when tested as per IS: 2720 (Part VIII) Embankment upto 3 mts. height, not Not less than 15.2 kN/cu.m subjected to extensive flooding Embankment exceeding 3 mts. height or Not less than 17.5 kN/cu.m embankment of any height subject to long periods of inundations Sub grade and earthen shoulders /vergesNot less than 17.5 kN/cu.m /backfill Table 3.2. Compaction requirement for embankment and sub grade S. No. 1. 2. 3. Type of Work Sub grade and earthen shoulders Embankment Expansive Clays Relative compaction as percentage of maximum laboratory dry density as per IS:2720 (Part VIII) Not less than 97 Not less than 95 a) Sub grade and 500 mm portion just below the sub grade b) Remaining portion of embankment Note: 1. Not allowed Not less than 90 2. Ordinarily, the materials satisfying density requirements, given above should be employed for construction of embankment and sub grade. The density requirements are not applicable to light weight materials, e.g., cinder, fly ash, etc. The material to be used in sub grade should also satisfy design CBR values. It should preferably have a CBR more than 5 per cent. Material with CBR less than 5 per cent shall not be used in sub-grade. 3.6.8 1) 2) Embankment under special conditions: Widening existing embankment or construction against sloping ground End dumping of materials from trucks on widened portions should be avoided as far as possible. If existing side slopes are steeper than 4: 1, cut horizontal benches 0.3 m wide to ensure bond. If the slopes are 4:1 or flatter, the surface may be roughened by ploughing or scarifying. RUIDP Jaipur 15 Hand Book For Road Works 3) For wet conditions benches with slightly inward fall and sub-soil drains at the lowest point shall be provided before the fill is placed against slopping ground. 3.6.8.1 Earthwork over existing road surface: If within 1m of the new sub grade level, scarify to a depth of 50 mm or more if specified, if the road surface is BT, and completely removed, if of cement concrete. If the level difference is more than one m, allow the existing road surface to stay. 3.6.8.2 Embankment around structures: 1) Suspend filling around structures upto a distance of twice the height of the embankment. Permit filling only after the concrete/masonry has been in position for at least 14 days. Bring up the embankment in equal horizontal layers simultaneously on each side to avoid undue thrust and unequal pressure. The material used for backfill should not be an organic soil or highly plastic clay, plasticity index and liquid limit should not be greater than 20 and 40 respectively. 2) 3.6.8.3 Embankment construction under water: Only acceptable granular material or rock should be used for filing-under water. The material should consist of graded hard durable particles of size not exceeding 75 mm. This material should be non-plastic having uniformity co-efficient of not less than 10. 3.6.8.4 Earthwork high embankment: 1) Earthwork for high embankment should be carried out by stage construction of fills at controlled rates of filling. The embankment should be surcharged for the specified period. At the stage of formation level, surcharge where used material should be removed. High embankment should remain in place for the required settlement period before excavating footings for structures, like, abutment wing wall, etc. 2) 3.6.8.5 General Guideline for Construction of rock fill embankment: 1) In normal circumstances embankment should not be constructed with rock fill aterial. Rock fill should not be used at least for a depth of 500 mm below the formation level. This should be made up of earthen cushion. The rock fill should be hard durable and inert material capable of being deposited in layers. Argillaceous rocks (clay, shale’s, etc.), un burnt colliery stock, and chalk should not be used in rock fill. The material for rock fill should not exceed 300 mm in size and percentage finer than 125 mm should not exceed 10. The material shall be spread and levelled in layers. Each layer should be compacted by five passes of vibratory roller (8-10 tonnes). : The compacted thickness of each layer should not exceed 500 mm. Before laying the next layer, the surface voids RUIDP Jaipur 16 2) 3) 4) 5) Hand Book For Road Works should be filled with broken fragments. The top layer of rock fill should be thoroughly blinded with suitable granular material to seal its surface. 