06 7 ok CW2C BASE

CMDRCP / CW2C PACKAGE CW2C KM 18+200 – KM 23+450 BASE COURSES 1/ 13 PHUONG THANH - QUYET TIEN - ANH GIANG – THANG LOI JOINT VENTURE CMDRCP / CW2C PACKAGE CW2C KM 18+200 – KM 23+450 TABLE OF CONTENTS I MATERIAL REQUIREMENTS II EQUIPMENT AND CHECKING III CONSTRUCTION OF AGGREGATE BASE AND LEVELLING LAYERS IV EXECUTION OF BASE COURSES V INSPECTION AND ACCEPTANCE 2/ 13 PHUONG THANH - QUYET TIEN - ANH GIANG – THANG LOI JOINT VENTURE CMDRCP / CW2C PACKAGE CW2C KM 18+200 – KM 23+450 CONSTRUCTION OF THE BASE AND BASE COURSES I Material requirements All the material was tested and approved by Engineer before using The Contractor shall submit to the Engineer to know about the source of material and the Engineer will approve these sources before the material is delivery to site Where the material does not meet the requirements of Technical Standards, the Contractor shall provide materials from other sources The transportation of materials from the processing stage will be accompanied by the manufacturer's certificate and report of testing to indicate that material in accordance with the requirements of the specification Reference to the macadam material: The most recent printing of the following Vietnamese or AASHTO tests shall apply to the materials covered in this Section: The most recent editions of the following standards shall apply to the materials covered in this Section:   TCVN8859:11 Construction and approval methods on grade aggregate foundation in highway pavement 22TCN346-06 Testing procedure on definition of compaction of road foundation and embankment by sand cone method  22TCN333-06 in laboratory Procedures of soil and macadam compaction  22TCN332-06 for soil and Testing procedures on definition of CBR value macadam in aboratory  AASHTO T89 Determining the Liquid Limit of Soils  AASHTO T90 Determining the Plastic Limit of Soils  AASHTO T96 Degradation of Standard Method of Test for Resistance to Small-Size Coarse Aggregate by Abrasion and Impact in the Los Angeles Machine  AASHTO T104 Magnesium Soundness of Aggregate by use of Sodium or Sulphate  3/ 13 AASHTO T180 Relations of Standard Method of Test for Moisture-Density PHUONG THANH - QUYET TIEN - ANH GIANG – THANG LOI JOINT VENTURE CMDRCP / CW2C PACKAGE CW2C KM 18+200 – KM 23+450 Soils Using a 4.54-kg (10-lb) Rammer and a 457-mm (18-in.) drop  AASHTO T193 Bearing Ratio  ASTM D4791 Standard Test Method for Flat Particles, Elongated Particles, Standard Method of Test for The California or Flat and Elongated Particles in Coarse Aggregate Materials of construction must, before putting in the work, be tested to check the grain composition analysis, the best moisture if meet the technical standards and regulations approved by the Engineer will be allowed to spread In addition, all construction materials of macadam aggregate foundation must meet the technical requirements specified in the Regulations and Specification Materials shall be so stored and handled as to assure the preservation of their quality and fitness for construction Materials, even though approved before storage or handling, may again be inspected and tested prior to use Stored material shall be located to facilitate prompt inspection Handling and stockpiling of aggregates shall be to the approval of the Engineer and at all times be such as to eliminate segregation of the various sizes and contamination Aggregate stockpiles for base course and base shall be protected from rain to prevent saturation of the aggregates which would result in a reduction in the quality of the placed material or adversely affect the placement of the material Where separate size materials are to be blended to meet the gradation, such blending shall be as directed by the Engineer and shall be accomplished prior to delivery to the roadway MATERIAL REQUIREMENTS The aggregate for base course and aggregate levelling course shall consist of hard, durable particles and shall be crushed stone, crushed slag, or crushed or suitable natural material and filler of natural or crushed sand or other finely divided mineral matter The aggregate shall be free from vegetable matter and lumps or balls of clay, and shall be of such nature that it can be readily compacted to form a firm and stable base The materials shall comply with the requirements given in tables and below Table Grading Requirement for Aggregate Standard (mm) 50 4/ 13 Mass Percent Passing Dmax = 37.5mm Dmax = 25mm Dmax = 19mm 100 - - PHUONG THANH - QUYET TIEN - ANH GIANG – THANG LOI JOINT VENTURE CMDRCP / CW2C PACKAGE CW2C KM 18+200 – KM 23+450 37,5 5/ 13 95 - 100 100 - 25 - 79 - 90 100 19 58 - 78 67 - 83 90 - 100 9,5 39 - 59 49 - 64 58 - 73 