Can an abstract class may not contain concrete methods? An abstract class may or may not contain abstract methods. A concrete class cannot contain an abstract method. An abstract class cannot be declared as final. A concrete class can be declared as final.
Can abstract classes have concrete methods? Abstract classes are similar to interfaces. You cannot instantiate them, and they may contain a mix of methods declared with or without an implementation. However, with abstract classes, you can declare fields that are not static and final, and define public, protected, and private concrete methods.
Can abstract class contain only concrete methods? A class can implement multiple Interfaces. Abstract Class: Only Abstract methods have to be implemented by the subclass. An Abstract class can have normal methods with implementations.
Can an abstract class have no abstract methods? Yes we can have an abstract class without Abstract Methods as both are independent concepts. Declaring a class abstract means that it can not be instantiated on its own and can only be sub classed. Declaring a method abstract means that Method will be defined in the subclass.
Can an abstract class may not contain concrete methods? – Related Questions
How to place anchor bolts in concrete?
If you are using anchor bolts for concrete slabs or foundations it’s important to place the bolt in the concrete so it’s in the center of the wall. For 2 x 6 walls, the bolt would be 2 3/4 inches from the outer edge and for 2 x 4 walls the anchor bolt would be 1 3/4 inches from the edge.
Can you mop concrete floors?
As long as it is properly sealed, concrete is non-porous, making it resistant to stains and exceptionally easy to clean and maintain. … For further protection against stubborn stains and dirt, it is also recommended that you apply a mop down floor wax designed for sealed concrete floors.
Do u need concrete sealer on new concrete?
If your concrete is new, you’ll need to let it cure; wait at least one month before applying sealer. Before you apply it, check the weather. Sealer needs to be applied in dry conditions because it won’t adhere to damp concrete.
Why does temperature drop in a concrete building?
Temperature changes may be caused by environmental conditions or by cement hydration (the exothermic chemical process in which the cement reacts with the water in a mixture of concrete to create the calcium silicate hydrate binder and other compounds).
Can you put a fiberglass pool inside a concrete pool?
So in closing can you install a fiberglass pool inside of an existing pool, why yes you can.
What do you call the cuts in concrete floors?
Contraction joints (sometimes called control joints) are used in unreinforced and lightly reinforced slabs-on-ground to minimize random cracking. By creating straight-line weakened-planes in concrete, contraction joints “control” the cracking location by inducing cracks at predetermined locations.
Can you pressure wash stained concrete?
You can use a water hose or power washer. If it is waxed then follow the instructions for Interior. If it is not waxed, then since there is no wax to protect the outdoor concrete sealant, it will wear and need to re applied occasionally.
How do you make lightweight concrete?
Using less sand can make the product lighter, but it can also make the concrete weaker structurally. A simple recipe for basic lightweight concrete is to combine 8 parts sand, 8 parts cement and 8 parts perlite to 5 parts water.
How to set up rebar for concrete?
When you’re joining two concrete slabs, connect the two with rebar to keep them at the same height. Drill the holes as deep as you can (the entire length of the bit) so the rebar fits snugly into the holes. Insert chunks of rebar and tie them into the grid.
How do you fix a crumbling concrete step?
When you’re joining two concrete slabs, connect the two with rebar to keep them at the same height. Drill the holes as deep as you can (the entire length of the bit) so the rebar fits snugly into the holes. Insert chunks of rebar and tie them into the grid.
How do u get fence paint off concrete?
If you accidentally get fresh paint on a concrete surface, it’s easy to clean up: just cover the surface with water and then use a hard-bristled brush and detergent to scrub it away.
Can we recycle concrete?
Old, unneeded concrete can be recycled and used to create recycled aggregate. … Recycled concrete can also be used to create 2”-4” recycled stone. This product is typically used for site stabilization, bottom layer road base, and backfill. Besides stone, recycled concrete can also be used to create engineered fill sand.
Can i use quick concrete in the cold?
PRECAUTIONS • Mix only as much material as can be placed in 20 minutes. Because of the rapid setting time, special precautions must be taken, as set times will fluctuate in extremely hot or cold weather. … Use hot water when mixing in severely cold weather.
How are iron oxide concretions formed?
The formation of iron oxide concretions involves interactions of Fe bearing reducing fluid and oxidized groundwater resulting in precipitation of metastable iron phases (Chan et al. 2000, 2005; Potter et al. 2011). The metastable iron phases gradually dehydrate to form stable hematite (Chan et al.
How deep should a concrete garage base be?
For most domestic garages, a six-inch slab of concrete will be sufficient. It is only when a space will see constant traffic from much heavier vehicles that a concrete slab of more than six inches would be needed.
Is carpet or tile best over concrete floor?
Carpet may not be the most obvious choice, but thousands of houses across the country actually have carpet over concrete. To install carpet, you’ll need a waterproof barrier and a layer of padding on top of your concrete. Ceramic tile is waterproof and suitable for wet areas like kitchens and bathrooms.
When is concrete fully cured?
By seven days, your concrete should be cured to at least 70 percent of its full strength. You will probably be able to drive on it without damaging it, although you may want to hold off on rolling heavy equipment over it. In 28 days, you can treat your concrete as fully hardened.
How do you drill a screw into concrete?
The quickest, easiest way to drill into concrete is with a hammer drill, which uses both bit rotation and concussive blows to bore the holes. If you don’t own a hammer drill you can use a standard corded electric drill or cordless battery-powered drill, but it’ll take at least twice as long to drill each hole.
How to remove vct tile from concrete?
The best way to accomplish both VCT and mastic removal is with a ride-on scraper. This makes quick work of the removal process and removes most of the adhesive with the tile. Hand scraping will leave most of the mastic on the floor which will have to be dealt with with grinders or other concrete tooling.
Why is air entrained concrete good to use?
The primary use of air-entraining concrete is for freeze-thaw resistance. The air voids provide pressure relief sites during a freeze event, allowing the water inside the concrete to freeze without inducing large internal stresses.
Can you use construction screws in concrete?
Can you screw directly into concrete? Concrete screws are a quick and convenient way to fasten to concrete. The best thing about these screws is that you can screw directly into concrete without any need for hammering or an anchor or shield to install. All you have to do is drill a hole and drive in the screw.