3.6.9 Surface / Subsurface drains Surface or Subsurface drains provided to drain out seepage water from pavement courses or capillary action rise water due to high water table. Grading of materials used as per table 3.3 and 3.4 Table 3. 3. Grading Requirement for filter material for Sub surface Drain S.No. Sieve Designation Class I Per cent passing by weight Class IIClass III 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 53 mm 45 mm 26.5 mm 22.4 mm 11.2 mm 5.6 mm 2.8 mm 1.4 mm 710 micron 355 micron 180 micron 90 micron - - - - 100 92-100 83-100 59-96 35-80 14-40 3-15 0-5 - - 100 95-100 48-100 28-54 20-35 - 6-18 2-9 - 0-4 100 97-100 - 58-100 20-60 4-32 0-10 0-5 - - - 0-3 Table 3. 4.Grading Requirement for Aggregate Drains S.No. Sieve Designation 63 mm 37.5 mm 19 mm 9.5 mm 3.35 mm 600 micron 150 micron 75 micron 1. 2. 3. 4. 5. 6. 7. 8. Per cent passing by weight Type AType B -100 10085-100 -0-20 45-1000-5 25-80- 8-45- 0-10- 0-5- 3.7 3.7.1 Sub-bases and Bases (Non-Bituminous) Granular sub-base The material for granular sub- base should generally conform to the grading indicated in Tables 3.5 and 3.4 or combination thereof. Table 3. 5. Grading for coarse-graded granular sub-base materials Percent by weight passing the IS sieve IS sieve designation Grading IGrading IIGrading III 75.0 mm100–––– 53.0 mm80- 100100–– 26.5 mm55-9070-100100 9.50 mm35-6550-8065-95 4.75 mm25-5540-6550-80 RUIDP Jaipur 17 Hand Book For Road Works IS sieve designation 2.36 mm 0.425 mm 0.075 mm CBR Value (Minimum) Percent by weight passing the IS sieve Grading IGrading IIGrading III 20-4030-5040-65 10-2515-2520-35 3- 103-103-10 302520 Table 3.6. Grading for coarse-graded granular sub-base materials Percent by weight passing the IS sieve IS sieve designation Grading IGrading IIGrading III 75.0 mm100–––– 53.0 mm––100–– 26.5 mm55-7550-80100 9.50 mm–––––– 4.75 mm10-3015-3525-45 2.36 mm–––––– 0.425 mm–––––– 0.075 mm<10<10<10 CBR Value302520 (Minimum) Note: The material passing 425 micron (0.425 mm) sieve for all the three gradings when tested according to IS:2720 (Part V) shall have liquid limit plasticity index not more than 25 and 6 per cent respectively. 3.7.2 Water Bound macadam Material for water bound macadam should conform to relevant clause of Ministry’s Specification aggregate required have been summarised in Table no. 3.7, 3.8, 3.9 and 3.10. Table 3.7 Physical requirements of coarse aggregates for water bound macadam for sub base course Test 1. *Los Angeles Abrasion Value or *Aggregate Impact Value 2. Combined Flakiness and Elongation Indices (Total) *** * Test Method IS: 2386 (Part IV) IS: 2386 (Part IV) or IS: 5640** IS: 2386 (Part I) Requirement 40 per cent (Max) 30 per cent (Max) 30 per cent (Max) Aggregate may satisfy requirements of either of the two tests **Aggregates like, brick metal, kankar, laterite etc. which get softened in presence of water shall be tested for impacts value under wet condition in accordance IS:5640. *** The requirement of flakiness index and elongation index shall be enforced only in the of crushed broken stone and crushed slag. RUIDP Jaipur 18 case Hand Book For Road Works Table 3.8. Grading requirements of coarse aggregates Grading No. 1. Size Range 90 mm to 45 mm IS sieve designation 125 mm 90 mm 63 mm 45 mm 22.4 mm 90 mm 63 mm 53 mm 45 mm 22.4 mm 63 mm 53 mm 45 mm 22.4 mm 11.2 mm Percent by weight passing 100 90-100 25-60 0-15 0-5 100 90-100 25-75 0-15 0-5 100 95-100 65-90 0-10 0-5 2. 63 mm to 45 mrn 3. 53 mm to 22.4 mm Note : The compacted thickness for a layer with Grading 1 shall be 100 mm while for layer with other Grading, i.e., 2 and 3, it shall be 75 mm. Table 3.9. Grading for screenings Grading Classification 1. Size of screenings 13.2 mm IS sieve designation 13.2 mm 11.2 mm 5.6 mm 180 micron 11.2 mm 5.6 mm 180 micron Percent by weight passing the IS sieve 100 95- 100 15-35 0-10 100 90- 100 15-35 2. 