Unit Rate (Rate Contract) For The Items Of Works For Various Works In Narmada District; 1.1 WATER(M-1):- 1.1.1 Water for mixing cement mortar or concrete shall not be salty or blackish andshall be clean, reasonable clear and free from objectionable quantities of silt and trances ofsoil,acidand injuriousalkali,salts,organicmatter andotherdeleterious materials which will either weaken the mortar or concrete or cause efflorescence or attack the steel in R.C.C. Water shall be obtained from sources approved bythe Engineer- In-Charge. Sources of water shall be obtained from sources approved by the Engineer-In-Charge. Sources of water shall be maintained at such a depth and the water shall be withdrawn in such a manner as to exclude silt, mud, grass or other foreign materials. Containers for transport, storage and handling of water shall be clean. Water shall conform to the standard specification in I.S. 456. 1.1.2 Itshallbetestedbycomparisonwithdistilledwater.Comparisonshallbemadeby means of standard cement tests for soundness, time of setting and mortar strength as specified in I.S. 269. Any indication of unsoundness, change in time of setting by 30 minutes or more, or decrease of more than 10 percent in strength of mortar prepared with the water sample when compared with the results obtained with mortar prepared with distilled water shall be sufficient cause for rejection of water tested. Sea water shall not be used; 1.1.3 Samples of water shall be collected and sent for testing to Government laboratory for each source of water periodically even if source remain unchanged, at contractor’s cost. The frequency shall be decided by Engineer-In-Charge. Waterfit for drinking will generally be found suitable for mixing cement mortar or concrete. 1.1.4 WaterforConstructionwork &curing:- Water for curing mortar or concrete should not be too acidic or too alkaline. It should have a PH value ranging from 6.00 to 8.00. PH value of water shall not be less than 6.00 To neutralize 100ml of sample water using phenolphthalein as indicator should not require more than 5ml of 0.02N–NaOH Ref IS–3025 (Part 22). To neutralize 100ml of sample water should not require more than 25ml of 0.02NH2SO4(IS–3025Part23).Average28daysstrengthwith desiredwatershall not be below 90% strength of concrete prepared with distilled water. It shall be free of elements which significantly effect the hydration reaction or otherwise interferencewiththehardeningofmortarorconcreteduringcuringorthosewhich produce objectionable stains or other unsightly deposits on concrete or mortar surfaces. PermissibleLimitsofSolidsshallnotexceedthefollowing. SR. No. Testedasper PermissibleLimit,Max, (i) Organic IS3025(Part18) 200mg/l (ii) Inorganic IS3025(Part18) 3000mg/l (iii) Sulphates (as SO3) IS3025(Part24) 400mg/l (iv) Chlorides (as Cl) IS3025(Part32) 2000mg/l forconcretenot contain embeddedsteeland500mg/lfor reinforcement concrete work (v) Suspended matter IS3025(Part17) 2000mg/l Sea water and water containing over 3 percent of chloride salts should not be used for curing reinforced concrete work. Potable water will generally be found suitable for curing cement mortar or concrete. M-2 CEMENT :- 2.1 Cement shall be ordinary Portland cement as per I.S. 269-1976 or Portland cement as per I.S. 455-1976. M-3 SAND:- 3.1 Sand shall be natural sand, clean well graded, hard, strong, durable and gritty particles free from injurious amount of dust clay, kankar, nodules, soft or flaky particles, shale, alkali, salts, organic matter, loam, mice or other deleterious substances and shall be got approved by the Engineer-in- Charge. The sand shall not contain more than 5 percent of silt as determined by field test if necessary. The sand shall be washed to make it clean. 3.2 COARSE SAND The fineness modules of coarse sand shall not be less than 2.20 and shall not exceed 3.00 The sieve analysis of coarse sand shall be as under :- I.S. SIEVE PERCENTAGE I.S. SIEVE PERCENTAGE DESIGNATION BY WEIGHT DESIGNATION BY WEIGHT PASSING SIEVE PASSING SIEVE 4.75 mm 100 600 micron 30 to 100 2.36 mm 90 to 100 300 micron 5 to 70 1.18 mm 70 to 100 150 micron 0 to 50 M-4 GRAVEL :- 4.1 Gravel shall be clean, hard, dense, tough and durable and free from alkalis and other organic matter and other deleterious substances and shall be screened and washed as directed. The gravel shall be round & flaky. Elongated and weathered pieces shall be avoided. 