What is Los Angeles abrasion machine?
The Los Angeles abrasion machine is used to measure the degradation of mineral aggregate of standard gradings resulting from a combination of actions including abrasion or attrition, impact and grinding in a rotating steel drum containing a specified number of steel spheres.
How do you calculate the value of abrasion in Los Angeles?
Los Angeles Abrasion Value of Aggregate
- objective. Fig. 1: Balance.
- reference. IS 2386(Part 4):1963 Methods of Test for Aggregates for Concrete- Mechanical Properties. Reaffirmed- Dec 2016.
- procedure.
- calculation. Aggregate Abrassion Value = ((A-B)/A) X 100.
- video. Los Angeles Abrasion Test.
- Download. Download PDF.
What is the principle of Los Angeles abrasion test machine?
Resistance to abrasion of aggregate is determined in laboratory by Los Angeles test machine. The principle of Los Angeles abrasion test is to produce abrasive action by use of standard steel balls which when mixed with aggregates and rotated in a drum for specific number of revolutions also causes impact on aggregates.
Why is LA abrasion test done on aggregate?
The Los Angeles (L.A.) abrasion test is a common test method used to indicate aggregate toughness and abrasion characteristics. Aggregate abrasion characteristics are important because the constituent aggregate in HMA must resist crushing, degradation and disintegration in order to produce a high quality HMA.
What is abrasion in engineering?
Abrasion is a wear mechanism that is caused by the inclusion of hard particles between two sliding or rolling surfaces. Abrasion or abrasive wear leads to material removal by two mechanisms, namely two-body abrasion or three-body abrasion.
What is the abrasion value of coarse aggregate?
This test helps to determine the abrasion value of coarse aggregates as per IS: 2386 (Part IV) – 1963. The apparatus used in this test are Los Angles abrasion testing machine, IS Sieve of size – 1.7mm, Abrasive charge – 12 nos. cast iron or steel spheres approximately 48mm dia.
What is a good LA abrasion value?
Recommended Los Angeles Test Values for Pavements
| Sl. No. | Type of Pavement | Max. permissible abrasion value in % |
|---|---|---|
| 1 | Water bound macadam sub base course | 60 |
| 2 | WBM base course with bituminous surfacing | 50 |
| 3 | Bituminous bound macadam | 50 |
| 4 | WBM surfacing course | 40 |
Which property of material is evaluated using Los Angeles abrasion test?
abrasion resistance
The value obtained from the Los Angeles abrasion test gives an indication of the abrasion resistance of the material. A low LAV indicates that the material has high abrasion resistance. Conversely, a high LAV indicates that the material has low abrasion resistance.
What is abrasion classification?
Abrasions are classified into three types that include linear or scratch abrasions, grazed or brush abrasions, and patterned abrasions. Linear abrasions are caused by tangential forces resulting in denuding of the epidermis.
What is the difference between LA abrasion test and Micro Deval test?
LA Abrasion and Micro Deval tests are both drum tests where degradation occurs by rotating the aggregates together with steel balls. The LA Abrasion tests dry aggregates, while the Micro Deval tests wet or soaked aggregates.
What are the different methods of abrasion testing?
Two common methods of abrasion testing are pin testing and dry sand/rubber wheel apparatus testing. For pin testing, a rotating pin travels along a fixed wear path to produce abrasion on the surface. The dry sand/rubber wheel apparatus test uses a spinning rubber wheel that is positioned a set distance from the sample piece.
What is the La abrasion test?
The Los Angeles (L.A.) abrasion test is a common test method used to indicate aggregate toughness and abrasion characteristics. Aggregate abrasion characteristics are important because the constituent aggregate in HMA must resist crushing, degradation and disintegration in order to produce a high quality HMA.
What is abrasion resistance testing?
abrasion test. The measurement of abrasion resistance, usually by the weighing of a material sample before and after subjecting it to a known abrasive stress throughout a known time period, or by reflectance or surface finish comparisons, or by dimensional comparisons.