Admixtures. The superplasticizer admixture must be a high-range water reducer (HRWR) capable of increasing the slump of the mix from approximately 2½ inches to 6½ inches upon the addition of the amount recommended by the respective manufacturer. The HRWR must conform to ASTM C494 Type F or Type G and shall be approved by the ConnDOT engineer when ConnDOT is the Client Agency. The use of this material must be in strict accordance with the respective manufacturer's written instructions and procedures.
Admixtures. Usually the water proof concrete specifications are written aiming to achieve a watertight concrete structures. But practically the concrete can sometime be very difficult to place. If agreed by the Engineer, the contractor will be permitted to use concrete with more plastic consistency helping to produce a smoother and denser floor and wall finishes requirements. In heavy reinforced structures, a good and long workability is also important. It is impossible to meet the water/cement ration > 0.5 and a good workability requirements at the same time unless concrete admixtures are used. Contractor may use admixtures and shall use if required by the Engineer admixtures such as: − Retarder − Accelerator − Plasticizer or super plasticizer − air entraining agent − water proofing admixtures − Fluid admixtures − Anti freeze admixtures Plasticizer and super plasticizer gives good workability and correct consistency (even for pumped concrete with extended working times) to enable the concrete to be compacted as fully as possible in as short a time as possible with a high reduction in the water/cement ratio.
Admixtures. A. No admixtures will be permitted without prior notification and approval of the Design Professional and/or Inspector.
Admixtures. (a) Air-entraining admixtures shall conform to the requirements of ASTM C260.
Admixtures a. Include limitations of use, including restrictions on cementitious materials, supplementary cementitious materials, air entrainment, aggregates, temperature at time of concrete placement, relative humidity at time of concrete placement, curing conditions, and use of other admixtures.
Admixtures. A. Use water-reducing admixture or high-range water – reducing admixture (Super- plasticizer) in concrete as required for placement and workability.
Admixtures. Admixtures may be used in concrete, only with the approval of the Engineer-in-Charge based upon evidence that, with the passage of time, neither the compressive strength of concrete is reduced by more than 10 percent nor are other requisite qualities of concrete and steel impaired by the use of such admixtures. Calcium chloride should not be used. Admixtures, if used shall comply with IS: 9103.
Admixtures. In order to reduce the cement content and/or the amount of missing water, and to improve the concrete workability, the Contractor may be allowed to use Admixtures and as such he shall submit to Engineer-in-Charge for approval of such Admixture he proposes to use. However, no additional payment will be made by the Engineer-in- Charge to the Contractor in view of this as the cost thereof is considered included in the contract unit price for the different classes of concrete.
Admixtures. A. Air Entrainment Admixture: ASTM C260.
Admixtures. Use of superplasticizers in concrete shall be permitted. Admixture shall comply with IS 6925 .the cost of admixtures shall be borned by the Contractor.
