undefined | unit 6 specifications

EEEC

Unit - 6

Specifications

Q1) Explain what do you mean by specification, Explain in detail. Types of specifications in detail.

A1) Specifications

It can be defined as finishing detailed information about qualities of material, their property proportion in which they are to be mixed. Specification includes the provision of overall information such as description of all workmanship, material and method of working to complete engineering project.

Purpose of specification:

Specifications help to decide cost of overall quality of work.

It also required to describe quality and quantity of different materials required for different construction work.

It is also necessary to specify material tools and plants to be engaged in work

It is essential contract document and it require for arbitration

As the cost of work is directly related to work.

Types of Specification

1. Brief specification

2. Detailed specification

a) General specification

b) Technical specification

c) Standard specification

Q2) Explain types of specifications in detail.

A2) 1. Brief specification:

These are the specification that describe briefly the term of construction and are useful to quantity survey in preparing estimate of work

Without going through lengthy procedure only general information of quantities of material nature and class of work can be known from brief specification.

2. Detailed specification:

Detailed specifications are the part of contract document detailed specification foe different items or prepare separately

Physical chemical electrical test to be conducted to ensure material quantity are also mention in it

Type of machinery tools plants and methods of execution is also mention

Specification is prepared by state government agencies such as PWD and publish in form of booklet named as standard specification

3. Detailed specification are classified as

1) General specification:

The general provisions which are known as condition of contract are applicable to the work as whole. The conditioning governing the contract are mention in such document and have been already explain

2) Technical specification:

In technical provision the detailed are regards desired quality of finish product item of construction are clearly specify and arrangement for inspection and testing to be carried out during the constructions stage to ensure the desired quality and workmanship is also included into technical specifications.

In general, it includes Specification related to material to workmanship For performance For proprietary commodities

3) Standard specification:

These are drawn up by engineering department for different material this saves valuable time labor stationary expenditure and completes work with less time.

The booklet is also called as red book due to its red cover.

Q3) Explain what is requirement and importance of specification.

A3) Requirement and Importance of Specification

Specification should be clearly understood by contractor supervisor staff workman etc.

Wording

Language

Dual meaning

Information

Practical consideration

Use of abbreviation

Fairness

Wording:

As the specification from important of contract document and very useful during execution of the work they should be described in simple concise correctly worded

2. Language:

Specification should follow rules of grammar the style and tense should be maintain same throughout

3. Dual meaning:

The wording of sentence should convey single meaning and dual meaning sentences are avoided

4. Information:

Specification of different item should furnish the exact required information.

5. Practical consideration:

The specification should not be two lengthy and theoretical but should be written by taking all practical difficulties of contractor.

6. Use of abbreviation:

To avoid lengthy description, correct abbreviation should be use to describe specification

7. Fairness:

The specification should be balance and fair to be both owner and contractor.

Q4) Explain process for foundation in detail.

A4) Excavation for Foundation:

Site clearance: Before earthwork is started, whole area is shall be cleared of grass, roots of trees and all obstructions.

Line out: The centre line of proposed structure is marked on plot shown on drawing with correct dimensions of plan and excavation is started.

Excavation: It is carried out to exact dimension (LXBXH) as indicated in drawing.

Disposal: The excavated material should be disposed off away from site and should not be nearer than 1.5m from outer edge of excavation. Engineer-in-charge has responsibility to dispose of excavated material by dumper or other means of transportation.

Dewatering: The excess quantity of water in the trenches should be removed by pumping or any other method. The trenches water replaced with the ramming of the soil.

Shoring: Shoring It is important to provide shoring to sides of excavation to avoid them from collapsing.

Protection: All excavated area should be properly closed and marked with red light to avoid accidents during night.

Backfilling: After ending foundation concrete work, shoring should be removed and space between foundation and sides of excavation shall be refilled to original ground level.

Mode of measurement and payment: Measurement is done in terms of cubic meter of excavation. No payment should be made for excess work carried out by contractor. Payment is depending on type of strata.

Q5) Explain burnt masonry first class in cement mortar.

A5) Burnt brick masonry first class in cement mortar

Materials:

Brick: Bricks should be first class of standard specification. It should be of uniform, regular shape, size and color and well burnt. The edges should be sharp, straight and at right angles free from defects with a frog of 10mm depth on one of its flat surfaces. When one brick is struck on other brick then it produces ringing sound. The size of brick (IS type) should be 19cm x 9cm x 9cm. and it should not absorb more than 20% of water of its dry wet.

