||Fly ash and ground slag reduce the heat build up in concrete because their heat of hydration is lower than Portland cement. Ground granulated blast furnace slag, fly ash and natural pozzolans slow the setting time in concrete. Concrete with Portland cement and supplementary cementing materials can take longer to cure and gain strength than concrete with Portland cement alone. Supplementary cementing materials improve concrete finishability. Silica fume is good at increasing concrete pumpability. Silica fume may colour concrete blue or dark grey, and fly ash may give it a tan colour. Ground granulated blast furnace slag and fly ash help increase the strength of concrete and reduce permeability. Silica fume also reduces permeability. Slag, fly ash and silica fume improve concrete resistance to sulphate corrosion. Fly ash and silica fume provide corrosion protection to steel embedded in concrete.|
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.