GENERAL SPECIFICATIONS

1. MATERIALS

Materials to be used for the work shall meet the requirement specified in the standard specifications (Blue Book) issued by Department of Public Works and Highways, the Republic of the Philippines.

1.1 Water

The contractor shall make his own arrangements for the provision of all water necessary for concrete, mortar or any other purpose on works, at his own expense. Only clean water free from all deleterious matter shall be used for mixing mortar or concrete. The details shall be referred to item 311, Part E of volume II, Blue Book.

1.2 Cement

Unless otherwise specified “Cement” shall mean ordinary Portland cement, and the details shall be referred to item 700, Part I of volume II, Blue Book.

The cement shall be stored in such manner that can prevent their deterioration or the intrusion of foreign matter and immediately upon arrival on the site of the work, in substantial waterproof bodegas, with floor raised from the ground sufficiently high to be free from dampness.

1.3 Aggregates

Concrete aggregate shall conform to the requirement of item 311, Part E of volume II, Blue book. Samples of the fine and course aggregates to be used shall be submitted for testing before the actual concreting operations are to begin. It shall be the responsibility of the contractor to designate the source of aggregates and submit them for testing. No concrete work shall commence unless an evidence of approved aggregates is confirmed by the consultant.

The maximum size of the aggregate shall be not larger than 1/5 of the narrowest dimension between sides of forms of the number for which the concrete is to be used nor larger than ¾ of the minimum clear spacing between individual reinforcing bar or bundles of bars.

Aggregate shall be stored in such a manner as to avoid the inclusion of foreign matter.

1.4 Concrete Masonry Blocks

Concrete masonry blocks shall conform to the requirements of item 704, Part I of volume II, Block Book. Dimensions and tolerances shall be specified on the drawings.

Concrete blocks shall be sound and free of cracks or other defects that would interfere with the proper placing of the block or impair the strength and performance of the construction. Blocks that are intended to serve as a base for plaster or stucco walls shall have sufficiently rough surface to afford good bond. Where the blocks are to be used in exposed wall construction, the face or faces that are to be exposed shall be free from chips, cracks or other imperfections.

1.5 Timber

Lumber of the different species herein specified for the various parts of the structure shall be all seasoned sawn straight, sun-dried or kiln-dried and free from defects and other imperfections impairing its strength, durability, and appearance.

Unless otherwise specified on the plans, the lumber species shall be used as specified in item 1003.3.2.2, part C of volume III, Blue book. Rough lumber for framing and siding boards shall be air dried or sun-dried such that its moisture content shall not exceed 22 percent. Dressed lumber for exterior and interior finishing, for doors and windows, millworks, cabinet work and floor boards shall be kiln-dried and shall not have a moisture content of 14 percent at the time of installation of structure.

Plywood shall conform to the requirement of the Philippine Trade Standard 631-02. Thickness of a single layer laminate shall not be lees than 2mm. The laminate shall be superimposed in layers with grains crossing at right angle in successive layers to produce stiffness. The laminate and face veneers shall be bonded with water resistant resin glue, hot pressed and pressure treated. Ordinary tanguile or red lauan plywood with good quality face veneers, 6mm thick shall be used for double walling and ceiling not exposed to moisture; waterproof or marine plywood shall be used for ceiling exposed to moisture such as a toilets and eaves, and ceiling to be finished with acrytex.

1.6 Reinforcing Steel

The reinforcing steel shall meet the requirements of item 710, part I of volume II, Blue Book. Provided the minimum dimensions, cross sectional area and tensile properties shall meet the physical requirement for the size and grade of steel specified.

All reinforcing bars requiring bending shall be cold- bent to the shapes shown on the drawings. Bars shall be bent around a circular pin having the

appropriate diameters in relation to the diameter of the bar in accordance with the DPWH standards.

