What are the properties of concrete?

Answer 1

Concrete is an artificial conglomerate stone made essentially of Portland cement, water, and aggregates. When first mixed the water and cement constitute a paste which surrounds all the individual pieces of aggregate to make a plastic mixture. A chemical reaction called hydration takes place between the water and cement, and concrete normally changes from a plastic to a solid state in about 2 hours. Thereafter the concrete continues to gain strength as it cures.

Concrete has almost no tensile strength (usually measured to be about 10 to 15% of its compressive strength), and for this reason it is almost never used without some form of reinforcing. Its compressive strength depends upon many factors, including the quality and proportions of the ingredients and the curing environment. The single most important indicator of strength is the ratio of the water used compared to the amount of cement. Basically, the lower this ratio is, the higher the final concrete strength will be.
The ingredients of concrete can be proportioned by weight or volume. The goal is to provide the desired strength and workability at minimum expense. Sometimes there are special requirements such as abrasion resistance, durability in harsh climates, or water impermeability, but these properties are usually related to strength.

Answer 2

Desired Properties of Concrete

1. The concrete mix is workable. It can be placed and consolidated properly by yourself or your workmen.

2. Desired qualities of the hardened concrete are met: for example, resistance to freezing and thawing and deicing chemicals, watertightness (low permeability) , wear resistance, and strength. Know what you are trying to achieve with the concrete.

3. Economy. Since the quality depends mainly on the water to cement ratio, the water requirement should be minimized to reduce the cement requirement (and thus reduce the cost).

Take these steps to reduce the water and cement requirements:

use the stiffest mix possible

use the largest size aggregate practical for the job.

Use the optimum ratio of fine to coarse aggregate.

Discuss how to achieve your goals for the concrete with your ready mix supplier.

Answer 3

Good: Durable, takes compressive loads, easy to manufacture, strong
Bad: Poor in tension, can suffer from chemical attack, mix requires proper design

Answer 4

Portland cement, water, and aggregates

Answer 5

concrete is made from cement and ballast......ballast is rough sand and stone chippings

Answer 6

sand , cement and aggregate .

Answer 7

hard, smooth, sensitive, throbbing


no.....just hard and smooth

Answer 8

It's hard!!!!!!!