Cement: Cement used should be OPC. The cement should measure on weight basis and in whole bags, each bag weighing 50 kg which is equal to 35 liters in volume. Fine aggregates: It should be either natural river sand or broken stone satisfying all IS requirements. They should be clean, strong, and hard. Particle sizes should be 5mm maximum.

Water: Water to be used should be potable. It should be free from oils, acids, alkalis, salts.

b. Preparation of cement mortar: Cement and sand should be mixed first in dry condition in predetermined proportion by volume and then just sufficient quantity of water should be added to it and then turned upside down and forward direction till a homogeneous mass of cement mortar is obtained.

c. Brick lying: Brick firstly thoroughly soaked in water for 2 hours before used in masonry, so that it should absorb water.

Q6) Explain mild steel bar reinforcement for RCC work.

A6) Mild Steel Bar Reinforcement for RCC Work

Material: Mild steel - Such bars used as reinforcement for RCC work should conform to bureau of ISI of 423 of 1960 and should be tested and duly certified by competent authorities of test house. The cost of test should be borne by contractor. The M.S. bars should be free from dirt, dust, rust, OU, Paint and these bars should be protected from corrosion and rust.

Fabrication of steel: Before fabricating, all steel reinforcement shall be cleaned thoroughly of all dust, dirt. All reinforcing steel should be bent cold to dimension shown in plan. During bending material should not be injured.

Placing of reinforcement: All reinforcing bars should be placed in correct position with exact spacing and cover as indicated on drawings. Binding wires of 1.22 or 1.63mm diameter should be used for fastening at intersection points or it may be spot welded.

Inspection of reinforcement: No concreting should be carried out till the entire reinforcement has been inspected and approved by Engineer-in-charge, writings.

Test certificate: If the reinforcing steel is brought by contractor, he has to produce a certificate from authorized test house regarding its suitability for the work.

Mode of measurement and payment: All steel reinforcement should be measured in quintal and should be as shown on reinforcement details of drawings. The length should be measured correct to two decimal places in meters and weight measured correct to 0.1kg and payment made at the agreed rate.

Q7) Explain RCC work for slab.

A7) RCC work for slab:

Materials

Cement: Cement used should ordinary port land cement conforming to IS 269 1958. The cement should measure on weight basis and in whole bags, each bag weighing 50 kg which is equal to 35 liters in volume.

Sand: It shall be formed from burning of first-class brick. They should be clean, strong, hard. Particle sizes should be 5 mm maximum.

Coarse aggregate: It should be broken/ crushed from hard stone obtained from approved quarry. It should be strong, hard, dense, clean and durable. It should clean from dirt and dust. The aggregate should be well graded to obtain a compact and dense volume of concrete with workability.

Water: Water used should be free from injurious quantities of deleterious materials like oil, acids, alkalis, salts.

b. Proportion of mix: The cement, sand, aggregate is mixed either on volumetric or weight basis in proportion of 1:2:4.

c. Mixing: The concrete should be prepared in mechanical mixer the drum being rotated at least for 2 minutes. The water cement ratio should be 0.55 or as directed by engineer – in

d. Form work: The form work conforms to pare 7.2 of IS 456 charge of 1957.

e. Placing of concrete: Before placing of concrete, entire formwork and reinforcement is checked by engineer - in charge. The concrete is then laid to required thickness throughout as shown in drawing. Entire work is to be completed in one continuous operation. Labors should not be allowed to cross over freshly laid concrete.

f. Compaction: Compaction should be carried out either manually by road, or mechanical vibrator so as to get homogeneous dense mass of concrete without any cavities.

g. Curing: Lime concrete layers should be kept wet at least for two weeks after it is laid in position only clean water be used for curing.

h. Mode of measurement and payment: The mode of measurement of should be as per I.S.1200 of 1965 in cubic meters of slab laid to correct thickness as shown on drawing. The contractor should be paid at the agreed rate on per cubic meter basis.

Q8) Explain general specification for second class building in detail.

A8) General specification for second class building:

1. Foundation and plinth: Foundation and plinth shall be of 1" class brickwork with lime mortar over time concrete.

2. Damp proof course: DPC shall be 2cm thick cement concrete 1: 2 mixed with 1 kg per bag of cement

3. Super structure: Super structure shall be second class brickwork in lime mortar.

4. Roofing: Roof shall be of R.B. slab with 7.5 cm lime concrete terracing above veranda roof may be of A.C. sheet.

5. Flooring: Floors shall be 2.5 cm cement concrete over 7.5 cm.

6. Finishing: Inside outside walls should be plastered with cement mortar 1:6.

7. Doors and windows: Door frame shall be RCC with well seasoned Sal wood, glazed or partly glazed as required, fitted with iron fittings.

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