Comprehensive Procedure for RCC Concrete: Supervision, Documentation, and Quality Assurance

Purpose of Procedure for Rcc Concrete

The purpose of this procedure is to provide a methodology for active surveillance of various activities involved in the supervision of R.C.C.work at the site and to ensure that (RCC CONCRETE )

Why Required of RCC Concrete?

1. Shuttering is placed as per correct line & level
2. Reinforcement is laid on as per approved Drawing\ BBS \ Specifications
3. Proper procedures are followed for R.C.C. work
4. Documents are generated to quantify the actual job done.

Scope of RCC Concrete

This procedure covers supervision and record-keeping methods for RCC, which include.

1. Top & a bottom level of RCC.
2. Proportioning of a concrete mix as per grade of Concrete.
3. Preparation of pour card and adhering to prescribed quality standards.

Reference Documents Procedure for RCC Concrete

1. CPWD Specification
2. AFC drawing
3. SOR

Procedure for RCC Concrete Detailed Action Plan

Here, the plan of RCC concrete are as follows.

A. Procedure for RCC Concrete: Materials

1. Testing of materials; for cement manufacturer test certificate shall be submitted for each batch of cement. In the case of MTC, correlation is not done; the same shall be tested at an approved laboratory. RCC shall be used as per SOR item & AFC drawings.
2. Coarse aggregate shall be tested at a field laboratory or an approved laboratory, and gradation of coarse aggregate shall conform to IS:383. Crushing value, impact value, abrasion value, flakiness index of coarse aggregate shall be tested at field laboratory or approved laboratory per IS 2386. The frequency of testing shall be as per QAP. (Replace IS: 8112 by IS 1489 where PPC is used installed of OPC)
3. Fine aggregate shall be tested at a field or an approved laboratory. Gradation of fine aggregates shall conform to IS:383 & shall be tested in an area. Presence of harmful material shall he tested at a laboratory. Frequency of testing shall be as per QAP.
4. For reinforcement steel., the manufacturer test certificate shall be submitted.

B. Procedure for RCC Concrete: Mix Design:

1. Before the establishment of the design mix, all the materials such as CA, FA cement, etc. shall be tested.
2. Design stipulation such as water-cement ratio, degree of quality control, minimum cement content, workability, etc. shall be considered as stated in the contract document.
3. In case of change of design stipulation or change of source of ingredients using for concrete re-design mix will be done.
4. The trial mix shall be taken at the site condition for the design mix.

C. Procedure for RCC Concrete: Mixing of Concrete

1. For weight batching in a plant, the entire ingredient shall be poured by weight. Cement shall be stored in cement through a bucket elevator. Water shall be measured in volume.
2. The admixture shall be measured by weight. During hot/cold weather, the mixing shall be as per IS:7861.

D. Procedure for RCC Concrete: Transportation, Placing & Compaction:

1. Concrete shall be transported from batching plants to pouring locations through transit mixers. Concrete shall be poured immediately after its transportation to the working site.
2. For concreting in-depth, chutes shall be used. The vertical fall should not be more than 1.5m in height.
3. Immediately after pouring of Concrete in the formwork, it shall be compacted by using mechanical vibrating equipment.
4. Immersion type vibrator shall be inserted in a vertical position, and care should be taken so that it does not over or under-vibrate.
5. At the time of transportation and placing of concrete, all the precautionary measures must be taken to avoid any sort of deterioration in quality.
6. Care shall be taken to ensure adequate vibration, hounding, and mounding of Concrete between the succeeding batches. Before placing of Concrete, the area shall be cleaned properly.
7. Concrete shall be deposited as near as practicable in its final position to avoid re-handling.
8. Concrete shall not be started unless electrical conduits, pipes fixtures, etc. whenever required are laid before concreting all metal inserts anchor bolts pipe sleeves, etc. shall be fixed as per relevant drawing and that shall be checked W.R.T. its lines & levels.

E. Procedure for RCC Concrete: Joints

1. Construction joints shall be provided as shown in drawings or as decided by SGS. As far as possible, the number of construction joints has to be minimum.
2. The joint shall be formed 100-150mm below the lowest soft of the beam. The joint in beam & slab shall be vertical within 1/3rd-1/4th of the span with an approved stop board at the time of the resume of the next work.
3. The hardened surface shall be cleared off foreign materials, roughened property & wetted by pouring cement slurry or mortar.

F. Procedure for RCC Concrete: Curing

1. Concrete shall be cured by keeping it continuously moist wet for a specified period to ensure complete hydration of cement & its hardening.
2. Curing shall be started after 8 hrs of placement of Concrete in normal weather in hot weather after 4hrs.
3. The exposed surface of Concrete shall be maintained continuously in a damp or wet condition for at least for the first 7 days after placing Concrete.
4. Curing shall be done 10 days for dry /hot weather conditions in case of mineral admixture is used curing may be extended to 14 days.

G. Procedure for RCC Concrete: Strength Test of Concrete

1. Samples in the form of 15 cm x I5cm x 15cm cubes shall be taken from fresh
2. Concrete, cured and tested at 7 days & 28 days in accordance with IS 516.
3. The required strength of cubes depending on the grade of Concrete will be as per IS 456.
4. The Concrete shall be deemed to comply with the strength requirement if it satisfies the acceptance criteria as per IS:456.

H. Procedure for RCC Concrete: Finishing of Concrete

1. On removal of formwork, all the surface defects observed shall be rectified immediately.
2. The surface of now-shuttered faces shall be smoothened with a wooden float to give a finish similar to that of the rubbed down shuttered faces the top faces of the Concrete intended to be covered with screed or any other work shall be left with a rough finish.

