||Strength increasing admixtures increase concrete strength more rapidly than concrete without the admixtures. They also extend the concrete setting time. Accelerating admixtures can be added to the concrete to reduce the setting time. Retarding admixtures slow the concrete setting rate to help place and finish the concrete when high temperatures speed up hardening. They also delay the setting of concrete when placing concrete in large and difficult piers and foundations. Early concrete strength can be increased by accelerating admixtures such as Calcium Chloride. It is added to the concrete as part of the water mixing solution to make sure all of it gets dissolved. Calcium Chloride can cause scaling, reinforcement corrosion, drying shrinkage, and darken the concrete. It should never be used as a concrete antifreeze because it only reduces the freezing point of concrete by only a few degrees.|
Materials In Concrete.
2.Concrete Aggregates - Concrete Slump.
3.Concrete Placement - Vibration - Hydration.
4.Types of Portland Cement - Concrete Moisture & Cracking.
5.Watertight Concrete - Supplementary Cementing Materials.
6.Supplementary Cementing Materials.
7.Chemicals That Damage Concrete.
8.Concrete Aggregate Properties.
9.Angular & Smooth Aggregate Properties.
12.Air Entraining Admixtures.
13.Air Entraining Admixtures Continued.
14.Conditions Affecting Concrete Air Volume.
15.Superplasticizers & Other Admixtures.
16.Ordering & Mixing Concrete.
17.Concrete Mixing - Subgrade Preparation.
18.Subbase Preparation - Concrete Placement.
22.Hot Weather Concreting.
23.Cold Weather Concreting.
24.Concrete Slump Test.