Work Method Statement for Plain and Reinforced Cement Concrete PCC and RCC

Srinivasan

Administrator
Sep 7, 2017
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mumbai
Work Method Statement for Plain and Reinforced Cement Concrete PCC and RCC

SCOPE
The work of Plain Cement concrete shall consist of laying and compacting of cement concrete on excavated earth in accordance with the requirements of Technical Specifications accordingly to lines, grades and cross sections shown on the drawings. The excavated pit shall be dressed true to line and levels and excavated /unsuitable material shall be disposed off.

CODES / SPECIFICATION
IS 456, IS 516

RESPONSIBILITY
Responsibilities of all concerned is clearly mentioned with respect to overall administration and implementation in the approved Organogram.

MATERIALS TO BE USED
The materials to be used to the work shall be free from organic or other deleterious constituents and are as follows:
Ordinary Portland Cement
It is proposed to use Ordinary Portland Cement of 43 or 53 Grade. The cement shall be procured from reputed manufactures in bags of 50 kg each. The cement shall be stocked at raised platform in covered Cement Godown to protect it from moisture, sun and rain etc. The consumption of cement shall be done on first-in-first-out basis.
Testing of cement shall be done on regular basis to ensure quality as per requirement.
Crushed Stone Aggregates of various sizes and gradation
Coarse Aggregates shall be of clean, hard strong, dense, non-porous crushed stone of specified gradation. Initially the aggregates shall be purchased from market and later these shall be produced from Crusher setup for the project.
The aggregate shall be tested for all physical properties before incorporation in work.
Natural Sand
The Fine Aggregate shall consist of clean, hard, strong and durable pieces o crushed stone or natural sand from river bed. It shall be tested for Fineness Modulus, Silt Content, etc. before using in the works.

SAFETY REQUIREMENT
As per the requirement and the direction of HSE Officer.

DEPLOYMENT OF EQUIPMENT
As per the requirement and the direction of Project Manager.

DEPLOYMENT OF MANPOWER
As per the requirement and the direction of project manager.

IMPLEMENTATION

Mix Design:
Well before proposed start date for RCC works, Mix Design for all grades of concrete to be used in works shall be conducted in Field Laboratory as per approved Technical Specifications. The Mix Design shall be conducted in the presence of ADPL representatives. The Design Mix results shall be submitted to Structural Consultant for approval.
Alternately if the concrete is procured from RMC manufacturers the mix design furnished by them shall be reviewed by ADPL and finally approved by Structural Consultant.

Construction Operations:
Excavation dimension must be checked before start of P.C.C. and necessary shuttering must be done, if required.
Remove all loose earth from foundation pits before placing of P.C.C.
Ensure that measurement boxes are ready before starting this activity.
Take care to sprinkle water and ram manually in foundation pit before placing concrete.
Ensure availability of chute, panja, koba, etc before start.
Compaction of P.C.C. should be properly done to get smooth even levelling course. Loose coarse aggregate can be picked up from the surface.
The dimension of excavation has to be checked before start of PCC and necessary shuttering to be done if required.
Proper “thiyas” for level to be taken before start of work.


SCOPE / PURPOSE
The work of Reinforced Cement concrete shall consist of laying and compacting of cement concrete in structures in accordance with the requirements of Technical Specifications accordingly to lines, grades and cross sections shown on the drawings.

REINFORCED CEMENT CONCRETE.
CODES / SPECIFICATION

IS 456, IS 10262 & SP23

RESPONSIBILITY
Responsibilities of all concerned is clearly mentioned with respect to overall administration and implementation in the approved Organogram.

MATERIALS TO BE USED Reinforcement Steel:
Reinforcement Steel

The Reinforcement Steel (HYSD–Fe415 Grade) shall be procured from manufacturers directly. The Reinforcement bars shall be subject to all necessary tests. The bars shall be procured and stacked in central stack yard. The stacking shall be done in such a way that bars do not come in contact with soil.

Cement
It is proposed to use Ordinary Portland Cement of 53 Grade. The cement shall be procured from reputed manufactures. The cement shall be stocked at raised platform in covered Cement Godown to protect it from moisture, sun and rain etc. The consumption of cement shall be done on first-in-first-out basis. Testing of cement shall be done on regular basis to ensure quality as per requirement.

