What concrete is used for blinding?
GRADE: C15 CONCRETE An ideal concrete mix for floor blinding and kerb mix.
Is concrete blinding necessary?
Blinding concrete should only be used: to protect the bottom of the trench/excavation where there is a delay in pouring structural concrete. where the foundation has been slightly overdug. to provide sufficient support to ensure cover to reinforcement is maintained, or.
What is floor blinding?
Blinding is the process of pouring a thin layer of concrete over the floor of a new building; this can be over the hardcore or over the foundation itself. The purpose of this is to seal in underlying material and prevent dirt and mud from interfering with the structure.
What is the allowable thickness of concrete in foundation?
Minimum Thickness of Concrete Footing
|Type of Footing||Minimum Thickness|
|Masonry||250 mm; twice the maximum projection from the face of the wall|
|Plain concrete||200 mm, or twice the maximum offset in a stepped footing|
|Reinforced concrete (depth above bottom reinforcement)||150mm 300mm|
Can you use building sand for blinding?
2 Answers from MyBuilder Groundworkers Building sand is finer so a very thin scattering of that would be fine. I put what I thought was a thin blinding on at one job and the planning regs folks told me to take 3/4 off, so it really is a very thin scattering.
What sand is used for blinding?
Sharp sand is fine for blinding provided you use a lot of it and rub it in to the eyeballs really hard.
Can I use building sand for blinding?
How do you mix concrete blinding?
- Concrete blinding is just 2″ of regular concrete mix.
- People try to use finer aggregates for this purpose because of the thickness required.
- Depending on the purpose, you may add more cement or less compared to the ratio of aggregates.
- Hope this helped.
What is the standard thickness of concrete?
4 to 6 inches
Most specifications for retail or commercial concrete slabs specify 4 to 6 inches of thickness. Owners and contractors have historically disputed whether a poured slab meets a specification because of its thickness.
What is the minimum depth for footing?
Depth of Footings Footings should extend to a minimum depth of 12 inches below previously undisturbed soil. Footings also must extend at least 12 inches below the frost line (the depth to which the ground freezes in winter) or must be frost-protected.
What is blinding concrete?
Blinding concrete plates are laid to level the surface of a footing trench. These concrete plates also serve as under layers for ceramic tiling and flooring purposes. Compared with structural concrete, blinding concrete can withstand much lower pressure and is therefore used for lighter duty construction.
How much sand is in a blinding layer of concrete?
That is 1 part cement, 2 parts sand, 3 parts gravel, and 0.5 part water. What is a blinding layer concrete? Concrete blinding is the process of pouring a thin layer of concrete over the floor of a new building; this can be over the hardcore or over the foundation itself.
What is the ratio of blind mix concrete?
Concrete blinding is just 2″ of regular concrete mix. It’s made up of your normal ratio of cement mix, aggregates, and water. People try to use finer aggregates for this purpose because of the thickness required. It’s usually done on site through hand mixtures. Accordingly, what is lean mix concrete ratio?
What size polyethylene sheet do I need to blind concrete?
The polyethylene sheet should be of sufficient size so that the sheeting shall be returned up the outside faces of the concrete and suitably sealed. The responsibility for blinding concrete works rests primarily with the Site Engineer and Discipline Foreman with assistance from and audit by the Site Agent and inspectors.