Requirements to works and structural materials

Concrete and reinforced-concrete structures

 

The supports of the gantries shall be made of concrete similar to concrete of В40 class (strength) and F100 class (frost resistance), in accordance with SNiP 2.03.01-84 "Concrete and reinforced-concrete structures".

 

The following materials shall be used for reinforcement of supports of the gantries:

а) rod-type hot-rolled reinforcing steel,with parameters similar to:

· Steel of AV class, grade 23X2G2T as per DSTU 3760-98;

· Reinforcement bars of A800S class as pr DSTU 3760-98;

б) standard reinforcing wire, with parameters similar to wire of Вр-I class as per GOST 6727-80.

The supports under the equipment shall be made of concrete similar to concrete of В15 class(strength) and F100 class (frost resistance), in accordance with SNiP 2.03.01-84 "Concrete and reinforced-concrete structures".

 

The following materials shall be used for reinforcement of supports:

· Rod-type hot-rolled reinforcing steel, with parameters similar to steel of AI class as per GOST 5781-82. The chemical composition of reinforcing carbon steel shall correspond to the chemical composition of steel of St3 grade as per GOST 380-94, reinforcement class is A240S as per DSTU 3760-98.

· Rod-type hot-rolled reinforcing steel,with parameters similar to steel of 25G2S grade as per GOST 380-94,class Alll as per GOST 5781-82, reinforcement class A400S as per DSTU 3760-98.

 

The elements of cable trays shall be made of concrete similar to concrete of В15 class (strength) and F100 class (frost resistance), in accordance with SNiP 2.03.01-84 "Concrete and reinforced-concrete structures".

 

The following materials shall be used for reinforcement:

· Rod-type hot-rolled reinforcing steel,with parameters similar of steel of Al class as per GOST 5781-82. The chemical composition of reinforcing carbon steel shall correspond to the chemical composition of steel of St3 grade as per GOST 380-94, reinforcement class is A240S as per DSTU 3760-98.

· Standard reinforcing wire, with parameters similar to wire of Bp-l class as per GOST 6727-80.

 

Metallic structures

 

The steel structures shall meet the requirements of GOST 27751-88 (ST SEV384-87) "Reliability of building structures and foundations. Basic provisions for calculation".

 

The basic requirements to the materials shall meet GOST 27772-88.

 

The rolled metal items shall be made of carbon steel that meets the requirements of DSTU 2651-94 (DSTU 2651:2005 (GOST 380-2005)).

 

The structural shapes shall be made of steel of grades similar to S235, S245, S255, S345 as per GOST 27772-88.

 

The shape, dimensions, limit values of the rolled metal items shall meet the following requirements:

 

· GOST 8509-93: for angle bars with equal flanges;

· GOST 8510-86: for angle bars with unequal flanges;

· GOST 8239-89 for I-beams;

· GOST 26020-83 for I-beams with parallel faces of flanges;

· GOST 8240-97: for channel bars;

· GOST 19903-74: for rolled sheets;

· GOST 2590-88: for round steel.

 

Corrosion protection

 

All supporting metallic parts of the equipment to be supplied shall be hot-dip galvanized; all cabinets supplied along with the equipment shall be made of corrosion-resistant material.

 

 

All metal structures shall be hot-dip galvanized to provide corrosion protection. Zinc consumption shall be not less than 600 g per 1 m² of surface.

 

The thickness of zinc coating of fasteners, including threaded bolts shall be not less than 45 microns.Threads of nuts shall not be galvanized. Fasteners of gantries shall be hot-dip galvanized.

 

Drilling, punching, cutting and bending of all steel structures manufactured at the factory, shall not result in any deviations, which could complicate installation of the gantries at the site. Protecting slings shall be used for off-loading and erection. Galvanized steel work, stored at the works or on site shall be stacked to provide adequate ventilation of all surfaces to avoid wet storage staining (white rust).

 

Except where specified to the contrary, all cast iron and steel materials used in construction shall be galvanized. Galvanizing shall be applied by hot dip process, not less than 610 g/m² for all parts except steel wire or bolts where zinc coating may be 300 g/m2. The zinc coating shall be smooth, clean and of uniform thickness and free of defects. The preparation for galvanizing and the galvanizing itself shall not adversely affect the mechanical properties of the coated materials.

 

The preparation for galvanizing and the galvanizing itself shall not adversely affect the mechanical properties of the coated materials. All drilling, punching, cutting and bending of parts shall be completed, and all burrs shall be removed before the galvanizing process is applied.

 

Painting

 

The Contractor shall deliver necessary paint and varnish materials, which will be, if necessary, used for painting of all electrical equipment damaged during transportation or installation.