2. SITE PREPARATION AND EARTHWORK

2.1 Site Work

The part of the site occupied by the works shall be cleaned of all trees, roots, vegetation, rocks, boulders etc, and as much surface soil as directed by KEI. Cutting or filling of earth on the site shall be done to lines, levels and slopes as shown on the Drawings. Surplus earth from the excavations within the area, if found suitable may be utilized for filling, but any earth required in excess shall be obtained by the contractor at his own expenses, from dry earth, free from debris, plants and vegetable matter , and other organic materials.

2.2 Excavation

All excavation shall be carried out to the lines and levels, shown on the drawings or as directed by KEI. Excavation work includes necessary diverting of live streams, bailing, pumping, draining, sheeting, bracing and furnishing and placing approved foundation elevation of structures.

2.3 Filling/ Embankment

Prior to construction of embankment, all necessary clearing and grubbing in that area shall be performed in conformity with section 2.1 site work. Embankment and filling shall contain no muck, peat, sod, roots or other deleterious matter. The surface of the existing ground shall be compacted to a depth of 150mm and to the specified requirement of this item.

Each layer shall be level and smoothed with suitable leveling equipment and by distribution of spalls and finer fragments of earth. Filling shall be done in regular horizontal layers not exceeding 150mm in thickness.

3. REINFORCING STEEL

All steel reinforcement shall be accurately placed in the position shown on the drawings and firmly held there during the placing and setting of the concrete. Bars shall be tied at all intersections except where spacing is less than 30mm in each directions, in which case, alternate intersections shall be tied.

Distance from the forms shall be maintained by mean of stays, blocks, toes, hangers, or other supports, so it does not vary from position indicated on the drawing by more than 6mm. Holding reinforcement from contact with the forms

or separating layers of bars shall be precast mortar blocks or other equally suitable devices. Unless otherwise shown on the drawings, the minimum distance between bars shall be 40mm.

Splicing of bars shall be staggered as far as possible and with a minimum separation of not less than 40 bar diameters. Not more than one-third of bars may be spliced in the same cross section. Unless otherwise shown on the drawings, bar shall be lapped a minimum distance of.

Splice Type Grade 40 Grade 60 Not less thanTension 24 bar dia 36 bar dia 300mm

Compression 20 bar dia. 24 bar dia 300mm

In lapped splices, the bars shall be placed in contact and wired together. Welding of reinforcing steel shall not be allowed.

4. CONCRETE WORK

4.1 Mixing of Concrete

Five classes of concrete are provided, namely A,B,C,P and Seal. Each class shall be used in that part of the structure as called for on the drawings. The classes of concrete will generally be used as follows:

Class A. All super structures and heavily reinforced substructures.The important parts of the structure included are slabs,beams,Girders,columns, arch ribs, box culverts,reinforced abutments, Retaining walls and reinforced footings.

Class B. Footings, pedestals, massive pier shafts, pipe bedding and gravityWalls and unreinforced or with only a small amount ofReinforcement.

Class C. Thin reinforced sections, railings, precast R.C. piles andCribbing and for filler in steel grid floors.

Class P. Prestressed concrete structures and members.Seal. Concrete deposited in water

The requirement of materials for mixing shall be referred to item 311,part E of volume II, Blue Book.

As work progresses, at least one sample consisting of three concrete cylinder test specimens, 150 x 300 mm shall be taken for fraction thereof placed each day. The samples shall be tested in accordance with the standard method listed in item 405.36, Part F of volume II, Blue Book.

4.2. Placing of concrete

The concrete shall be placed as nearly as possible to its final position and the use of vibrators for moving of the mass of fresh concrete shall not be permitted.

4.2 Compaction of Concrete

The compaction shall be done by mechanical vibration. The intensity of vibration shall be made so as to visibly affect a mass of concrete with a 3 cm slump over a radius of at least 50 cm.

4.3 Constructing Joints

Concreting shall be carried out continuously to predetermined construction joints, in position shown on the drawings or as may be approved by the consultant.

4.4 Curing

Concrete shall after being placed be suitably protected during the first state of hardening from the harmful effects of sunshine, drying winds, heavy rain, surface water shocks. Concrete made with normal cement shall be prevented from drying out for not less than 7days by application of water.