Of 25 nmm2 at 28 days if mortar is or is 8112 1976e

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Unformatted text preview: cement content of 600 kg/m3 and a compressive strength not less than use of pozzolana as an admixture to NOTE -The Portland cement is not permitted. Unless otherwise 25 N/mm2 at 28 days. 4.1 For precast concrete pipes, materials complying specified by the purchaser, used is left to the discretion the type of cement of the manufacturer. to be Where the process of manufacture is such that the strength of concrete or mortar in the pipe differs from that given by tests on cubes, the two may be related by a suitable conversion factor. If the purchaser requires evidence of this factor, he shall ask for it before placing the order. The conversion factor for 28 days compressive strength for spun concrete may be taken as 1’25 in the absence of any data. 4.3 Aggregates - Aggregates used for the manufacture of unreinforced and reinforced concrete pipes shall conform to IS : 383-19707. The maximum size of aggregate should not exceed one third the thickness of the pipe or 20 mm, whichever is smaller. 4.4 Reinforcement - Reinforcement used for the manufacture of the reinforced concrete pipes shall be mild steel Grade 1 or medium tensile steel bars conforming to IS : 432 ( Fart 1 )-1982* or harddrawn steel wire conforming to IS : 432 ( Part 2 )19829 or structural steel ( standard quality ) bars conforming to IS : 226-1975lO. Where soft grade wire is used, it shall conform to IS : 280-1978’l. 4.5.2 For pressure pipes splitting .tensile strength of concrete cylinders at 28 days, when tested in accordance with IS : 5816-9701, shall be 2’5 N/mm2. 4.5.3 Compressive strength tests shall be conducted on I5 cm cubes in accordance with the relevant requirements of IS : 456-1978’ and IS : 516-1959’. to IS : 1566-1982l’ NOTE- Wire fabric conforming or deformed bars and wires conforming to 1s : 178619851*may also be used. 4.5.4 The manufacturer shall give a certificate indicating the quantity of cement in the concrete mix. 4.5 Concrete or Mortar - Concrete used for the manufacture of unreinforced and reinforced concrete pipes and collars shall conform to 1s : 456-197814. 4.6 Rubber Ring - Rubber ring chords used in pipe joints shall conform to Type 1A of IS : 5382-I967*. ‘Specification for ordinary ,and low heat Portland cement ( third revision ). %pecification for Portland slag cement (third revision). aspecification for Portland pozzolana I cement ( second revision ). *Specification for rapid hardening Portland cement (first revision ). 5Specification for hydrophobic Portland cement (first revision ). %pecification for 43 grade ordinary Portland cement (first revision ). 7Specification for coarse and fine aggregates from natural sources for concrete ( second revision ). 5. DESIGN Reinforced concrete pipes either spun or cast shall be designed such that the maximum tensile stress in the circumferential steel due to specified hydrostatic test pressure does not exceed the limit of I25 N/mm2 in the case of mild steel rods, 140 N/mm2 in the case of hard-drawn st...
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This document was uploaded on 10/01/2013.

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