 

For the metal structures of the Outdoor Switchgear, which will be welded at site, the corresponding temporary corrosive protection, performed at factory for transportation and installation shall be applied.

 

The Contractor shall provide sufficient measures for surface treatment and painting, including full information about primer materials and painting procedure.

 

The Contractor shall guarantee that materials, methods and procedures, which he suggests to use, are in accordance with the safety regulations and do not pollute the environment.

 

The Contractor shall submit the complete list of materials, including information about volatile content, type of remover, quantity of components, coating type, intervals between coating and amount of coating, toxic properties of materials, expiration date and service life time.

 

Before applying any coating, all surfaces shall be prepared. Such preparation includes cleaning, drying and other processing to guarantee that the coating is applied to the corresponding base. Stainless steel parts are not subject to painting or galvanizing.

 

Deviation tolerances of building structures

 

The allowable tolerances of deviations of the building structures shall not exceed those in the table below:

 

№	Name of structures	Deviations	Deviation value
	Bases	Shortage to designed level with mechanized ground development	5-7 cm
	Foundations	a) offset of foundation axis relative to layout axes	+10mm -10 mm
b) displacement of planes and crossing lines from vertical	+20mm -20 mm
c) displacement of horizontal planes over the plane of adjusted area	+20mm -20 mm
d) local deviations in dimensions of cross-section	+6 mm -3 mm
	Stands	a) ultimate vertical deviation	+15mm -15 mm
b) inclination over ground surface	Max. 10 mm per 1 m of length
c) level difference of tops of adjacent stands	3 mm
	Metallic structures	a) clearance between plate and metal ruler	1,5 mm
b) deviation of edge line of sheet articles when welding:
· In butt joint	2 mm
· lapped	5 mm
c) deviation in bending. A gap between template and rolled:
· cold	2 mm
· hot	3 mm
d) displacement of rod layout axes in lattice structural items	3 mm
	Masonry works	а) deviation from design values on: · thickness	+15 mm
· cutting marks	15 mm
· partition wall width	-20 mm
· opening width	+20 mm
· displacement of axes of adjacent window openings	20 mm
b) deviation of brickword rows from horizontal per 10 m of length	20 mm
c) irregularities on the vertical surface of brickwork revealed by placing a 2-meter plank	10 mm

 

Shipment and transportation

 

During transportation of construction-purpose cargos, the Contractor shall meet the requirements of SNiP III-4-80, Part III "Rules of performance and acceptance of works", Chapter 4 "Safety precautions in construction", DBN A.3.1-5-96 "Organization of construction production". Transportation, storage and warehousing of materials, structures and equipment are organized as per DBN G.1-4-95 "Rules of transportation, storage and warehousing of materials, products, structures and equipment in construction".

 

Transportation of inflammable cargos shall be performed by the means of transportation equipped as per the rules and instructions for such cargo category.

 

Transportation and temporary storage of structures, products and equipment in the erection area shall be carried out according to the requirements of specifications for such structures (products), while for the non-standardized structures (products) it is necessary to meet the following requirements:

 

· Structures shall be placed in a position corresponding to their design, and if this condition cannot be met, structures shall be placed in the position convenient for transportation to erection site, taking into account that thei strength and durability shall be maintained;

· Outstanding pieces of reinforcement bars and outstanding parts shall be protected against damage;

· Small parts for installation joints shall be attached to the shipped elements or sent simultaneously with structures in the container with labels, identifying parts names and their quantity. These parts shall be stored under canopy;

· Fastening parts shall be stored indoor, sorted by types and makes; bolts and nuts shall be sorted by classes of durability and diameters.

 

The Contractor shall provide transportation, unloading and safe storage of all structures, equipment and materials necessary for construction of the substation. At the same time:

 

a) transportation of heavy, long and large-sized cargos shall be provided using specialized means of transportation. To avoid rolling or falling over during vehicle movement, the cargos shall be placed and fixed on vehicles according to specifications of loading and fastening of the given type of cargo;

 

b) insulators shall be transported packed in boxes or on grates. Transportation of insulators in bulk is for Tenderden;

 

в) in necessary cases, dump trucks shall be equipped with special stoppers in order to support the tipper body in the lifted position.

 

During storage, the structures shall be sorted by types, and stacked taking into account the sequence of installation.

 

Marking of cargo containers shall meet the requirements of GOST 14192-96.

 

Handling of dust-like materials (cement, lime, plaster) shall be carried out in a mechanized way. As an exception, cement unloading handworks are allowed at its own temperature not exceeding 40°С.

 

Before loading or unloading of precast reinforced-concrete structures, the installation ears shall be examined, cleared from grout solution or concrete and, if necessary, corrected without damage to the structure.

 

The Contractor shall independently perform inspection of road sections and bridges, along which the equipment and building structures will be transported.