FINENESS MODULUS OF AGGREGATE – WHAT, WHY & HOW

Fineness Modulus of Sand

What is Fineness Modulus of Aggregate? Fineness modulus is an empirical factor obtained by adding the cumulative percentages of aggregate retained on each of the standard sieves ranging from 80 mm to 150 micron and dividing this sum by 100. Why to Determine Fineness Modulus? Fineness modulus is generally used to get an idea of … Read more

WHAT IS ANGULARITY NUMBER OF AGGREGATE?

Angularity Number Angularity number is used to give an indication of shape of aggregate. The concept of angularity number was suggested by Shergold. It gives a qualitative representation of shape of aggregate. Angularity Number Test Angularity number test gives an idea of how angular the aggregate is. This is based on the percentage of voids … Read more

AGGREGATE IMPACT VALUE TEST-10+ IMPORTANT NOTES TO REMEMBER

Aggregate impact value test gives an indication of aggregate’s toughness property (i.e. property of a material to resist impact) Aggregate impact values are used to classify the stone aggregates with respect to toughness property as given below. Aggregate impact value (%) Toughness Properties <10 Exceptionally tough / Strong 10 – 20 Very tough / Strong … Read more

DETERMINATION OF LIGHT WEIGHT PIECES (COAL & LIGNITE) IN AGGREGATE (IS-2386-PART-2)

Objective To determine the approximate percentage of light weight pieces (i.e. coal & lignite) in aggregate by means of sink-float separation in a heavy liquid of suitable specific gravity. Apparatus Name Capacity Least Count Balance 500 g 0.1 g Balance 5000 g 1 g Oven 100 to 1100C   Sieve 300 micron, 4.75 mm   … Read more

HOW TO FIND OUT QUANTITY OF SILT IN FINE AGGREGATES IN THE FIELD?

Silt content in Fine Aggregates

Objective To determine quantity of silt in fine aggregates in the field Theory There are two types of harmful substances preset in fine aggregates i.e. organic matter produced by decay of vegetable matter and/or clay and silt, which form coating thus preventing a good bond between cement and the aggregates. If present in large quantities, … Read more

BULKING OF FINE AGGREGATE – WHAT, WHY & HOW?

percentage of bulking of sand with moisture content

The volume increase of fine aggregate due to presence of moisture content is known as bulking. Fine sand bulks more as compared to coarse sand. Extremely fine sand particularly the manufactured fine aggregate bulks as much as about 40%. Note: Fine aggregate do not show any bulking when it is absolutely dry or completely saturated. … Read more

SPECIFIC GRAVITY & WATER ABSORPTION OF AGGREGATE (IS:2386-Part 3-1963)

Objective For determination of specific gravity & water absorption of aggregates.  Reference Standards IS : 2386 (Part 3) – 1963 – Method of test for aggregates for concrete (Part I) Particle size and shape. Equipment & Apparatus Wire basket Oven (3000c) Container for filling water and suspending the basket An air tight container Balance[0-10 kg] … Read more

ANGULARITY NUMBER OF COARSE AGGREGATE (IS:2386-Part 1-1963)

Objective For determination of angularity number of coarse aggregates.  Reference Standards IS: 2386 (Part I) – 1963 – Method of test for aggregates for concrete (Part I) Particle size and shape. Equipment & Apparatus Balance (0-10kg) Sieves (20,16,12.5,10,6.3,4.75mm) Metal cylinder Tamping rod Scoop  Test Sample Preparation The test sample consist of aggregate retained between the … Read more

PARTICLE SIZE DISTRIBUTION OF AGGREGATES (IS:2386-Part 1-1963)

Objective For determination of particle size distribution of fine, coarse and all-in-aggregates by sieving.  Reference Standard IS : 2386 (Part I) – 1963 – Method of test for aggregates for concrete (Part I) Particle size and shape.  Equipment & Apparatus Balance (0-10kg) Sieves Oven Test Sample Preparation The sample is prepared from the larger sample … Read more