08 ok CW2C DRAINAGE AND OTHER WORK ITEMS

MATERIAL REQUIREMENTS MATERIALS The Contractor shall submit to the Engineer for his approval details and samples of materials he intends to use for the construction of ditches included i

DRAINAGE AND OTHER WORK ITEMS

TABLE OF CONTENTS

I BOX CULVERTS

II DITCHES

III CATCH BASINS, MANHOLES, INLETS, AND OUTLET

IV MORTARED STONEWORK

V PAVEMENT MARKINGS

All materials must be in conformity with the Specifications

I BOX CULVERTS

1 MATERIAL REQUIREMENTS

Box culverts shall be cast in situ and in accordance with details as shown in the Drawings The Contractor shall submit, for the Engineer’s approval, arrangement for the construction of Reinforced Concrete Box Culverts Unless otherwise directed by the Engineer, applicable provisions of Division 7 - Structural Works shall be read into and become part of this Clause

Waterstops shall be heat-weldable ribbed PVC with centerbulb Unless otherwise shown on the Drawings, waterstops shall have minimum weight 1.0 kg / meter, elongation at break at least 250%, and tensile strength at least 12 MPa

2 EXCAVATION

Prior to starting excavation the Contractor shall take all necessary measures to keep the excavation free from free-surface water or surface water from pre-loading and soft soil treatment

Except as otherwise instructed by the Engineer, in areas of fill, filling, pre-loading and soft soil treatment shall be completed and the surcharge embankment reach a stable condition, before excavation begins, subject to the approval of the Engineer All excavation shall

be carried out so as to minimize damage to existing surfaces

Soft spots in the bottom of box culvert excavation shall be removed and the resulting void immediately backfilled with Granular Backfill When the Engineer instructs this additional treatment it will be paid for under the relevant clauses of these Specifications

Where the Engineer considers that soft spots are due to the Contractor’s failure to fulfil his obligations under any clause of these Specifications then the Contractor shall, at his own expense, undertake the additional excavation and replacement with Granular Backfill to the satisfaction of the Engineer

Any suitable material below the level of the box culvert bed which is removed unnecessarily shall be replaced at the Contractor’s expense with Granular Backfill

3 BEDDING FINISHING

Excavation shall be executed to the true line and level directed by the Engineer Where indicatd on the Drawings bedding shall be installed or foundation treatment carried out

4 BACKFILLING AND REINSTATEMENT

Backfilling shall not commence until in the opinion of the Engineer, the concrete has achieved sufficient strength Backfilling shall be carried out in accordance with the requirements of Section 03200, except that the material used for backfill around and above the box culvert for a minimum distance of 50 cm shall be sand in place of excavated material Where insufficient suitable material is available, surplus material from any other excavation shall be used On completion of backfilling, the area excavated shall be reinstated to its

original condition but the Engineer may waive or modify this requirement if the area is to be overlaid or reconstructed under other clauses of this Contract

II DITCHES

1 MATERIAL REQUIREMENTS

MATERIALS

The Contractor shall submit to the Engineer for his approval details and samples of materials he intends to use for the construction of ditches included in this specification section

BEDDING

Granular material for bedding shall be in accordance with clause 4.2, table 4 of TCVN 7570

– 2006 subject to the approval of the Engineer

Lean concrete for bedding shall be class C10 bedding or blinding concrete in accordance with the requirements of Specification Section

07100 “Concrete and Concrete Structures”

MORTARED STONE

Mortared stone lining shall conform to the requirements specified in Specification Section 04400 “Mortared Stonework”

CONCRETE

Pre-cast and cast in situ concrete used for all structural work described in this Specification Section shall be of the classes indicated on the drawings and shall conform to the requirements specified in Specification Section 07100 “Concrete and Concrete Structures”

REINFORCING STEEL FOR CONCRETE

All reinforcing steel used in the works shall conform to the requirements specified in Specification Section 07500 “Reinforcing Steel”

2 ROADSIDE DITCHES CONSTRUCTION

The Contractor shall excavate, fill, and shape the ditches to the grades shown on the construction drawings and to the profiles shown on the typical drawings of ditches or as otherwise directed by the Engineer