Coarse Aggregates
Coarse Aggregates shall be of clean, hard strong, dense, non-porous crushed stone of specified gradation. Initially the aggregates shall be purchased from market and later these shall be produced from Crusher setup for the project. The aggregate shall be tested for all physical properties before incorporation in work.

Sand / Fine Aggregates
The Fine Aggregate shall consist of clean, hard, strong and durable pieces of crushed stone or natural sand from river bed. It shall be tested for Fineness Modulus, Silt Content, etc. before using in the works.

Other materials
Associated materials and consumables like water for concrete works, binding wire and cover blocks for reinforcement work, supports, nails and shuttering oil for formwork, tools and tackles shall be arranged and checked for conformance to good engineering and accepted standards.
Other materials like PVC/AC pipe for provision of weep holes, compressible filler board for joint between old and new joint, filter media material beneath stone pitching,Concrete Admixtures used as super-plasticizers:

Concrete Admixtures shall be obtained only from the established manufactures with proven track record, quality assurance and testing of concrete.

SAFETY REQUIREMENT
As per the requirement and the direction of HSE Officer.

DEPLOYMENT OF EQUIPMENT
LIST OF PLANT & EQUIPMENT:

  1. Concrete pump with pipeline
  2. Boom Placer
  3. Tower crane
  4. Needle vibrator with needles
  5. Spare vibrating needles
  6. Surface retarder spray
  7. Concrete Bucket (bottom opening, manually operated)
  8. Air Compressor
  9. DEPLOYMENT OF MANPOWER Labour for each placement point pump operator
  10. Concrete Vibrating masons
  11. Khalasis at placement point
  12. Pipeline Khalasis
  13. Surface retarder sprayers
  14. Carpenters
  15. Unskilled
  16. IMPLEMENTATION
Concrete Design Mix (IS 10262, IS SP 23) and IS 456)
  • Well before proposed start date for RCC works, Mix Design for all grades of concrete to be used in works shall be conducted in Field Laboratory as per approved Technical Specifications. The Mix Design shall be conducted in the presence of ADPL representatives. The Design Mix results shall be submitted to Structural Consultant for approval.
  • Alternately if the concrete is procured from RMC manufacturers the mix design furnished by them shall be reviewed by ADPL and finally approved by Structural Consultant.The Concrete shall be produced as per approved Mix Designs.
  • Admixtures such as super-plasticizers for concrete may be used without exceeding specified limit prescribed by the manufacturers, as the selection of appropriate concrete admixtures is an integral part of the mix design.
  • The production of concrete shall be done with Concrete Batching and Mixing plant of required capacity. In no case shall mixing be done for less than 2 minutes and shall be transported through transit mixers and placed at the work site through crane and bucket or concrete pumps or manually depending upon quantity of concrete to be handled, lift of concrete and thickness of concrete to be done.Transportation of concrete shall be done in transit Mixers.
  • The RCC shall be done throughout the length and width of structure to be constructed and shall conform to specified levels and grade providing firm foundation and level bed.
  • Appropriate number of labourers shall be engaged to lay concrete and vibrators shall be used to have a uniform, homogeneous and compacted surface. Concrete shall not be freely dropped into place from a height exceeding 1.5m to avoid segregation of material.
  • Casting of structures shall be done by placement of shuttering for foundation in line and level followed by reinforcement binding and concreting. All these works shall be executed as per the procedures and norms already laid down herein above.
  • Construction Joints – Concrete shall be done with construction joints as suggested by the Structural Consultant.
  • Other Activities: Curing

One or a combination of the following curing methods can be adopted depending on site conditions, availability of curing materials, type of job, economics etc. :
  • Methods to prevent loss of water in concrete during the early stage of hydration by ponding, water spraying or saturated wet coverings.
  • Methods to prevent loss of water in concrete by sealing the exposed surface i.e. covering the exposed surface with sheets of plastic or other impervious materials, applying membrane forming compounds etc.
  • The curing period in ambient temperatures above 20o C should be for minimum 7 days, or the time necessary to attain 70 0/ of the specified compressive strength.
  • The use of curing compounds are useful on vertical surfaces, or in the event of water shortage.