11.2 mm RUIDP Jaipur 19 Hand Book For Road Works Table 3.10 Approximate quantities of coarse aggregates and screenings required for 100/ 75 mm compacted thickness of Water Bound Macadam (WBM) Sub base/ base course for 10m2 areas. Screenings Stone Screening Grading Classificati on & size 100 mm 75 mm --do-- 75 mm 1.21 to 1.43 m3 0.91 to 1.07 m3 --do-- --do-- Type A 13.2 mm Type A 13.2 mm Type B 11.2 mm --do-- For WBM sub-base/ base course (Loose Quantity) 0.27 to 0.30 m3 0.12 to 0.15 m3 0.20 to 0.22 m3 0.18 to 0.21 m3 Crushable type such as Moorum or gravel Grading classificatiLoose onqty & size Not uniform --do-- --do-- --do-- 0.30 to 0.32 m3 0.22 to 0.24 m3 --do-- --do-- Classific ation Size Range Compacted thickness Loose Qty. Grading 1 Grading 2 --do-- Grading 3 90 mm to 45 mm 63 mm to 45 mm --do-- 53 mm to 22.4 mm 3.7.2.1 General guideline and Procedure for Water Bound macadam: 1) 2) Thickness of a compacted layer should be 100 mm for 90-45 mm, size aggregates and 75 mm for 63-45 mm or 53-22.4 mm size aggregates. Screenings should generally be of the same material as coarse aggregate. However, if the use of screenings is not feasible, some other non-plastic material, such as, moorum or gravel (other than rounded river borne material) having liquid limit and plasticity index below 20 and 6 respectively may be used provided fraction passing 75 micron sieve does not exceed 10 per cent. Binding maternal need not be used if the layer is to serve as base (or is to receive black topping), or where crushable type of screenings, like, moorum is used. It is a good practice to lay a sub-base of granular/stabilised material before laying WBM. This is particularly important where the sub grade is of clayey type. Where the WBM is to be laid directly over sub grade, a 25 mm thick layer of stone screenings (Grading B) - "inverted choke" - should be spread on the prepared sub grade before the application of aggregate is taken up. In case of fine sand or silty or clayey sub grade it is advisable to lay 100 mm thick insulating layer of screening or coarse sand on the top of fine grained soil. A preferred alternative to inverted choke is the use of appropriate geosynthetics mesh. Arrangements for water, rollers in working order and templates/ other tools and equipment for checking the quality of the materials and work must be available at site before the work of laying is started. The quantities of coarse aggregates and screenings will vary, depending on the actual grading. Arrangements for lateral confinement of aggregates must be provided. This can conveniently be done by raising the shoulders in stages equal in thickness to each layer of WBM. RUIDP Jaipur 20 3) 4) 5) 6) 7) 8) Hand Book For Road Works 9) The coarse aggregate should be spread uniformly and evenly on the prepared sub- grade /sub-base by using templates placed across the road about 6 m apart. The thickness of each compacted layer should not be more than 100 mm in grading 1 and 75 mm for grading 2 and 3. Wherever possible, mechanical devices should be used to spread the aggregates uniformly so as to minimise the need for manual rectification afterwards. The spreading should be done from stockpiles or directly from vehicles. No segregation of large or fine aggregates should be allowed. The surface should be checked frequently while spreading and rolling so as to ensure the specified regularity of slopes and camber. The coarse aggregate should not normally be spread more than three days in advance of the subsequent construction operations. Three wheeled power rollers at 80 to 100 kN or tandem or vibratory rollers at 80 to 100 kN static weight should be used for rolling. Except on supper elevated portions, where the rolling should proceed from inner edge to outer edge, rolling should begin from the edge gradually progressing towards centre. Successive passes should uniformly overlap the proceeding by at least one half widths. In case screening are to be applied, rolling should be discontinued when the aggregate are partially compacted with sufficient void space to permit application of screening. During rolling slight sprinkling of water may