ACCELERATED CURING TEST OF CONCRETE (IS:9013-1978)

ACCELERATED CURING TEST OF CONCRETE (IS:9013-1978)

OBJECTIVE

Normally, the strength of concrete is found out after 7 days and 28 days. For some construction activities, it may be too late and need to know the strength earlier. 

REFERENCE STANDARDS

IS: 9013-1978-Method of making, curing and determining compressive strength of accelerated cured concrete test specimen.

EQUIPMENT & APPARATUS

§  Accelerated curing tank

§  Compression Testing                                            
                                                 Accelerated Curing Tank

PROCEDURE

1.                   Prepare the concrete cube specimen and store it in moist air of at least 90% relative humidity and at a temperature of 27+2^oC for 23 hrs + 15 minutes.

2.                 Lower the specimen, into a curing tank with water at 100 ⁰C and keep it totally immersed for 3 ½ hours + 5 minutes

3.                 The temperature of water shall not drop more than 3oC after the specimens are placed and should return to boiling within 15 minutes.

4.                 After curing for 3 ½ hours + 5 minutes in the curing tank, the specimen shall be removed from the moulds and cooled by immersing in cooling water 27+2^oC for a period of at least one hour. 

CALCULATION

The corresponding strength at 28 days can be found out from the following correlation. (It is however suggested that a new specific correlation should be developed for the specific concrete used at site.)

R28 (Strength at 28 days) = 8.09 + 1.64 Ra

Where,

Ra = Accelerated Curing Strength in MPa.           

         

SAFETY & PRECAUTIONS

§  Use hand gloves, safety shoes, while removing containers from curing tank after switching off the curing tank & place sample in machine properly.

§  Equipment should be cleaned thoroughly before testing & after testing.