Specification Cost of Material Unit 2 Part 2

Que2.11. What’s specification and its objects? Also explain its  types. 

Answer  Specification A specification is a statement of particulars.  Construction specifications may be defined as written instructions   identifying( or limiting) and describing in detail the construction  work to be accepted.  Objects Following are the objects of specification 

1. Contract Document Specifications serve as a contract document  between the  proprietor and the contractor, limiting and describing their   liabilities. 

2. companion to stab Specifications enable the estimators of the  contractors to arrive at a fair price for the work involved. 

3. Guide to administrators Specifications serve as a  companion for the  fabrication and installation of accoutrements  and  outfit.  Types of Specification Following are the two types of specification 

1. General Specifications 

i. In general specifications, nature and class of  workshop and names of  accoutrements  that should be used are described. 

ii. Only a brief description of each and every item is given. It’s useful for  estimating the  design. 

iii. The general specifications don’t form a part of contract document. 

2. Detailed Specifications 

i. The detailed specifications form a part of a contract document. 

ii. They specify the  rates, amounts and proportions of accoutrements  and  the  system of medication and  prosecution for a particular item of  workshop  in a  design. 

iii. The detailed specifications of the different  particulars of the work are  set  independently and they describe what the work should be and how they  shall be executed. 

iv. While writing the detailed specifications, the same order sequence as  the work is to be carried out is to be maintained. 

Que2.12. bandy the  significance of detailed specification. 

Answer  significance of Specifications Following are the  significance of  specifications 

1. The cost of a unit  volume of work is governed by its specifications. 

2. Specification of a work is  needed to describe the quality and  volume  of different accoutrements   needed for a construction work and is one of  the essential contract documents. 

3. This also specifies the workmanship and the  system of doing the work. 

4. A work is carried out according to its specification and the contractor is  paid for the same. Any change in specification changes the  proffered  rate. 

5. As the rate of work is grounded on the specification, a contractor can  calculate the rates of  colorful  particulars of  workshop in tender with his  procurement rates of accoutrements  and labour. therefore tender rate without  specification of  workshop is  unwarranted, deficient and invalid. 

6. Specification is necessary to specify the  outfit tools and  shops to  be engaged for a work and  therefore enables to  land them beforehand. 

7. The necessity of specification is to  corroborate and check the strength of  accoutrements  for a work involved in a  design. 

Que2.13. Write down a detailed specification of channel in  excavation in foundation. 

Answer  Channel in Excavation in Foundation Following are the points  consider in excavation in foundation 

  1. Excavation  Foundation  fosses shall be dug out to the exact  range of foundation  concrete and the sides shall be  perpendicular. , the sides  If the soil isn’t good and doesn’t permit  perpendicularsides.should be  leaned back or  defended with timber shoring. 
  2. iii. shoveled earth shall not be placed within 1 m of the edge of the   fosse . 

2. Finish of Trench

 i. The bottom of foundation  fosses shall be  impeccably leveled both  longitudinally and  obliquely and the sides of the  fosse  shall be  dressed  impeccably  perpendicular from bottom up to the least consistence of  loose concrete so that concrete may be laid to the exact  range as per  design. 

ii. The bed of the  fosse  shall be  smoothly  doused  and well rammed. redundant  digging if done through mistake shall be filled with concrete at the   expenditure of the contractor. 

iii. Soft or  imperfect spots shall be dug out and removed filled with concrete  or with stabilized soil. , these should be If  jewels or boulders are  set up duringexcavation.removed and the bed of the  fosses shall be leveled and made hard by  consolidating the earth.  Foundation concrete shall not be laid before the  examination and  blessing  of the  fosse  by the  mastermind- in- charge. 

3. Water in Foundation Water, if any accumulates in the  fosse ,  should be bailed or pumped out without any  redundant payment and  necessary  preventives shall be taken to  help  face water to enter  into the  fosse .

4. fosse Filling After the concrete has been laid masonry has been  constructed the remaining portion of the  fosses shall be filled up  with earth in layers of 15 cm and  doused  and well rammed. 

