2. Means and Methods Flashcards
What factors determine the maximum internal load that a wall formwork can resist?
(1) Placement rate of concrete and (2) temperature of concrete.
What is the weight for light, normal, and heavy concrete, respectively?
Light < 140 pcf, Normal = 140-150 pcf, Heavy > 150 pcf
What factors affect lateral pressure in formwork?
Weight of Concrete, Concrete Chemistry, Temperature, Rate of Placement, Concrete Slump, and Vibration.
What is the primary method of consolidating concrete?
Internal vibration
When should liquid head pressure be used for formwork lateral pressure?
Slump > 7 in OR Vibration depth > 4 ft OR Rate of Placement > 15 ft/hr
How much load should scaffolding be able to support?
Its own weight plus at least 4x the max intended load.
What is the max deflection of a scaffolding platform?
No more than 1/60 of the span length when loaded
What are the minimum concentrated loads for personnel and equipment?
250 lbs per person; 500 lbs per wheel of manually powered vehicle; 2000 lbs per wheel of powered equipment.
What loads are included in construction loads?
Material, Personnel, and equipment.
What are the two categories of material dead loads?
Fixed and Variable
How are personnel and equipment loads analyzed?
By uniformly distributed loading or concentrated loading; which ever creates the most severe strength and serviceability conditions.
What construction loads are allowed to be reduced?
Personnel and Equipment loads (material loads, fixed or variable are not allowed to be reduced).
Which load combinations are used for construction loads?
Strength Design (Load and Resistance Factor Design for temporary structures) and Allowable Strength Design.
Which loads are not to be considered simultaneously?
Wind and Earthquake load and Horizontal Construction load
What is the minimum lateral pressure that must be used for formwork?
600 x Unit Weight Coefficient Cw