4,75 24 - 39 34 - 54 39 - 59 2,36 15 - 30 25 - 40 30 - 45 0,425 - 19 12 - 24 13 - 27 0,075 - 12 - 12 – 12 PHUONG THANH - QUYET TIEN - ANH GIANG – THANG LOI JOINT VENTURE CMDRCP / CW2C PACKAGE CW2C KM 18+200 – KM 23+450 No Properties Aggregate Test Method Base Base Los-Angeles wear of aggregate (LA), % ≤ 35 ≤ 40 AASHTO T96 Soaked CBR at maximum dry density ≥ 100 - AASHTO T193 Liquid Limit (WL), % ≤ 25 ≤ 35 AASHTO T89(*) Plasticity Index (Ip), % ≤6 ≤6 AASHTO T90 (*) PP Index = Plasticity Index Ip x % material ≤ 45 ≤ 60 ≤ 18 ≤ 20 passing portion 0.075mm Percent by weight of aggregate with diamond or flattened shapes, % Compacted Density (Kyc), % AASHTO D4791 (**) ≥ 98 ≥ 98 AASHTO T180 Note: (*) Liquid Limit, Plasticity Index are specified by test with material passing sieve 0.425 mm (**) Aggregate with diamond or flattened shapes has thickness or width less than 1/3 length or equivalent; Test is conducted with various sieves of diameter of more than 4.75mm and accounting for more than 5% of sample quantity Aggregate with diamond or flattened shapes content of taken sample is average results certified for each sieve Aggregate with a Dmax = 25mm is appropriate Base Course Aggregate with Dmax = 19mm (Aggregate Levelling Course) shall be used for levelling and strengthening existing pavement structure in the rehabilitation of roadway sections 6/ 13 PHUONG THANH - QUYET TIEN - ANH GIANG – THANG LOI JOINT VENTURE CMDRCP / CW2C PACKAGE CW2C KM 18+200 – KM 23+450 II Equipment and checking All kinds of construction equipment have been tested and registered for its activities And they are mobilized for the project was approved by the Engineer Use of equipment with the best performance, ensure high productivity, good quality, low cost, and reducing of the hard work for employees Constructional flow line must focus on synchronous and the balance between plant productivity and manual labor It must be based on characteristics of the Works and construction technology, Schedule, scope of work and other requirement in the Projects Regular and timely improvement of construction equipment and manual labor in order to ensure consistency, balance and facilitate the application of advanced construction technology Constantly improve the management level, technical level and take the repair construction equipment, well observed periodic maintenance and repair for equipments Equipping with proper facilities for the technical maintenance and repair of construction equipment, corresponding to equipped capacity Construction equipment and material shall be managed and organized and stable in the construction group as well as highly specialized The management and use of materials, equipment (including use, maintenance and moving) must comply with the specification of manufacture and competent authorities for the driver, operator …Assign the driver, driver and operator to match with trained professionals and workers of skills The vehicles, construction machines were put into operation, ensuring the technical reliability and safeness For these vehicles, construction machines must be registered for safety, before being put into execution, must fulfill the registration test under the provisions of the competent authorities of the State of Vietnam The technical maintenance must be done by the competent group To organize a team of professional maintenance and repair techniques for each type of construction equipment and machines 7/ 13 PHUONG THANH - QUYET TIEN - ANH GIANG – THANG LOI JOINT VENTURE CMDRCP / CW2C PACKAGE CW2C KM 18+200 – KM 23+450 Construction Equipments as follows: - - Equipment Unit Quantity Bulldozer ≥140 CV each Front Loader ≥2,4m3 each Excavator 1.6 m3 each Aggregate paver 60m3/h each Roller 25ton each Steel roller – 12ton each Tired roller each Dump truck ≥10m3 each Motor grader each Water spraying truck each Equipment for surveying work + Total station + Surveyor's level : 02 each + Ruler, mirror, rod : 04 each + Steel Meter for accuracy 0,1 mm : 01 each : 02 each Equipment at site: + Full set of test devices III Construction of Aggregate Base and Levelling layers Preparation of road bed After the completion of subgrade, the preparation the road bed in according to the specification, including repair of defects on the top of subgrade K98, in the detail as follows: - Repair the all defects on the road, to clean the surface, to wet the surface Setting up the road bed before commencement of work The contractor will carry out the repair the road bed to ensure its accuracy, sufficiently dimension in shape To construct the fish bone ditch both sides of road with distance of 10 - 15m, to set up 01 water drainage trench Equipment