Advantages of ready mix concrete for the supply of assured quality of concrete and services offered are known. Now the time has come to design and produce concrete mixes for delivery to project within three to four hours after the cement and water are mixed. Super plasticisers should be added and the temperature of the concrete maintained at 32 deg to 33 deg C when placed into forms. Advanced research in admixture technology has shown that the initial and final set of concrete can be extended two to three hours from initial set of cement when different dosages of admixture are used at different temperatures. The technology assures that there is no loss in the properties of the concrete. Specification for ready mix concrete should now incorporate mixing time requirement beyond 1 to 1-1/2 hours due to traffic jam and equipment problems.
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