||Concrete should not be placed any faster than it can be spread, struck off, consolidated, and bull floated or darbied. Spreading concrete over too large an area can can allow too much bleed water to accumulate before bull floating. Screeding must be completed before too much bleed water accumulates. The concrete can be finished by strikeoff or screeding to bring the top surface of the slab to proper grade, and bull floating to level the high and low spots and submerge large aggregates. Other finishing techniques can be applied if they are required such as brooming for slip resistance, edging for compaction, jointing for control joints, floating for leveling, troweling for a smooth hard surface, and adding patterns and textures for aesthetics. Newly placed concrete should be cured and protected from rapid drying, extreme temperature changes, and damage from traffic. In winter, concrete can be heated, covered, insulated and enclosed. In summer, concrete can be cured by covering it with wet burlap to protect it from drying out too quickly.|
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.