and Manpower The Contractor spread the macadam aggregate by the Aggregate paver (Aggregate Base) in combine with the motor grader (Aggregate Base) 8/ 13 PHUONG THANH - QUYET TIEN - ANH GIANG – THANG LOI JOINT VENTURE CMDRCP / CW2C PACKAGE CW2C KM 18+200 – KM 23+450 Spread layer is allowed a maximum of 18cm (after compacting), Aggregate paver has the vibration bar to ensure the density ≥ 90% immediately after spreading The test equipment in the construction process: - Dice control the thickness and cross fall or camber The standard sieve and balance for analysis of grain The Sand Equivalent Test Set (to check for dirt) Equipment determine the moisture content of aggregate base and base Fully equipped the devices for testing of macadam aggregate in lab and site of Contractor Sand Cone Test Set to check the density Other construction equipment beside of the spreader: - Dump truck Water spray equipment in all phases of construction: tank truck, water pump with tap, water sprayer with portable showers watering by hand The compaction equipment: + Steel roller - 8T + Vibration roller 12-35 T + Steel roller 10 - 12t IV Execution of base courses Construction of Base - The thickness of the aggregate base is 50cm, so it is divided into three layers for the construction To facilitate the construction as well as the movement for the construction vehicles the construction will executed alternatively 1/2 the width of the Road Base is spread by paver machine 1.1 Trial Sections Before either base construction is started, the Contractor shall spread and compact trial sections as directed by the Engineer The purpose of the trial section is to check the suitability of the materials and the efficiency of the equipment and construction method which is proposed to be used by the Contractor Therefore, the Contractor must use the same materials, equipment and procedures that he proposes to use for the main work One trial section of a lane’s width by 150 meters in length shall be made for every type of material and/or construction equipment/procedure proposed for use Equipment for the work must be mobilized to site and setting up the construction site before commencement of work The construction equipment includes of dump truck, water spraying equipment including tank truck, pump with hose, hand watering sprayer, spread machine, the compaction means including steel rollers 8-10 T, Bomag Roller, SAKAI Roller 12 - 35T and steel rollers 10-12 T Determining the spreading coefficient: The spreading coefficient K is determined by formula γCmax K K sp 9/ 13 = PHUONG THANH - QUYET TIEN - ANH GIANG – THANG LOI JOINT VENTURE CMDRCP / CW2C PACKAGE CW2C KM 18+200 – KM 23+450 γCtn In which : + γCmax The maximum dry density of macadam aggregate according to standard result of testing density + K: is defined density equal to or greater than 0.98 + γCTN: dry density of macadam aggregate has not been compacted (according to experience Ksp = 1.28 ÷ 1.38) Construction of macadam aggregate includes of the following steps: Material preparation: Aggregate be watered at the stocking yards for ensuring that the humidity is greater than the optimum moisture content from -3% ÷ 2% Transportation of Aggregate Grading and spreading of Aggregate Rolling and compacting to specified density Maintenance of Aggregate The sequence of construction as follows: Piling of the piles, stretching wire to the level so that the macadam after spreading and compacting Macadam aggregate after exploiting in the quarries will gathered at the storage area (to check the character of macadam aggregate at the storage area and approved by Engineer in writing) Using the front loader to load to the dump truck then transported to the site (macadam aggregate must be met the needed moisture to prevent the segregation in the transportation Spreading width is calculated wider than the requires 20 cm to roll so that the outer edge also achieve the specified density The moisture of material is always best If it is not met the requirement, taking the adjustment by drying If the material is too dry, spray with water by shower to avoid the drifting of the small particles The Contractor shall adjust moisture in yards for materials to ensure uniformity In the construction process to regularly monitor surface elevation of macadam aggregate, the compensation or removing to the uneven areas shall be taken by worker, to ensure the macadam aggregate surface is always been flat, creating a compacting homogeneous mass, creating horizontal slope as designed In case occurrence of segregation, ripples or improper during the spreading it must be taken the repair of it There is a compensation after