- 1 What determines when formwork can be removed from cast in place concrete?
- 2 Can support for precast concrete be removed when permanent connections are completed?
- 3 Who must determine when forms and shores?
- 4 What must be established prior to masonry wall construction?
- 5 Can you leave concrete forms on too long?
- 6 How soon can you strip concrete forms?
- 7 How many employees should be in the building or structure during a jacking operation?
- 8 Who is responsible for safe site layout?
- 9 What are struck by guidelines?
- 10 Who will design concrete shoring and reshoring systems?
- 11 When can Shoring be removed?
- 12 How do you strengthen concrete?
- 13 What reinforcing steel is guarded with caps to protect from impalement?
- 14 What is a controlling contractor?
- 15 What kind of block is used around the top of a block structure?
What determines when formwork can be removed from cast in place concrete?
Reshoring shall be erected, as the original forms and shores are removed, whenever the concrete is required to support loads in excess of its capacity.
Can support for precast concrete be removed when permanent connections are completed?
Precast concrete wall units, structural framing, and tilt-up wall panels shall be adequately supported to prevent overturning and to prevent collapse until permanent connections are completed.
Who must determine when forms and shores?
According to OSHA, jacking equipment being used to raise a 2-ton steel column must be capable of supporting at least 5 tons. Who must determine when forms and shores may be removed? The employer must determine when forms and shores may be removed.
What must be established prior to masonry wall construction?
The limited access zone shall be established prior to the start of construction of the wall. All masonry walls over eight feet in height shall be adequately braced to prevent overturning and to prevent collapse unless the wall is adequately supported so that it will not overturn or collapse.
Can you leave concrete forms on too long?
The forms or “molding” that holds the concrete in place until it dries should be left alone for at least two days to ensure that the concrete is completely dry. If the forms are removed too soon, the concrete can begin to sag, crack and collapse, especially if conditions like temperature affected its strength.
How soon can you strip concrete forms?
A. The forms should remain in place for at least 8 to 12 hours after the wall is poured, if the temperature is above 50° F. You can begin laying your sills and joists, and building light frame walls, immediately thereafter.
How many employees should be in the building or structure during a jacking operation?
No employee, except those essential to the jacking operation, shall be permitted in the building/structure while any jacking operation is taking place unless the building/structure has been reinforced sufficiently to ensure its integrity during erection.
Who is responsible for safe site layout?
The controlling contractor must ensure that the following is provided and maintained [29 CFR 1926.752(c)]: Adequate access roads into and through the site for the safe delivery and movement of: Derricks. Cranes.
What are struck by guidelines?
According to OSHA, “Struck” is defined as: injuries produced by forcible contact or impact between the injured person and an object or piece of equipment. Struck-by hazards in construction cause accidents such as the following: A construction worker was hoisting bricks in a bucket to the top of a building.
Who will design concrete shoring and reshoring systems?
The form removal and shoring plan is the contractor’s responsibility, but since according to ACI 301 it should be submitted to the structural engineer to review, some responsibility transfers to the design professional. In the end, though, OSHA puts the responsibility on the concrete contractor.
When can Shoring be removed?
In no case shall the supporting forms or shoring be removed until the members have acquired sufficient strength to support safely their weight and the load thereon.
How do you strengthen concrete?
Reinforce a concrete pour with rebar or steel mesh. Rebar is the most common addition for strengthening the pour. In vertical or horizontal projects, the more rebar present in the concrete, the stronger the finished project will be.
What reinforcing steel is guarded with caps to protect from impalement?
Steel reinforced rebar caps provide the strongest and best impalement protection for workers. Proper protective rebar caps should be at least 4” square or, if they are round, they should have a 4.5 inch diameter.
What is a controlling contractor?
“a prime contractor, general contractor, construction manager or any other legal entity, which has the overall responsibility for the construction of the project – its planning, quality and completion.” Subpart R contains several specific duties that have been placed on the controlling contractor.
What kind of block is used around the top of a block structure?
Lintel blocks, also known as channeled blocks, are U-shaped concrete masonry units. They are primarily used in the preparation of lintel beams. Attached on top of windows and doors, these blocks bear the load coming from the top.