Common use of Gradation Clause in Contracts

Gradation. (i) Unless otherwise directed or approved by the Engineer, the grading of sand shall be within the limits indicated hereunder : IS Sieve Designation Percentage passing for 10mm 100 100 100 100 4.75mm 90 – 100 90 – 100 90 – 100 95 – 100 2.36 60 – 95 75 – 100 85 – 100 95 – 100 1.18mm 30 – 70 55 – 90 75 – 100 90 – 100 600 micron 15 – 34 35 – 59 60 – 79 80 – 100 300 micron 5 – 20 8 – 30 12 – 40 15 – 50 (ii) Where the grading falls outside the limits of any particular grading zone of sieves, other than 600 micron I.S sieve, by total amount not exceeding 5 percent, it shall be regarded as falling within that grading zone. This tolerance, shall not be applied to percentage passing the 600 micron I.S. sieve or to percentage passing any other sieve size on the coarser limit of Grading Zone I or the finer limit of Grading Zone IV. Fine aggregates conforming to Grading Zone IV shall not be used. Mix designs and preliminary tests shall show its suitability for producing concrete of specified strength and workability.

Gradation. (iI) Unless otherwise directed or approved by the Engineer, the grading of sand shall be within the limits indicated hereunder under here: IS Sieve Designation Percentage passing for 1010 mm 100 100 100 100 4.754.75 mm 90 – 100 90 – 100 90 – 100 95 – 100 2.36 mm 60 – 95 75 – 100 85 – 100 95 – 100 1.181.18 mm 30 – 70 55 – 90 75 – 100 90 – 100 600 micron 15 – 34 35 – 59 60 – 79 80 – 100 300 micron 5 – 20 8 – 30 12 – 40 15 – 50 (iiII) Where the grading falls outside the limits of any particular grading zone of sieves, other than 600 micron I.S I.S. sieve, by total amount not exceeding 5 percent, it shall be regarded as falling within that grading zone. This tolerance, tolerance shall not be applied to percentage passing the 600 micron I.S. sieve or to percentage passing any other sieve size on the coarser limit of Grading Zone I or the finer limit of Grading Zone IVAVE. Fine aggregates conforming to Grading Zone IV AVE shall not be used. Mix designs and preliminary tests shall show its suitability for producing concrete of specified strength and workability.