MIX DESIGN. 45.1 The following instructions shall be followed as regards preliminary design of mix and methods of batching of plain cement concrete and reinforced cement concrete. These instructions should be treated as supplementary to the relevant provision in the specifications for the respective items contained in the book of standard specifications and will override the provisions contained therein wherever they are contrary to the following instructions. Sr No Concrete Grade Guidelines
1) Upto M-15: This should only be ordinary concrete. No change may be prescribed in the present practice as regards preliminary design of mix and permitting volume batching. Only cement to weight batched
2) M-20 and above Preliminary mix design must be prepared for such mixes Weight batching shall be insisted for cement fine aggregate and course aggregate.
45.2 For the grades of concrete M-20 and above the preliminary mix design shall be carried out from the approved laboratory.
(1) The charges for preliminary design, of concrete mix shall be entirely borne by the contractor.
(2) For grades of concrete M-20 and above where cement is to be used by weight, the cost of extra cement required to make-up the under-weight bags shall be borne by the contractor.
(3) For the items of concrete of grades lower than M-20 and other items in the agreement, where cement is not to be used by weighment, the cement bags as received from the manufacturer and supplied to the contractor under Schedule ‘A’ shall contain cement of 50 Kg. net weight.
45.3 The admixtures such as plasticizers/super plasticizers for concrete grade M-20 and above shall be used as directed by Engineer in charge depending upon specific requirements. No extra payment s on this account will be admissible ADDITIONAL TENDER CONDITIONS
MIX DESIGN. The following instructions shall be followed as regards preliminary design of mix and methods of batching of plain cement concrete and reinforced cement concrete. These instructions should be treated as supplementary to the relevant provision in the specifications for the respective items contained in the book of standard specifications and will override the provisions contained therein wherever they are contrary to the following instructions. The preliminary mix design and batching for various grades of concrete shall be governed by the following guidelines.
MIX DESIGN. 45.1 The following instructions shall be followed as regards preliminary design of mix and methods of batching of plain cement concrete and reinforced cement concrete. These instructions should be treated as supplementary to the relevant provision in the specifications for the respective items contained in the book of standard specifications and will override the provisions contained therein wherever they are contrary to the following instructions. The preliminary mix design and batching for various grades of concrete shall be governed by the following guidelines. Concrete Grade Guidelines
1) Upto M-15: This should only be ordinary concrete. No change may be prescribed in the present practice as regards preliminary design of mix and permitting volume batching. Only cement to weight batched 2) M-20 to M-25 : Preliminary mix design must be carried out for these mixes. However, weight batching shall be insisted for cement .only for concrete m-20 and above
MIX DESIGN. Immediately upon the receipt of the award of the contract, the Contractor shall inform the Engineer-in- charge the exact location of the sources of materials which he proposes to use and get the materials approved. The mix with the actual approved materials to be used shall be got designed by the Contractor in an approved laboratory chosen by BHEL and got approved by the Engineer-in-charge. These proportions shall be used so long as the materials continue to be the same quality and from the same sources. If during the progress of work, the Contractor wishes to change the materials, the proportions shall be fixed on the basis of fresh preliminary tests to give the required strength. No change of materials shall be allowed unless fresh tests with new materials show satisfactory results.
MIX DESIGN. The Contractor shall supply the mix design data for the RAP mixes (including asphalt content of the RAP) to the Project Engineer.
MIX DESIGN. THE FIRST PARAGRAPH IS CHANGED TO: Design the SMA to meet the requirements in Table 902.05.02-1 and Table 902.05.02-2. Prepare the JMF according to AASHTO R 46. Determine the JMF at 4 percent air voids and 75 gyrations of the Superpave gyratory compactor. TABLE 902.05.02-2 IS CHANGED TO: Air Voids ±1% 4.0% Voids in Mineral Aggregate (VMA) – 17.0% minimum VCAmix – Less than VCAdry Draindown @ production temperature – 0.30% maximum Asphalt Binder Content (NJDOT B-5) ±0.15% 6% minimum Asphalt Binder Content (AASHTO T 308) ±0.40% 6% minimum Tensile Strength Ratio (AASHTO T 283) – 80% minimum
MIX DESIGN. 1.2.3.1 to minimize variations in colour and shading and ensure a high degree of visual conformity, only one concrete mix will be permitted for areas subject to blasting;
1.2.3.2 sufficient quantities of all ingredients required to complete the Work using the same design mix must be available; and
1.2.3.3 once the design mix has been reviewed by the Designer, it shall not be varied as to source, quantity, quality, grading of materials, or proportioning, or any other aspect of the materials affecting the design.
MIX DESIGN. 44.1) The following instructions shall be followed as regards preliminary design of mix methods of batching of plain cement concrete and reinforced cement concrete. These instructions should be treated as supplementary to the relevant provision in the specifications for the respective items contained in the book of standard specifications and will override the provisions contained therein wherever they are contrary to the following instructions. The preliminary mix design and batching for various grades of concrete shall be governed by the following guidelines. Concrete Grade Guidelines
1 Up to M-15 This should only by ordinary concrete. No change may be prescribed for the present practice as regards preliminary design of mix permitting volume batching.
2 Contrac M-20 tor Preliminary mix design must be carried out for these mixes. However, weight batching shall be insisted for cement only. No of correction University Eng
MIX DESIGN. A. All concrete shall consist of proper proportions of Portland Cement, coarse aggregates, fine aggregates and clean water conforming to application of A.S.T.
MIX DESIGN. A. All concrete shall consist of proper proportions of Portland Cement, coarse aggregates, fine aggregates, and clean water conforming to application of A.S.T.M. Standard Specifications.
B. Concrete for footings, foundations, and dock leveler pits shall be a minimum of 3,000 p.s.i. strength at twenty-eight (28) days.
C. Concrete for interior flatwork shall be a minimum of 4,000 p.s.i. strength at twenty-eight (28) days.
D. Concrete for tilt wall panels shall be a minimum of 4,000 p.s.i. strength, or as recommended by the structural engineer, at twenty-eight (28) days.
E. Concrete for exterior paving shall be a minimum of 3,000 p.s.i. strength at twenty-eight (28) days.
F. The allowable time limit for batching of the concrete trucks shall be ninety (90) minutes.
G. A copy of the mix designs shall be provided to Owner and the testing laboratory.