be allowed. Complete rolling is indicated by a loose stone piece getting crushed under the roller without sinking. After the coarse aggregate has been rolled, screening to completely fill the interstices should be applied gradually over the surface. Screening should not be damp or wet at the time of application. These should not be dumped in piles but applied at a uniform rate, in three or more applications, so as ensure filling of all voids. Dry rolling should be done while the screenings are being spread so that vibrations of the roller cause screenings to settle into the voids of coarse aggregate. Dry rolling should accompanied by brooming. These operations should continue until no more screenings can be forced into the voids of coarse aggregate. Spreading, rolling and brooming of screens shall be carried out in only such lengths which are likely to be completed within one day's operation. After screenings have been applied, the surface should be copiously sprinkled with water, swept with hand brooms and rolled. This operation should be continued with additional screenings, applied as necessary, until the coarse aggregates has been thoroughly keyed, well broomed, firmly set in its full depth and a grout has been formed of screenings. The base or sub grade should not get damaged due to use of excessive quantities of water. In case lime treated soil sub-base, construction of water bound macadam should be taken up only after sub-base has picked up enough strength. Apply binding material, wherever required, in a similar fashion as screening. Continue rolling till full compaction is achieved. After the final compaction of WBM course, the pavement should be allowed to dry overnight. Next morning hungry spots should be filled with screenings or binding material, lightly sprinkled with water, if necessary and rolled. RUIDP Jaipur 21 10) 11) 12) 13) 14) 15) 16) 17) 18) 19) Hand Book For Road Works 20) No traffic should be allowed on the road until the macadam has set. The compacted WBM Course should be allowed completely dry and set before the next pavement course is laid over. WBM work should not be carried out when the atmospheric temperature is less than 00 C in the shade. Apply binding material, wherever required, in a similar fashion as screening. Continue rolling till full compaction is achieved. After the final compaction of WBM course, the pavement should be allowed to dry overnight. Next morning hungry spots should be filled with screenings or binding material, lightly sprinkled with water, if necessary and rolled. No traffic should be allowed on the road until the macadam has set. The compacted WBM Course should be allowed completely dry and set before the next pavement course is laid over. WBM work should not be carried out when the atmospheric temperature is less than 00C in the shade. After application of cut-back, the surface should be allowed to cure for at least 24 hours. Wet mix macadam: Wet mix macadam construction is an improvement over the conventional water bound macadam providing speedy and more durable construction. It differs from the water bound macadam in that graded aggregates (conforming to requirements indicated in Table 3.11) and granular materials are mixed with predetermined quantity of water in accordance with the specifications to form dense mass which is spread and wiled to approved lines, grades and cross-section to serve as pavement course(s). 21) 22) 23) 24) 25) 26) 3.7.3 Table 3.11. Physical requirements of coarse aggregates for wet mix macadam for sub- base/base courses S.No. 1. 2. 3. Test * Los Angeles Abrasion Value * Aggregate Impact Value Combined Flakiness and Elongation Indices (Total) Test Method IS:2386 (part IV) IS:2386 (part IV) or IS:5640 IS:2386 (part I) Requirements 40 per cent (Max) 30 per cent (Max) 30 per cent (Max) * Aggregate may satisfy requirements of either of the two tests The specified grading for the aggregates as per Table 3.12 and granular materials should be used for mixing. Quantity of water should not vary from OMC determined as per IS: 2720 (Pt. VIII), by more than agreed limit. Table 3.12. Grading requirements to aggregates for wet mix macadam S.No. 1. IS sieve designation 53 mm Per cent by weight passing the IS sieve 100 RUIDP Jaipur 22 Hand Book For Road Works S.No. 2. 