WRDA® 82

Uses

WRDA® 82 makes a workable mix and yields a stronger, less permeable and more durable concrete. It is used in ready-mix plants, job site plants and concrete pavers, for normal weight and light weight concrete, in block, precast and prestressed concrete plants.

Performance

WRDA 82 is a chemical admixture meeting the requirements of Specification for Chemical Admixtures for Concrete, ASTM Designation: C494 as a Type A and D admixture.

As a dispersing agent, WRDA 82 lessens the natural interparticle attraction between cement grains in water. It does this by colloidal action, by adsorption on the cement particles thus reducing their tendency to clump together and makes the mix more workable with less water. As a cement catalyst, WRDA 82 effects a more complete hydration of the cement, beginning immediately after the cement and water come together at the lower additions of WRDA 82 or immediately after a period of designed and controlled hydration at the higher additions. WRDA 82 increases the gel content of the concrete, the paste or binder that “glues” the concrete aggregates together. The increased gel content adds to the water retention and internal cohesiveness of the mix, reducing bleeding and segregation as it increases workability and placeability

Product Advantages

• Superior water reduction and set times
• Consistent set time
• Improves performance concrete containing supplementary cementitious materials
• Produces concrete that is more workable, easy to place and finish
• High compressive and flexural strengths

Addition Rates

The addition rate range of 3 to 5 fl oz/100 lbs (195 to 326 mL/ 100 kg) of cement or cementitious is typical for most applications. However, addition rates of 2 to 10 fl oz/100 lbs (130 to 652 mL/ 100 kg) of cement or cementitious may be used if local testing shows acceptable performance. In some cases it may be necessary to slightly modify the addition rate due to variations in cement, aggregate or other job conditions.

Compatibility with Other Admixtures and Batch Sequencing

WRDA 82 is compatible with most GCP admixtures as long as they are added separately to the concrete mix, usually through the water holding tank discharge line. In general, it is recommended that WRDA 82 be added to the concrete mix near the end of the batch sequence for optimum performance. Different sequencing may be used if local testing shows better performance. Please see GCP Technical Bulletin TB-0110, Admixture Dispenser Discharge Line Location and Sequencing for Concrete Batching Operations for further recommendations.