Aggregate Impact Value Apparatus (AIV)
NL 1002 X / 002

Standard: BS 812, NF P18-574

Aggregate Impact Value Apparatus (AIV)

The Aggregate Impact Value Apparatus (AIV) is used to determine the aggregate impact value by measuring the resistance of an aggregate to sudden impact or shock loading, which may vary from its resistance to gradually applied compressive loads on construction materials such as crushed stones and gravel. It is determined by subjecting a sample of aggregate to a standard amount of impact, usually in a testing machine, and then measuring the percentage of fines produced.

A high AIV indicates a weak aggregate, meaning it is more likely to break under impact loading. This test is commonly used in the construction industry to assess the suitability of aggregates for use in pavement construction, where the ability to withstand impact is important. The test simulates the impact of vehicle loads and helps assess the aggregate's ability to resist sudden shocks and stresses.

This apparatus is constructed with a strong rigid steel frame and mechanical blow counter.

Features of Aggregate Impact Value Apparatus (AIV)

• Strong Rigid Steel Frame: The apparatus is constructed with a sturdy steel frame to provide stability and durability during testing.
• Mechanical Blow Counter: It is equipped with a mechanical blow counter to accurately count and record the number of impacts applied to the aggregate sample during testing.
• Standardized Impact Testing: The apparatus applies a standardized amount of impact to the aggregate sample, ensuring consistency and repeatability in test results.
• Measurement of Fines Produced: After subjecting the aggregate sample to impact, the apparatus allows for the measurement of the percentage of fines produced. This measurement helps to assess the aggregate's resistance to impact loading.

Technical Specifications:

Unit Consist Of:

Optional Accessories

Features of Aggregate Impact Value Apparatus (AIV)Standard

• BS 812: Provides methods for the sampling and testing of aggregates from various sources, including natural and recycled materials, for use in construction. It covers procedures for determining the physical and mechanical properties of aggregates, such as particle size distribution, density, water absorption, and resistance to fragmentation, including the Aggregate Impact Value (AIV) test.
• NF P18-574: Specifies methods for testing aggregates used in construction, including procedures for determining particle size distribution, water absorption, and resistance to fragmentation. It may include tests similar to those outlined in BS 812, adapted to French regulatory requirements and industry practices.

Test Procedure of Aggregate Impact Value Apparatus (AIV)

• Sample Preparation: Obtain a representative sample of the aggregate to be tested. The sample should be large enough to allow for several tests to be conducted.

• Cleaning and Drying: Clean the sample to remove any dust, dirt, or other contaminants. Then, dry the sample in an oven at a temperature of 100-110°C until it reaches a constant weight. This ensures that the moisture content of the sample is minimized.

• Preparation of Test Apparatus: Set up the AIV testing apparatus on a stable surface. Ensure that the apparatus is properly calibrated and in good working condition.

• Weighing of Sample: Weigh the dried aggregate sample to an accuracy of 0.1% of the total weight of the sample and record the weight.

• Applying Impact: Place the sample in the AIV testing machine and apply a standard amount of impact. The impact may be applied using a hammer or mechanical device that delivers a controlled blow to the sample.

• Measuring Fines Produced: After applying the impact, sieve the sample through a specified set of sieves to separate the fines from the coarse aggregate. Weigh the fines retained on each sieve to determine the percentage of fines produced.

• Calculation of Aggregate Impact Value: Calculate the Aggregate Impact Value using the formula: AIV= (Weight of Fines Produced (g) / Weight of Original Sample (g)) ×100

• Interpretation of Results: Interpret the AIV value obtained from the test. A higher AIV indicates a weaker aggregate, while a lower AIV suggests a stronger aggregate with better resistance to impact loading.

• Reporting: Record all relevant details of the test procedure, including sample identification, test conditions, and results obtained. Report the Aggregate Impact Value along with any other relevant findings.

• Quality Control: Ensure that the test procedure follows established standards, such as BS 812 or NF P18-574, to maintain consistency and reliability in testing results. Regular calibration and maintenance of the testing apparatus are essential for accurate and dependable results.