Скачать или смотреть Aggregate Crushing Value CONCRETE TECHNOLOGY MODULE 1 3 3

Aggregate Crushing Value:
Resistance against incremental compressive load:
The crushing value of aggregate is restricted to 30% for concrete used for roads and pavement and 45% for other RCC(Reinforcement Cement Concrete) Structure.



Methodology:

1. Sieve the sample of aggregate passing 12.5mm and retained on 10mm sieve.

2. Fill the sample in cylindrical mould in three steps tamping each 25 times.

3. Place the mould under a load of 40 ton (40000kg) in 10 min.

4. Sieve the aggregate sample through 2.36mm sieve.

5. Percentage of crushed aggregate through 2.36mm sieve is known as aggregate crushing value.



Refer the web module to understand the above test to greater depth in easy steps.



DO YOU KNOW?

The crushing value of aggregate is rather insensitive to the variation in strength of weaker aggregate. This is so because having been crushed before the application of full load of 40 tons, the weaker material become compacted, so that the amount of crushing during later stages of the test reduced. For this reason, a simple test knows as ’10 Percent fines value’ is introduced to give better picture about the strength of such aggregate.

We will learn about this test, later in module.