For open ditches lined with mortared stone the Contractor shall remove and dispose of all excavation material For cast in-situ concrete ditches excavation shall be in accordance with the provisions

of Specification Section 03200 “Structural Excavation” No material shall be left on site such that it may be washed or otherwise deposited back into the excavation or the completed ditches

Construction of the cast in-situ concrete or the stone lining for ditches as specified in this Specification Section shall not begin until after the Engineer approves the excavated formations for the ditches

The finish to all ditches shall be sufficiently smooth and uniform to ensure the free flow of water without ponding during periods of low flow

3 TOLERANCES, RECTIFYING AND MAINTENANCE

DIMENSIONAL TOLERANCES

Grades of ditch inverts against those specified or approved:

±5 mm at any point Ditches alignments and the shape of cross sections as specified in the Drawings: ±2 cm at any point

RECTIFYING UNSATISFACTORY WORK

All materials and workmanship used in the construction of culverts shall be subject to the inspection and approval of the Engineer Where appropriate the Engineer will issue instructions for any remedial work found necessary as a result of unsatisfactory work by the Contractor The Works will not be approved until such time as they have been completed to the satisfaction of the Engineer

Remedial work may include but not

be limited to:

surface profiles as often as necessary to obtain an accurate record of the physical conditions;

 Additional excavation or fill, which could include backfilling new work and re-excavating it to the specified dimensions, lines, and grades, and

work

No additional payment shall be made for the extra work or quantities used for the rectification

III CATCH BASINS, MANHOLES, INLETS, AND OUTLETS

1 MATERIAL REQUIREMENTS

MATERIALS

The Contractor shall submit to the Engineer for his approval details and samples of materials he intends to use for the construction of Catch Basins, Manholes, Inlets and Outlets to culverts and ditches included in this specification section

BEDDING

Fine sand fill/bedding shall be black sand (river sand) The sand shall be a fine sand complying with the requirements of Table 1 of TCVN 7570-06 with a fineness modulus of 0.7 to 2.0 Organic and other impurities shall be in accordance with table 2 of TCVN

7570-06 as follows:

It will not be necessary to determine the alkali reactivity or the chloride content of the sand for this use

Sand shall be sampled and tested in accordance with TCVN 7572:2006 (Aggregates for concrete and mortar – Test methods) Granular material for bedding shall be in accordance with clause 4.2, table 4 of TCVN 7570

– 2006 subject to the approval of

the Engineer

Lean concrete for bedding shall be class C10 bedding or blinding concrete in accordance with the requirements of Specification Section

07100 “Concrete and Concrete Structures”

CONCRETE

Pre-cast and cast in situ concrete used for all structural work described in this Specification Section shall be of the classes indicated on the drawings and shall conform to the requirements specified in Specification Section 07100 “Concrete and Concrete Structures”

REINFORCING STEEL FOR CONCRETE

All reinforcing steel used in the works shall conform to the requirements specified in Specification Section 07500 “Reinforcing Steel”

MORTARED STONE

Mortared stonework shall conform to the requirements specified in Specification Section 04400 “Mortared Stonework”

STEELWORK

22TCN288:2002 and shall be galvanised in accordance with AASHTO M232

MORTAR

Mortar for joints or other works shall only be used if required by the Engineer, or so indicated on the Drawings If or when required mortar shall comply with specification section 08100 “Cement Mortar”

2 SITE PREPARATION

The Contractor shall carry out any excavation that may be required for Catch Basins, Manholes, Inlets and Outlets in accordance with the provisions of Specification Section 03200 “Structural Excavation” The Contractor shall be responsible for all dewatering and temporary support works for the excavations and all other necessary temporary works that may be required during construction

3 DELIVERY, STORAGE AND HANDLING

Materials delivered to site shall be inspected for damage, unloaded, and stored with minimum handling Any damaged materials shall be rejected and replaced at the Contractor’s expense

4 CONNECTIONS

Culvert pipes or ditch sections shall be placed or cast and properly bedded before being cast into or built into catch basins, manholes or inlet and outlet structures

5 MANHOLE COVERS, CATCH BASINS AND FRAMES

Covers to manholes and catch basins shall be fabricated, supplied and installed complete with steel frames and lifting points as indicated on the drawings

IV MORTARED STONEWORK

1 REFERENCE STANDARDS

Mortared stonework shall comply with the requirements of standard TCVN 4085:2011 Structure of stone brick – Regulations on Construction and Acceptance

2 STONE

Stones shall consist of field stone or quarry stone They shall be sound, tough, durable, dense, resistant to the action of air and water, and suitable in all respects for the purpose intended

Mortared Stonework: Unless otherwise indicated on the Drawings

or directed by the Engineer, the stone shall meet the gradation requirements shown in Table 1

The Quality and dimensions of the stones shall be approved by the Engineer prior to their use Stones shall be as nearly rectangular in shape as practicable

Approximate Given Size Equivalent Cubic

Dimension (mm)

Total Size Smaller than Given Size (%)

Weight (kg) Volume(cu.m.)

