How should concrete test cylinders be cured?

For initial curing, store cylinders for a period up to 48 hours in a temperature range from 60 to 80° F and protect from moisture loss. For concrete with a specified strength of 6,000 psi or greater, the initial curing temperature range is between 68 and 78° F.

How much is the curing time period?

Since all desirable properties are improved with curing, the period should be as long as practical. For most concrete structures, the curing period at temperatures above 5º C (40º F) should be a minimum of 7 days or until 70\% of the specified compressive or flexural strength is attained.

What happens when concrete fails?

The resulting pressure created inside the concrete will cause cracking and severe deterioration to the structure over time. If the concrete and rebar are not protected, the salts will eventually reach the depth of the rebar and cause corrosion.

How do you find the compressive strength of a concrete cylinder?

Calculating Compressive Strength The formula is: CS = F ÷ A, where CS is the compressive strength, F is the force or load at point of failure and A is the initial cross-sectional surface area.

Why cylinder strength of concrete is less than cube strength?

Cylinder strength is lower because height to diameter ratio is 2 and at cube height to side ratio is 1. Also, friction at upper and lower plane of specimen with plates is different so that influences too.

How do you cure concrete specimens?

In both methods, the curing place must be firm, within ¼ in. of a level surface, and free from vibrations or other disturbances. Maintain initial curing temperature of 16 to 27° C (60 to 80°F) or 20 to 26°C (68 to 78°F) for concrete with strength of 40 Mpa (6000 psi) or more. Prevent loss of moisture.

What to do when the concrete cylinder strength is low?

If the strength of the concrete was low, then use suitable strengthening and rehabilitation techniques to increase the load-carrying capacity of the structure. The concrete cylinder strength at 28 days indicates whether the strength characteristics of the concrete used in the construction of a structure are good enough or not.

When to test concrete cubes and cylinders?

It is mandatory to test the concrete cubes or cylinders at the age of 28 days as per almost all building code requirements. Now, once your 7-day test and even your 14-day test have passed, you will then wait for the 28-day test.

What happens if 28 days concrete cube test results fail?

If 28th days concrete cube test results fail check if the result of all 7 days cubes is the same. If even one passes the acceptable criteria you are sure that the concrete mix is OK. Now the question of workmanship. Even if one of the cubes is OK wait for a 28 Day result.

How long does it take to test the strength of concrete?

Strength of concrete is generally tested after 28 days as concrete cube strength or concrete cylinder strength.