I. Procedure for RCC Concrete: Formwork

1. Forms for Concrete shall be of plywood conforming to IS: 6461 or steel & shall give smooth & even surface after removal thereof.
2. Formwork & its support shall maintain their correct position & shall be of proper shape & profile so that the final concrete structure is within the limits of dimensional tolerance specified in IS: 456.
3. The form shall be true, rigid & adequately braced both horizontally & diagonally. The form shall have smooth and even surface & be sufficiently rigid to carry without deformation.
4. The deadweight of green Concrete, working load, and wind load & also the side pressure the green concrete form joint shall not permit any leakage. The form shall be strong enough to withstand the effect of vibrations.
5. Before re-use, all form shall be thoroughly scrapped, cleaned, examined & whenever necessary shall be repaired & retreated before re-setting.
6. In the determination of time for removal of form, consideration shall be given to the location & character of structure the weather & other condition including the setting & curing of Concrete & material used in the mix.
7. The form shall be removed without shock & the method of form removal likely to cause overstressing or damage to Concrete shall not be adopted.
8. In normal circumstances, form shall he remove below soffits of beams & slabs as per IS: 456.
9. Staging & scaffolding shall be properly designed & steel tubes will be used.
10. For circular shuttering, care shall be taken so that it is supported properly & diameter has been kept accurately.

J. Procedure for RCC Concrete: Reinforcement Steel

1. Before placing the reinforcement steel, the bar bending schedule shall be prepared & got checked by SGS. Reinforcement shall be cut, bend to shape & dimension as shown in BBS / Drawings.
2. All reinforcement shall be fixed in the correct position, as shown in the drawing & shall be properly supported to ensure that displacement will not occur when the Concrete is displaced & completed.
3. Reinforcement bars shall be tied at every intersection. Cover blocks of specified thickness, constructed & cured properly shall be placed in between forms & reinforcement to provide sufficient clearance.
4. In the case of overlapping of two bars, lap length shall be provided as mentioned in the drawing. The lap shall he stagger.
5. In any section, lap should not be more than 50% of the total area. Tolerance of placing of reinforcement shall be as per IS: 456.

Frequently Asked Questions (FAQs)

What Is the Primary Purpose of the Rcc Concrete Procedure?

The primary purpose is to establish a systematic approach for the supervision and documentation of RCC (Reinforced Cement Concrete) work at the construction site. It ensures that the construction process adheres to the specified standards, including the correct placement of shuttering, reinforcement, and adherence to quality control measures.

Why Is Proper Shuttering Important in Rcc Concrete Work?

Proper shuttering ensures that the RCC concrete maintains its intended shape and dimensions. It is crucial for achieving the structural integrity and accuracy of the finished concrete elements, including maintaining correct lines and levels as per approved drawings and specifications.

What Are the Key Components of the Rcc Concrete Procedure?

The key components include:

1. Materials: Testing and verification of cement, aggregates, and reinforcement steel.
2. Mix Design: Establishing and testing the concrete mix according to specified grades and requirements.
3. Mixing: Procedures for accurate weighing and mixing of ingredients.
4. Transportation, Placing, and Compaction: Methods to ensure proper transport, placement, and compaction of concrete.
5. Joints: Guidelines for forming and treating construction joints.
6. Curing: Ensuring continuous moisture to facilitate proper hydration and strength gain.
7. Strength Testing: Procedures for testing concrete strength at specified intervals.
8. Finishing: Techniques for rectifying surface defects and achieving the desired finish.
9. Formwork: Specifications for formwork to ensure smooth and accurate concrete surfaces.
10. Reinforcement Steel: Guidelines for placing and securing reinforcement steel as per design requirements.

How Is Concrete Mix Design Determined?

Concrete mix design is based on the requirements specified in the contract document, including factors such as water-cement ratio, quality control degree, and workability. The mix is tested through trial mixes at site conditions to ensure it meets the desired performance criteria.

What Is the Importance of Curing in Rcc Concrete?

Curing is essential for ensuring the complete hydration of cement and the development of concrete strength. Proper curing prevents premature drying and cracking, ensuring the concrete achieves its intended durability and performance.

How Are Construction Joints Handled in Rcc Concrete Work?

Construction joints are provided to control the flow of concrete and minimize potential issues with continuity. The number of joints is minimized, and their placement is strategically decided based on design requirements. The joints must be properly treated and cleaned before resuming work.

What Tests Are Conducted to Ensure the Quality of Rcc Concrete?

Key tests include:

1. Material Tests: Cement, aggregates, and reinforcement steel are tested for compliance with standards.
2. Strength Tests: Concrete samples (typically 15 cm x 15 cm x 15 cm cubes) are tested at 7 and 28 days for strength as per IS 516.
3. Slump Test: To check workability and consistency of the mix.

How Should Formwork Be Maintained and Reused?

Formwork must be smooth, rigid, and properly braced to ensure accurate dimensions and structural integrity. Before reuse, formwork should be thoroughly cleaned, examined for damage, and repaired as necessary.

What Precautions Are Taken During the Transportation and Placing of Concrete?

Concrete should be transported in transit mixers and placed immediately to prevent setting. Adequate measures are taken to avoid segregation or deterioration of concrete quality. Compaction using vibrators is crucial to remove air pockets and ensure proper density.

How Is Reinforcement Steel Prepared and Placed?

Reinforcement steel is cut and bent according to the bar bending schedule. It must be placed accurately, supported properly to prevent displacement, and tied at intersections. Cover blocks ensure the correct cover thickness is maintained.