compacting, then the lower surface must be plough with depth of 5cm before compensation of material The compacting is done immediately after spraying with the sequence: preliminary rolling, densely rolling and completion rolling.This process is done when the material approaches the density requirements Density of material is certified by the methods of sand cone under the presence of the Engineer Rolling sequence: Rolling by Preliminary rollers 8-10T with 3-4 times / points with V = 1.5 -: - 2km / h Use vibration roller 25T pass 12 -18 times / points with V = 2.5 -: - km /h Rolling for completion by steel roller 10-12t, with 3-4 times / points with V = km / h Number of times be determined be needed rolling through the test results to achieve density requirements 10/ 13 PHUONG THANH - QUYET TIEN - ANH GIANG – THANG LOI JOINT VENTURE CMDRCP / CW2C PACKAGE CW2C KM 18+200 – KM 23+450 - It must be wet with water during the process to compensate for evaporation of water during construction and keep the surface moisture during compacting Density requirements: K ≥ 98% of the entire layer, in the process, it is regularly checked density by sand cone method The purpose of trial compaction for the determination of compaction coefficient and rolling passes on a point, then giving the proposal from the construction requirements in accordance with the process and technological lines the stages: prepare spread, compaction, quality control materials after shipment, check the availability of vehicle quality, motorcycles, to assign the proper manpower to each working assembly After determining the coefficient of compaction, rolling passes and approved by the Employer and Engineer, will spread on a large scale 1.2 Spreading on a large scale Setting up a working group for execution of foundation to undertake the work The construction on a large scale is done as above tested section Spreading of materials: + Base is carried out by Contractor into layers with calculated thickness (before rolling), so as to achieve the designed thickness + The material is sprayed with a width greater than design 20 cm 40cm each side of spread line to ensure compaction + Compensation and rolling, retain the moisture Setting up the rolling line after testing rolling Use a light roller (8-10T) to preliminary compacting base, then use steel rollers and vibrating rollers to achieve density requirements Rolling passes is based the actual results of after trial compaction to achieve the necessary density and optimal rolling It must be taken the remedy immediately or compensate material to the uneven points or ripples during the spraying if there is any segregation or has not yet reached a density requirements, material of entire such place must be replaced on new macadam aggregate, no mixing or compensation in place Check regularly to monitor the spread materials Compacting right along the edges and gradually goes to the center vertically At the location that the roller is able to access, the worker shall use the plate vibrator to compact to the required density On the sections with cross fall, compacting gradually from the low edge to higher edge Compacting shall be continued until no wheel rolling tracks on the surface layer, material meet the density and stability Process rolling is conducted as follows: + Preliminary rolling :Stability rolling the aggregate by roller 8−10t + Compacting rolling : Vibration roller 25t + Completion rolling :Steel roller 10−12 t Checking the density by sand cone method The macadam aggregate after being completed must be met the requirement of shape, level, density, flat and approved by Engineer and Employer Curing of the macadam aggregate layer - No transportation vehicles are allowed moving on the surface of the base layer before spraying of the bitumen and kept regularly to water on its surface to ensure the moisture, the moisture watering just 11/ 13 PHUONG THANH - QUYET TIEN - ANH GIANG – THANG LOI JOINT VENTURE CMDRCP / CW2C PACKAGE CW2C KM 18+200 – KM 23+450 - V stopped days before spraying of the bitumen on the surface of base After construction is completed, base layer has been compacted and layer is regularly watered on the surface by a watering tank truck with shower, minimize movement on this surface The curing of base layer is done continuously during the construction process, only being stopped if execution the upper layer or the surface of the base layer is spraying bitument (depending on the weather conditions and must be stopped few days before spraying of bitumen) Inspection and Acceptance - - - - - - - - 12/ 13 Check quality of macadam aggregate before during construction The Contractor will draw the chart