* Material shall consist of spills and rock fragments graded to provide a stable compact mass

3 CEMENT MORTAR

Cement Mortar shall be in accordance with the provisions of Specification Section 08100 “Cement Mortar” or as directed by the Engineer

4 WORK PREPARATION

PREPARING FORMATIONS OR FOUNDATIONS

The Contractor shall prepare formations for mortared stonework to the lining of open ditches in accordance with the provisions of Specification Section 04200 “Ditches”

The Contractor shall prepare foundations and trenches for cut-off walls or other structures made of mortared stonework in accordance with the provisions of Specification Section 03200 “Structure Excavation”

PREPARING STONE

The Contractor shall clean the stones of all defects that may impair the bond with the mortar The Contractor shall thoroughly wet the stones long enough for the stones to absorb water to

near saturation prior

to laying

PLACING STONE LINING

Surfaces to receive mortar shall be cleaned of oil or clay or other contaminants and thoroughly saturated before the mortar is applied Free surface water shall be removed before application of the mortar

The Contractor shall place a bedding of fresh mortar at least 3 cm thick on the prepared formation The Contractor shall construct this mortar bedding progressively by laying the surface stones in such a manner that the stones are always securely bedded in the mortar before it hardens

The Contractor shall place the stones firmly against each other to provide the required paving thickness measured perpendicular to the slope The Contractor shall then place additional mortar to completely fill all spaces between the stones The finished surface of the mortar shall be almost flush with the surface of the lining but the mortar shall not cover the stones

The work shall progress from the bottom of the slopes towards the top The Contractor shall finish the surface immediately following the initial set of the mortar by sweeping the surface with a stiff broom The Contractor shall cure the finished surfaces as specified for concrete work in Specification Section 07100 “Concrete and Concrete Structures”

The Contractor shall trim and finish adjacent slopes and shoulders to ensure a tight and smooth interface with the mortared stonework The interfaces shall allow unobstructed drainage and prevent scour

at the edges of the work

5 CONSTRUCTING MORTARED STONEWORK STRUCTURES

The Contractor shall construct mortared stonework structures by covering the base of the foundation with mortar to a depth of 60% of the maximum dimension of the stones The Contractor shall then immediately place the stones in the unset mortar The Contractor shall add additional mortar and repeat the process until the structure is complete The Contractor shall then add mortar to the top of the cut-off until he obtains a screened level top surface

The Contractor may construct mortared stonework without forms if the stone can interlock sufficiently and if he uses stiff mortar

The Contractor shall finish and cure exposed surfaces of mortared stonework structures as specified in Specification Section 07100

“Concrete and Concrete Structures”

The Contractor shall backfill around the finished and cured mortared stonework in accordance with the provisions of Specification Section

03200 “Structure Excavation”

V PAVEMENT MARKINGS

1 REFERENCE STANDARDS

The following Standards in their latest edition shall be particularly applied to the works covered by this Specification

Signs and Signals

based paints Specification and Test Method

Solvent based

paints Specification and Test Method

Technical

requirements and test methods

markings - Road markings, construction and acceptance

Paints

Thermoplastic Stripping Material (Solid Form)

2 PREPARATION OF ROAD SURFACE

The work of road marking shall include the following:

a) Cleaning of the pavement surfaces to remove all dust, dirt, grease, oil and other foreign matter

b) Application, protection and drying of paint coatings

c) Protection of pedestrians, vehicular or other traffic

d) Protection of all parts of the road structure and its appurtenances against disfigurement by spatters splashes or smirches of marking material

e) Supply of all tools, labour and marking materials necessary for the entire work Thermoplastic shall not be applied during rain or wet weather or when air is misty, or when