3. 4. 5. 6. 7. 8. 9. IS sieve designation 45 mm 26.5 mm 22.4 mm 11.2 mm 4.75 mm 2.36 mm 600 micron 75 micron Per cent by weight passing the IS sieve 95 - 100 - 60 - 80 40 - 60 25 - 40 15 - 30 8 - 22 0-8 3.7.3.1 General guideline and Procedure for Wet mix macadam 1) 2) P.I. value of Materials finer than the 425 micron sieve should be less than 6. The mix should be prepared in approved mixing plant of suitable capacity having provision for controlled addition of water and forced/positive mixing arrangement, like, pug mill or pan type mixes of concrete batch/plant The mixed material should be uniformly wet and no segregation should be permitted. The mix should be spread uniformly and evenly in required quantities on the prepared sub grade/sub-base either by a ~elf-propelled paver finisher or a motor grader fitted with blades having hydraulic control suitable for initial adjustment and maintaining the same. In no case should the mix be dumped in heaps on the area. The thickness of single compacted wet mix macadam layer should not be less than 75 mm nor more than 100 mm. However, the compacted thickness of single layer of the sub-base may be increased up to 200 mm provided vibratory roller of approved type is used for compaction. The roller speed should not exceed 5 Km / hour. Rolling should continue till density achieved is at least 98 per cent maximum dry density as per IS: 2720 (Part VIII). When surface irregularity of wet mix macadam exceeds permissible tolerance or where the course is otherwise defective (like, sub grade soil getting mixed with the aggregates), the full thickness of the layer should be scarified over the affected area, reshaped with added premixed material as applicable and re-compacted. The area treated in this manner should not be less than 5 m long and 2 m wide. It is not advisable to lay the wet mix macadam during rains and the tempo of work suffers during rains. After construction of the top WMM layer will need immediate sealing with bituminous surfacing. Provision of adequate drainage for the foundation area for the construction courses assumes greater importance in this method of construction. 3) 4) 5) 6) 7) 8) 9) 10) RUIDP Jaipur 23 Hand Book For Road Works 3.8 3.8.1 Bitumen Bound Bases and Surfacing General requirement: General requirement on materials, mixing, transporting, laying, compaction, joints and construction of bituminous pavement layers are laid down in Clause 501 of his Ministry’s Specifications. 3.8.2 Prime Coat 3.8.2.1 General guideline for Prime Coat 1) Prime coat consists of application a single coat of low viscosity liquid bituminous material to a pours granular surface preparatory to the superimposition of bituminous treatment or mix. The choice of printer shall depend upon the porosity of the surface to be printed. Details are available in Clauses 501.2 of this Ministry’s Specifications. Bituminous Printer should not be applied on a wet or dusty surface. At the time of application temperature in the shade should not be less than 100C. The primer distributor should be self propelled or towed bitumen pressure sprayer capable of spaying the material uniform ally at the specified rate and temperature. Hand spraying should be resorted to only in small areas and areas inaccessible to the pressure sprayer. After application of cut back, the surface should be allowed to cure for at least 24 hours. The quantity viscosity and temperature of lying should be as specified in table 3.13 Table 3.13. Viscosity requirement and quantity of bituminous primer Type of surface Kinematic Viscosity of Primer at 600C (Centistokes) Quantity per 10sq.m (kg) 2) 3) 4) 5) Low porosity Medium porosity High porosity 30-60 70-140 250-500 6 to 9 9 to 12 12 to 15 3.8.3 Tack-Coat: 3.8.3.1 General guideline for Tack-Coat 1) The binder for tack coat should be a bituminous emulsion complying with IS: 8887 or cut-back as per IS: 217, to be used restrictively for site at sub-zero temperature or for emergency application. The