Contents
- 1 How long can you wait to cut concrete?
- 2 What happens if you don’t cut concrete?
- 3 How big can a concrete slab be without expansion joints?
- 4 Should you saw cut concrete?
- 5 Do concrete driveways need expansion joints?
- 6 How do you cut a concrete slab by hand?
- 7 Why do they cut lines in concrete?
- 8 Do concrete saws cut rebar?
- 9 How do you pour concrete into a saw cut slab?
- 10 When should you cut expansion joints in concrete?
- 11 What material is used for expansion joints in concrete?
- 12 When should you use expansion joints in concrete?
- 13 How deep will a 12 inch concrete saw cut?
- 14 How do you keep concrete from cracking?
- 15 How fast does a walk behind concrete saw cut?
How long can you wait to cut concrete?
In hot weather conditions, saw cutting may start as soon as four hours after the concrete is poured. In cooler weather, sawing may not start for 12 hours after pouring. 1 The best way to determine whether the slab is ready is to make trial cuts to check for raveling.
What happens if you don’t cut concrete?
In hot weather, concrete might crack if joints are not cut within 6-12 hours after finishing concrete. In this condition, if you don’t want to use a grooving tool to cut joints, there are early-entry dry-cut lightweight saws that can be used almost immediately after finishing.
How big can a concrete slab be without expansion joints?
Usually, expansion joints should be no farther apart than 2 to 3 times (in feet) the total width of the concrete (in inches). So for a 4 inch thick concrete slab, expansion joints should be no more than 8 to 12 feet apart.
Should you saw cut concrete?
In addition to depth of contraction joints, saw cut timing is critical to minimize random cracking. In general, saw cut joints should be installed as soon as the concrete is sufficiently hard to resist tearing and raveling and before random cracking occurs.
Do concrete driveways need expansion joints?
Every concrete slab, inside (basements, garages, etc.) or outside (driveways, patios, entries, etc.) are required to have joints every eight feet horizontally and vertically. Expansion Joints provide space between concrete slabs as a buffer for expansion on hot days and contraction when it is cold.
How do you cut a concrete slab by hand?
If your cut doesn’t need to be exact, use a cold chisel and hand sledge to cut the concrete. Score the length of the cut three or four times with the chisel. A circular saw with a masonry blade can also be used to either score or completely cut through the block.
Why do they cut lines in concrete?
To prevent sidewalks from cracking in random spots and breaking apart, builders make lines in sidewalks. The technical term for sidewalk lines is contraction joints. Contraction joints are placed in fresh concrete before the concrete dries and has a chance to create its own joints, which we call cracks.
Do concrete saws cut rebar?
Rebar provides a strong net that the concrete sets around. Major cutting of concrete should be left to the professionals, but a minor job around the home can be done with the right equipment. Many home improvement stores rent concrete wet cutters with diamond blades, which are needed for cutting through the rebar.
How do you pour concrete into a saw cut slab?
How to re–pour concrete in saw–cut slab?
- hammer-drill holes sideways into the cut surfaces of the concrete to make holes 3-inch deep for dowels (3/8 rebar that I already have sitting around)
- remove all loose material from the dirt hole.
- clean rocks and concrete out of the fill dirt.
When should you cut expansion joints in concrete?
Joints should be sawed as soon as the concrete will withstand the energy of sawing without raveling or dislodging aggregate particles. For most concrete mixtures, this means sawing should be completed within the first six to 18 hours and never delayed more than 24 hours.
What material is used for expansion joints in concrete?
Minimize Concrete Cracking and Damage with Expansion Joints. ASPHALT EXPANSION JOINT is composed of a blend of asphalts, vegetable fibers, and mineral fillers formed under heat and pressure between two asphalt-saturated liners. It is waterproof, permanent, flexible, and self-sealing.
When should you use expansion joints in concrete?
Expansion joints are put in place before the concrete is poured. Expansion joints are used to allow the slab to move and not put stress on whatever it abuts. These joint are placed where a slab meets a building, where a slab meets another slab, and where a pool deck meets the coping.
How deep will a 12 inch concrete saw cut?
| Cured Concrete/Asphalt Blades | ||
|---|---|---|
| Diameter | Cutting Depth* | |
| 12“ | (305mm) | 4″ |
| 14″ | (356mm) | 5″ |
| 18″ | (457mm) | 7″ |
How do you keep concrete from cracking?
If you’re having new concrete poured consider the following ways to prevent cracking:
- Start with a sound subgrade. Make sure the subgrade is compacted.
- Modify the concrete mix. Use a low water-to-cement ratio.
- Install joints. Be active in deciding where control joints will be placed.
- Properly cure the concrete.
How fast does a walk behind concrete saw cut?
Cutting is done dry with the green concrete saws. Like regular concrete saws, these saws range in size and in- tended use. Blade speed is fast, usually between 5,400 and 5,800 rpm.