Some of the common point that should known by every civil engineer while they working at construction site or about to work. Here we will discuss some of the points.
General notes for civil engineering
Electrical conduits shall not run in column.
- Earth work excavation for basement above 3 m Should be stepped form.
- Any Back filling shall be compacted 95% of dry density at the optimum moisture content and in layers not more than 200mm for filling above structure and 300 mm for no structure.
- F SOLING IS SPECIFIED THE SOLING STONES SHALL BE LAID AT45° TO 60° INCLINATION (AND NOT VERTICAL) WITH INTERSTICES FILLED WITH SAND OR MOORUM.
- Y REPRESENTS TOR STEEL GRADE – Fe-415 OF IS:1786. WITH CHARACTERISTIC YIELD STRENGTH OF 415 N/MM MINIMUM.∅ REPRESENTS MILD STEEL GRADE – 1 OF IS:432 (PART-1)
- ALL REINFORCEMENT SHALL BE FREE FROM MILL SCALES,LOOSE RUST & COATS OF PAINTS, OIL OR ANY OTHER SUBSTANCES.
- BY PROVIDING PROPER COVER BLOCKS, SPACERS, CHAIRS ETC.. ALL REINFORCEMENT SHALL BE PLACED AND MAINTAINED IN POSITION AS SHOWN IN STRUCTURAL DRAWING
- CEMENT SHALL BE 43 GRADE ORDINARY PORTLAND CEMENT CONFORMING TO IS:8112 OR53 GRADE ORDINARY PORTLAND CEMENT CONFORMING TO IS:12269-1987.
- CEMENT SHALL BE STORED IN DRY PLACES ON A RAISED PLATFORM ABOUT 200mm ABOVE FLOOR LEVEL AND 300mm AWAY FROM WALLS.BAGS TO BE STACKED NOT MORE THAN 10 BAGS HIGH IN SUCH A MANNER THAT IT IS ADEQUATELY PROTECTED FROM MOISTURE AND CONTAMINATION.
- WATER USED FOR BOTH MIXING AND CURING SHALL BE CLEAN AND FREE FROM INJURIOUS AMOUNTS OF OILS, ACIDS,ALKALIS, SALTS,SUGAR AND ORGANIC MATERIALS OR OTHER SUBSTANCES THAT MAY BE DELETERIOUS TO CONCRETE OR STEEL. THE pH SHALL BE GENERALLY BETWEEN 6 AND 8.
- CEMENT SHALL BE TESTED FOR ITS SETTING.
- THE INITIAL SETTING TIME SHALL NOT BE LESS THAN 30 MINUTES.
- THE FINAL SETTING TIME SHALL NOT BE MORE THAN 10 HOURS.
- SAMPLES FROM FRESH CONCRETE SHALL BE TAKEN AND AT LEAST A SET OF 6 CUBES OF 150mm SHALL BE PREPARED AND CURED. 3 CUBES EACH AT 7 DAYS AND 28 DAYS SHALL BE TESTED FOR COMPRESSIVE STRENGTH. THE TEST RESULTS SHOULD BE SUBMITTED TO ENGINEER FOR APPROVAL.IF RESULTS ARE UNSATISFACTORY NECESSARY ACTION/RECTIFICATION/REMEDIAL MEASURES HAS TO BE EXERCISED.
- A SET OF CUBE TESTS SHALL BE CARRIED OUT FOR EACH 30 Cum OF CONCRETE / EACH LEVELS OF CASTING / EACH BATCH OF CEMENT.
- WATER CEMENT RATIO FOR DIFFERENT GRADES OF CONCRETE SHALL NOT EXCEED 0.45 FOR M20 AND ABOVE AND 0.50 FOR M10 / M15 CONTRACTOR / MIX DESIGNER TO CARRY OUT THE NECESSARY INITIAL (PRELIMINARY) TESTS.FOR CONCRETE GRADES M20 AND ABOVE APPROVED ADMIXTURE SHALL BE USED AS PER MIX DESIGN REQUIREMENTS.
CONCRETE COVER
- CLEAR COVER TO MAIN REINFORCEMENT IN
- FOOTINGS : 50 mm
- RAFT FOUNDATION.TOP : 50 mm
- RAFT FOUNDATION.BOTTOM/SIDES : 75 mm
- STRAP BEAM : 50 mm
- GRADE SLAB : 20 mm
- COLUMN : 40 mm
- SHEAR WALL : 25 mm
- BEAMS : 25 mm
- SLABS : 15 mm
- FLAT SLAB : 20 mm
- STAIRCASE : 15 mm
- RET. WALL : 20/ 25 mm on earth
- WATER RETAINING STRUCTURES : 20 / 30 mm
- CONTRACTOR SHALL ALLOW FOR INDEPENDENT TESTING OF REINFORCEMENT STEEL FOR EACH DIA OF BAR FOR EVERY 50T AND AT CHANGE OF SOURCE.
- ALL BEAM REINF. TO BE ANCHORED FOR A MINIMUM LENGTH OF 46 x DIA OF BAR INTO COL / SUPPORTING BEAM U.N.
- BINDING WIRES SHALL BE 16 GUAGE 1.6mm SOFT ANNEALED STEEL WIRES FREE FROM RUST AND OTHER CONTAMINANTS.
- CONCRETE DESIGN MIX REPORT.
- CONCRETE DESIGN MIX REPORT ALONG WITH THE TEST RESULTS FOR CONCRETE CUBES SHALL BE SUBMITTED IN ADVANCE FOR APPROVAL BEFORE RELEVANT CONCRETING. AND THE MINIMUM CEMENT CONTENT SHALL BE NOT LESS THAN 300 Kg/m
- SLUMP SHALL BE 100 + 25mm.
- POURING OF CONCRETE.
NO CONCRETING OPERATION SHALL BE CARRIED OUT DURING INCLEMENT WEATHER CONDITIONS LIKE HEAVY RAIN, STORM AND HIGH WINDS.