quantity of binder should be as per Table 3.14. The binder should be applied uniformly with bitumen pressure sprayer capable of spraying bitumen at specified rate and temperature to provide a uniform unbroken spread of bitumen. No more than the necessary tack coat for the day's operation should be placed. The succeeding construction should be made only after curing of the tack coat RUIDP Jaipur 24 2) 3) 4) 5) Hand Book For Road Works Table 3.14. Rate of application of tack coat S.No. Type Surface Quantity of liquid bituminous material in kg per 10 sq.m. area Normal bituminous surfaces2.0 to 2.5 Dry and hungry bituminous surfaces2.5 to 3.0 Granular surfaces treated with primer2.5 to 3.0 Non bituminous surfaces a) Granular base (not primed)3.5 to 4.0 b) Cement Concrete pavement3.0 to 3.5 Note: Where the material to receive an overlay is a freshly laid bituminous layer that has not been subjected to traffic or contaminated by dust, a tack coat is not mandatory where the overlay is completed within two days. 3.8.4 Bituminous Macadam and Dense Graded Bituminous Macadam 3.8.4.1 General guideline for Bituminous macadam and dense graded bituminous Macadam 1) The work consists of construction of a single layer of compacted crushed aggregates premixed with bituminous binder. Bituminous Macadam is more open graded than the Dense Graded Bituminous Macadam. Physical requirements of aggregate for BM and Dense Graded Bituminous Macadam are given in Table 3.15. The filler shall be graded within the limit in table 3.16. For Bituminous Macadam, the bitumen content for premix should be 3 to 3.5 per cent by weight of total mix except otherwise directed. The composition of Bituminous Macadam should conform to Table 3.17. The manufacturing and rolling temperature are given in Table 3.18. For dense graded bituminous macadam aggregate gradation and requirement of mix are indicated in Table Nos. 3.19 and Marshall Properties should be according table 3.20 . The requirements for minimum per cent voids in mineral aggregate (VMA) are set out in Table 3.21. Job mix formula for Dense Graded Bituminous shall comply with Clause 507.3 of the Ministry’s Specifications and should be design in lab or other agency and should get approval from PMU before implementation. The construction operation for Dense Graded Bituminous Macadam including lying of and stress absorbing layer should be in accordance with Clause 507.4 of the Ministry's Specifications. For more detail refer Ministry’s specification clause no. 504 for Bituminous Macadam & clause no. 507 for Dense Graded Bituminous Macadam. i) ii) iii) iv) 2) 3) 4) 5) 6) 7) 8) Table3.15. Physical requirements for coarse aggregate for Bituminous Macadam and Dense graded bituminous macadam S.No. Property Test Specification RUIDP Jaipur 25 Hand Book For Road Works S.No. 1. 2. 3. Property Cleanliness (dust) Particle shape Test Grain size analysis1 Flakiness and Elongation Index (Combined)2 Los Angeles Abrasion Value) Aggregate Impact Value4 Soundness:5 n Soundness:5 Sodium Sulphate Magnesium Sulphate Water absorption6 Coating and Stripping of Bitumen Aggregate Mixtures7 Retained Tensile Strength8 Specification Max 5% passing 0.075mm sieve Max 30% Max 35% Max 27% Strength* 4. Durability 5. 6. Stripping 7. Water Sensitivity** Max 12% Max 18% Max 2% Minimum retained coating 95% Min 80% Water Absorption Notes: 1. IS:2386 Part I5. IS:2386 Part 5 2. IS:2386 Part I6. IS:2386 Part 3 (the elongation test to be done only on non-flaky aggregates in the sample) 3. IS:2386 Part 4*7. IS:6241 4. IS:2386 Part 4*8. AASHTO T283** * Aggregate may satisfy requirements of either of these two tests. ** The water sensitivity test is only required if the minimum retained coating in the stripping test is less than 95%. Table 3.16. Grading requirements for mineral filler S.No. IS Sieve (mm) Cumulative per cent passing by weight of total aggregate 1. 2. 3. 0.6 0.3 0.075 100 95 - 100 85 - 100 RUIDP Jaipur 26 Hand Book For Road Works Table 3.17. Composition of bituminous macadam Mix designation Nominal aggregate size Layer thickness IS Sieve
 

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