5. dimension 

i. The  dimension of the excavation shall be taken in cu m( cu ft) as  for blockish  fosse  bottom  range of concrete multiplied by the   perpendicular depth of foundation from ground  position and multiplied, by the  length of  fosses indeed though the contractor might have  shoveled   with  leaning side for his convenience. 

ii. Rate shall be for complete work for 30 m lead and1.50 m lift, including  all tools and  shops  needed for the completion of the  workshop. 

iii. For every  redundant lead of 30 m and every  redundant lift of1.5 m separate  redundant  rate is  handed. 

Que2.14. Write down a detailed specification of cement concrete  1 2 4. 

Answer  Detailed Specification of Cement Concrete 1 2 4 Following are  the point consider in specifications of cement concrete 1 2 4 

1.Accoutrements  Aggregate shall be of invert accoutrements  and should be clean,  thick,  hard, sound, durable,non-absorbent and able of developing good  bond with mortar. 

ii. Coarse  total shall be of hard broken gravestone of  determinedness or  analogous  gravestone, free from dust, dirt and other foreign matters. 

iii. The gravestone cargo shall be of 20 mm size and down and all should be  retained in a 5 mm square mesh and well graded  similar that the voids do  not exceed 42 per cent. 

iv. For  erecting work 20 mm hand and for road work and mass work 40  to 60 mm hand may be used.  Fine  total shall be of coarse beach  conforming of hard, sharp and  angular grains and shall pass through screen of 5 mm square mesh. 

vi. Cement shall be fresh Portland cement of standard ISI, specifications,  and shall have the  needed tensile and compressive stresses and  fineness. 

vii. Water shall be clean and free from alkaline and acid matters and  suitable for drinking purposes. 

2. Proportion 

i. The proportion of concrete shall be 1 2 4 as cement beach gravestone  cargo by volume unless  else specified. 

ii. minimal compressive strength of concrete of 1 2 4 proportion shall  be 140 kg per sq cm( 2000 lbs/ sq in) on 7 days. 

iii. Gravestone  total and beach shall be measured by volume with boxes. 

iv. Cement need not be measured by box, one bag of cement( 50 kg)  should be considered as 1/ 30 cum.  Size of measured box may be 30 cm × 30 cm × 38 cm or 35 cm × 35 cm  × 28 cm original to content of one bag of cement. 

3. Hand Mixing  Mixing shall be done in masonry platform or  distance iron charger.  

ii. For concrete of 1 2 4 proportion, first two boxes of beach and one bag  of cement shall be mixed dry completely and  also this dry  blend of  cement and beach shall be placed over a  mound of 4 boxes of gravestone  total and the whole mixed dry turning at least three times to  have  invariant  blend.  iii. Water shall  also be added  sluggishly and gradationally according to water cement rate with a water- can while. 

iv. The whole shall be mixed completely turning at least three times to  give a  invariant concrete. 

4. Machine mixing  Stone cargo beach and cement shall be put into the cement concrete  mixer to have the  needed proportion. 

ii. Mixer, the machine shall  also be revolved to  blend accoutrements  dry and   also water shall be added gradationally to the  needed  volume. 

5. Formwork  Formwork centering and shuttering shall be  handed as  needed, as  per standard specifications before laying concrete to confine to support  or to keep the concrete in position. 

ii. The inner  face of shuttering shall be  waxed to  help concrete  sticking to it. 

iii. The base and formwork over which concrete to be laid shall be  doused   by  smattering water before concrete is laid. 

iv. Forms shouldn’t be removed before 14 days in general, side forms  may  still be removed after 3 days of concreting. 

6. Laying  Concrete shall be laid gently( not thrown) in layers not exceeding  15 cm and compacted by cascading with rods and tamping with  rustic   tampers or with mechanical  wobbling  machine until a  thick concrete  is  attained. 

ii. Concrete shall be laid continuously, if laying is suspended for rest or  for the following day the end shall be  leaned at an angle of 30 ° and  made rough for  farther jointing. 

iii. When the work is  proceeded , the  former  graded portion shall be  planed,  gutted and  doused  and a grout of neat cement shall be  applied and the fresh concrete shall be laid. 

iv. For  consecutive subcaste the upper subcaste shall be laid before the lower has  set. 

7. Curing After about two hours laying when concrete has begun to  harden, it shall be kept damp by covering with wet gunny bags or wet  beach for 24 hours, and  also cured by  submerging with water making  slush  walls7.5 cm high or by covering with wet beach or earth and kept damp  continuously for 15 days.

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