**ACCELERATED CURING METHOD** is used to get early high compressive strength in concrete. This method is also used to find out 28 days compressive strength of concrete in 28 hours. (As per IS 9013-1978-Method of making, curing and determining compressive strength of accelerated cured concrete test specimens).

Accelerated curing is useful in the prefabrication industry wherein high early age strength enables the removal of the formwork within 24 hours thereby reducing the cycle time resulting in cost saving benefits.The most commonly adopted curing techniques are **steam curing at atmospheric pressure, warm water curing, boiling water curing and autoclaving.**

**Compressive strength test using Accelerated curing method:**

1. After the test specimens (whose 28 days strength to be determined) have been made, store it in moist air of at least 90 percent humidity for 23 hours + 15 min.

2. Cover the specimens with flat steel cover plate to avoid distortion during the use.

3. Carefully and gently lower the specimens into the curing tank and shall remain totally immersed for a period of 3½

Hours + 15 min.

4. The temperature of water in the curing tank shall be at boiling (100 ^{o}C) when the specimens are placed.

5. After curing for 3 ½ hours in boil water, the specimen shall be carefully removed from the boiling water and cooled by immersing in cooling tank at 27 +2^{o}C for 2 hrs.

6. After cooling remove the specimens from the mould and tested for its accelerated compressive strength (Ra) in N/mm^{2}.

**7. The 28 days can be found out using following formula.**

Predicted 28 days compressive strength = R28 = 8.09 + 1.64 Ra, where Ra is accelerated compressive strength and R28 is predicted compressive strength at 28 days

Learn more about accelerated curing. **Download this file**- **Accelerated Curing Methods**

Kulwant Singh

Compressive strength test using Accelerated curing method:gives wrong results by Predicted 28 days compressive strength = R28 = 8.09 + 1.64 Ra, where Ra is accelerated compressive strength and R28 is predicted compressive strength at 28 days.

Gopal Mishra

then what is the correct formula to relate the accelerated curing method and 28 days compressive strength test?

Rahul Vishwakarma

I think it is right formula, to get results by accelerated (boiling water method) of 28 days. BUT What's the regression equation funda of 8.09 + 1.64, how that came?

க. மாரி முத்து

oops.. there is no downloadable file for accelerated curing method

Damilola Olaleye

When dealing with curing of cube test u have to ensure proper step in order to detect the compressive strength test. like using three brand of cement i.e elephant,dangote,pure chem. this three cement are different in there work done.

after carry out the test for 7days,14 days and 28days in lab,u will ensure that is well place in the curing tank for 7,14 and 28days to ensure the compressive strength of each brand of the cement by crushing machine. also take the proper record of each brand.

Damilola Olaleye

u can detect this in the lab.by making use of curing tanks to detect each brand u place inside the curing tank

Sreenivas Tummala

Is there any specific IS code for Accelerated curing method for compressive strength test

Hussam Eldin

The mentioned formula should include somthing about the temperature used ,as the temperature is the main culprit in increasing the hydration rate hence the strength…unles a specific temperature is always used for this kind of curing …

Chander Mohan

how to get rid of shrinkage cracks in this process in air entrained admixtures used then it is not up to the mark and not within suitable limits