of quality control materials during construction process to monitor all of the materials being used on site The scope of the tests will be approved by Engineer, but at least ensure the following requirements: The supporting test data required for initial source approval of the material shall include all the tests specified in this Section on at least three representative samples from the proposed material source, selected to represent the range of material quality likely to be obtained from the source Where observed changes in the material or in its source or in its method of production occur the material shall be resubmitted for source approval All holes in the finished work made by density testing or otherwise during testing shall be backfilled by the Contractor without delay Holes shall be filled with the specified material and compacted to the density and surface tolerance requirements of this Specification Section During construction routine material quality control testing shall be carried out to monitor the material being brought on site The extent of the testing shall be subject to the approval of the Engineer, but shall be at least as detailed below For every 3000 cubic meters  plasticity index tests  particle grading tests  maximum dry density determination  CBR Test The density and moisture content of the compacted material shall be routinely determined using –AASHTO T180 The test shall be made to the full depth of the layer at locations as directed by the Engineer, but not more than 200 m apart For the acceptance of aggregate delivered to the site for construction: samples shall be taken from material at the site and tests shall be conducted for every 1000 cubic meters from each material supply source or when material quality is extraordinary Material shall meet all physical properties specified in Tables Nos 1&2 and compacting test conducted inside the Laboratory Moisture, aggregate material separation (visual observation and checking sieve particle) Test on moisture and sieve particles shall be conducted for every 200 m3 aggregate or every shift; Compacted density: tests shall be conducted on every finished aggregate layer by sand cone according to AASHTO T180 or equivalent process as required by the Engineer At the final stage of compacted density, test for checking compacted density shall be frequently performed and taking as basis for completion of compact works, test for compactness shall be conducted for every 800m2 at each random position; PHUONG THANH - QUYET TIEN - ANH GIANG – THANG LOI JOINT VENTURE CMDRCP / CW2C PACKAGE CW2C KM 18+200 – KM 23+450 - - Flatness and geometric factors shall be checked according to the requirements specified in Table No.3 These testing data will be basis for acceptance of works FOR FINAL CHECKING AND ACCEPTING OF CONSTRUCTION WORKS Density: tests shall be conducted for every 7000 m2 at two random positions (in case using grader, test will be performed at random positions); For geometric factors checks shall be made on 20% of completed works in accordance with the requirements of Table No.3 TOLERANCES FOR ACCEPTANCE The allowable tolerances for Aggregate Base after compaction are as shown in Table The surface of all aggregate base and levelling layers shall be free of irregularities which can hold moisture and the camber of all such surfaces shall comply with that shown on the Drawings When testing the regularity of aggregate base and levelling course surfaces to be treated with bituminous surfacing, all loose material shall be removed by hard brooming Tolerances for Aggregate Base Items checking Layer Thickness Permitted Variation from Drawings Base Base + 10 mm + mm Checking frequency Measurement of cross-section shall be conducted for Surface Level -10 mm -5 mm every 40-50 m for straight section Width on Top -50mm Cross Fall or Camber + 0.5% + 0.3% Surface Irregularity by 3-m ≤ 10 mm ≤ mm straight edge 13/ 13 -50mm and 20 – 25 m for horizontal or vertical cures One position for every 100m PHUONG THANH - QUYET TIEN - ANH GIANG – THANG LOI JOINT VENTURE ... Vibration roller 12-35 T + Steel roller 10 - 12t IV Execution of base courses Construction of Base - The thickness of the aggregate base is 50cm, so it is divided into three layers for the construction... THANG LOI JOINT VENTURE CMDRCP / CW2C PACKAGE CW2C KM 18+200 – KM 23+450 CONSTRUCTION OF THE BASE AND BASE COURSES I Material requirements All the material was tested and approved by Engineer before... to eliminate segregation of the various sizes and contamination Aggregate stockpiles for base course and base shall be protected from rain to prevent saturation of the aggregates which would result