4.2 SIZE OF GRAVEL Unless otherwise specified by the Engineer-in-Charge the maximum size of aggregate for different types of concrete shall not exceed the limits given below :- CLASS OF WORK NOMINAL SIZE OF AGGREGATE 1. R.C.C. Work 20 mm 2. Ordinary plain concrete 40 mm 3. Foundation concrete 40 mm 4. Mass concrete 80 mm 4.3 GRANDING OF GRAVEL The gravel shall be well graded. The grading of the above sizes shall be within the limits as given in table below. TABLE : 1 I. S. SIEVE PERCENTAGE OF PASSING FOR GRADED GRAVEL OF NOMINAL SIZE 80 mm 40 mm 20mm 80mm 90 to 100 100 --- 63mm 65-80 -- --- 40mm 55-65 95-100 100 20mm 10-30 30-70 95-100 16mm -- -- -- 12.5mm -- -- -- 10mm 0-5 10-35 25-55 4.75mm -- 0-5 0-10 3.26mm 0-5 -- --- M-5 BRICKS :- 5.1 Bricks shall be hand or machine moulded and made from suitable soil and kiln burnt. Bricks shall be free from cracks and flaws and nodules of free lime. They have smooth rectangular faces with sharp corners and shall be of uniform color. Bricks shall be moulded from 100 mm x 40 mm x 10 mm to 20 mm deep on one of its flat sides. The bricks shall not break when thrown on the ground from a height of 60 cm. The size of brick shall be 22 cm. x 11 cm. x 6cm. Only bricks of one standard size shall be used. 5.2 The crushing strength of bricks shall not be less than 35 kg/ cm2. The average water absorption shall not be more than 20% by weight. M-6 M.S. BARS :- 6.1 High yield strength steel deformed bar shall be either cold twisted or hot rolled and shall confirm to I. S. 1739-1966 or their latest version respectively. 6.2 All the bars shall be clean and free from dirt, paint, grease, mill scale or loose or thick rust at the time of placing. M-7 NP-2 CLASS HUME / R.C.C. PIPES :- (1) The pipe shall confirm to I.S. 458 of 1988 or its latest version so far they apply to NP2 class pipes in all respects, such as materials, design, manufacturing, dimensions, workmanship and finish, tests, sampling and inspection etc. (2) The surface and edges of the pipes shall be well defined and true and their ends shall be square with longitudinal axis. (3) The internal diameter, wall thickness, length and thickness of collar of pipes, the minimum reinforcement and strength test requirement shall be as specified in I. S. 458-1988. (4) Pipes shall be straight and free from cracks. The ends of pipes shall be square with their longitudinal axis so that when places in a straight line in trench, no opening between ends in contact shall exceed 3 mm in pipes up to 600 mm diameter (inclusive) and 6 mm in pipes larger than 600 mm diameter 5) The outside and inside surface of the pipes shall be smooth, dense and hard, and shall not be coated with cement wash or other preparation unless otherwise directed by Engineer-in-Charge for better bond, inner surface of collar may be finished rough. (6) The pipes shall be free from defects resulting from imperfect grading of the aggregate mixing or moulding. (7) Pipes shall confirm requirement as per relevant Indian Standards code as practice when subject to the hydrostatic test, three-edge bearing lest, absorption test, dimension test etc. M-8 STONE (RUBBLE) :- (1) The stone shall be of the specified variety such as granite/trap/quaizite or any other type of good hard stones. The stone shall be obtained only from the approved quarry and shall be hard sound, durable and free from defects like cavities, cracks, sand holes, flaws, injurious viens, patches of loose or soft materials etc. and weathered portions and other structural defects or imperfections tending to effect their soundness and strength. The stones with round surface shall not be used. The percentage of water absorption shall not be more than 5% of dry weight when tested in accordance with I. S. 1134-1974. The minimum crushing strength of the stone shall be 200 kg/cm2 unless otherwise specified. M-9 METAL :- (1) Metal shall be of machine crushed stones of black trap or equivalent and be hard, strong, durable, clean and free from sking & coating likely to prevent proper adhesion of mortar. Metal shall generally be cubical in shapes. Unless special stone of particular quarries are mentioned, metal shall be machine crushed from best black trap or equivalent hard stone as approved. Metal shall have no deleterious reaction with cement. (2) Size of metal :- Unless otherwise specified by the Engineer-in-Charge the maximum size of metal for different type at concrete shall not exceed the limits given below However in case of reinforced cement concrete the maximum limits shall be restricted to 6 mm less then the minimum lateral clear distance between bars or 6 mm less then the cover in smaller. Class of work Nominal size of metal 1. R.C.C. Work 20 mm 2. Ordinary plain concrete 40 mm 3. Foundation concrete 40 mm 4. Mass concrete 80 mm
