The primary difference between these admixtures and conventional water-reducing admixtures is that high range water reducing (HRWR) admixtures, often referred to as superplasticizers, may reduce the water requirement by more than 30%, without the side effect of excessive retardation.

Potential Advantages of HRWR:

1. Significant water reduction;

2. Reduced cement contents;

3. Increased workability;

4. Reduced effort required for placement;

5. More effective use of cement;

6. More rapid rate of early strength development;

7. Increased long-term strength; and

8. Reduced permeability.

Potential Disadvantages of HRWR:

1. Additional admixture cost (the concrete in-place cost may be reduced);

2. Slump loss greater than conventional concrete;

3. Modification of air-entraining admixture dosage;

4. Less responsive with some cement;

5. Mild discoloration of light-colored concrete; and

6. Air-void and color blemishes on exposed and formed finishes.

(Reference: NRMCA Publication No. 158)