South Carolina Concrete

Quality control directly controls the product to meet requirements, while quality assurance verifies that those controls are in place and working.

Retarding admixtures delay concrete setting and increase lateral pressure on forms (chemistry coefficient CC = 1.2), requiring longer form stripping times, whereas normal cement uses CC = 1.0 with standard stripping schedules.

Form ties use a 2:1 safety factor (working load = half the ultimate tensile strength), while form anchors require a minimum safety factor of 3 because they are often loaded while the concrete is still green.

Bending stress calculations for plywood sheathing must use effective section modulus (KS), while deflection calculations use moment of inertia (I), because the effective moment of inertia divided by distance to extreme fiber does not equal KS for plywood.

Pier shaft forms may be stripped after just 1 day, while supported cap beam forms must remain in place for a minimum of 14 days, necessitating two complete cap beam form sets to maintain schedule.

Architectural formwork sheathing, studs, and wales should be limited to l/400 deflection to prevent surface blemishes, which is more restrictive than the typical l/360 limit used for standard formwork.

Shielded or lead-covered conductors rated over 1000 V must have a minimum bending radius of 12 times the overall diameter, while nonshielded conductors require only 8 times the overall diameter.

Type MV-90 medium voltage cable has a maximum operating temperature of 90°C, while Type MV-105 is rated for a maximum of 105°C; both are suitable for dry or wet locations.

For continuous spans, the interior shore carries 1.25wℓ rather than the wℓ calculated by simple tributary area, so non-manufactured shores must have their tributary-area load increased by 25% to account for continuity effects.

Concrete exposed to freezing-and-thawing with deicing chemicals (F3) requires a maximum w/cm of 0.40, which is more restrictive than the 0.50 maximum required for concrete in contact with water where low permeability is required (W1).

Wood joists or structural floor bottoms in a crawl space require decay protection when closer than 18 inches to exposed ground, while wood framing columns resting on exterior concrete or masonry foundation walls require protection when less than 8 inches from exposed ground.

Criterion A requires the average of any three successive tests to equal or exceed the specified strength fc′, while Criterion B requires that no single test fall more than 500 psi below fc′ (for fc′ ≤ 5000 psi) or more than 10% below fc′ (for fc′ > 5000 psi).