Yarmouk University
Al-Hijjawi Faculty for Engineering Technology
Civil Engineering Department
Materials of Construction Laboratory CE 326/Spring Semester 2023-2024
Experiment Name:Specific Gravity and Absorption of Aggregate
Student Name:Eman Qasem ALqudah
Student Number:2021990007
Submitted to: Eng. Saeed K. Thiabat
Submission Date:18.apr.24
Introduction
The specific gravity of an aggregate is generally required for calculations in connection with cement concrete design
work for determination of moisture content and for the calculations of volume yield of concrete. The specific gravity
also gives information on the quality and properties of aggregate. The specific gravity of an aggregate is considered to
be a measure of strength of quality of the material. Stones having low specific gravity are generally weaker than those
with higher specific gravity values. The bulk density of an aggregate is used for judging its quality by comparison with
normal density for that type of aggregate. It is required for converting proportions by weight into proportions by
volume and is used in calculating the percentage of voices in the aggregate.
1. Specific gravity is the weight of aggregate relative to the weight of equal volume of water.
2. Void ratio is the ratio of volume of voids to the volume of solids in an aggregate.
3. Percentage of voids or porosity is the ratio of volume of voids to the total volume of a sample of an aggregate.
4. Bulk density or unit weight is the weight of material per unit volume.
Objectives
The primary objective of this experiment is to determine:
1.The bulk specific gravity (dry and saturated surface dry)
2.The apparent specific gravity
3.The absorption capacity
of a provided aggregate sample.
Materials
1.Course Aggregate.
2.Fine Aggregate.
3.Water.
Apparatus
1.Oven.
2.Sieves.
3.Balance.
4. Wire bucket.
5.Pycnometer.
6.Sample spiltter.
Procedure
1. Begin by obtaining a sample of coarse aggregate using a sample splitter.
2. Sieve the sample using 4.75mm sieves, disregarding any materials that pass through the No. 4.75 sieve.
3. Wash the sample thoroughly to eliminate any dust particles.
4. Dry the sample with towel.
5. Obtain the required weight of the sample in its saturated surface dry (S.S.D) condition.
6. Immediately after weighing, place the S.S.D sample in a sample container (Basket) and determine its weight in water Ensure
to eliminate all entrapped air before weighing by gently shaking the container while immersed.
7. Dry the test sample to a constant weight in oven at a temperature of 150°C. Allow it to cool in ambient air for 1 to 3 hours, or
until the aggregate has reached a temperature suitable for handling, and then weigh it.
8.Weigh a sample from Fine Aggregate.
9.Carefully pour of any excess water, ensuring not to lose any fne particles. Spread the sample on a fat, non-absorbent surface exposed to
a gentle current of warm air.
10.Stir the sample frequently to ensure uniform drying until it reaches a saturated surface dry condition. Use the cone test to check for
surface moisture.
11.Secure the mold frmly on a smooth, non-absorbent surface with the larger diameter facing downwards. Fill the mold with a portion of
the partially dried fne aggregate, then compact for 25 times.
12.Obtain a pycnometer and fll it with distilled water, ensuring no air bubbles are trapped.
13.Weigh the pycnometer with water (Wpyc + water).
14.Introduce the oven-dried aggregate (Ws dry) into the pycnometer.
15.Fill the pycnometer with distilled water ensuring all aggregate particles are submerged. Eliminate any air bubbles by rolling the
pycnometer over 45°.
16.Weigh the pycnometer with aggregate and water (Wpyc + agg + water).
Data and Result
Course Aggregate
Fine Aggregate
Sample Number
Weight
Oven dried-A
735
Saturated, surface-dry-B
765
Submerged in water-C
462
Sample Number
Oven dried-A
Pycnometer filled with Water
Weight
158
710.5
to the calibration mark-B
Submerged in water-C
809.7
Saturated, surface-dry-D
165.5
Properties
Course aggregate
Fine aggregate
Bulk S.G (OD)
2.425
2.383
Bulk S.G (SSD)
2.524
4.496
Apparent S.G
2.692
2.687
Absorption
4.081%
4.748%
Sample of Calculations: (For your group only)
For Coures Aggregate
Bulk �.�(SSD)=B/(�−C)
=765/(765-462)
=2.524
For Fine Aggregate
�pperant �.� = �/(�+�−C)
=158÷(158+710.5-809.7)
=2.687
Discussion
1-What is the purpose of determining the specifc gravity and bulk density of aggregates?
Specifc gravity and bulk density are important properties of aggregates used in concrete design. Specifc gravity helps determine:
Moisture content: Needed for accurate proportioning of concrete ingredients.
Volume yield of concrete: Essential for estimating the amount of concrete produced from specifc quantities of materials.
Aggregate quality: Generally, higher specifc gravity indicates denser and potentially stronger aggregates.
Bulk density is used for:
Converting weight to volume: Helps translate weight-based material quantities to volumes needed for mixing concrete.
Calculating void content: Indicates the amount of empty space within the aggregate particles.
2-What were the key fndings from the experiment regarding the specifc gravity and absorption capacity of the fne
and coarse aggregate samples?
A: The experiment results showed:
Higher bulk specifc gravity (SSD): Coarse aggregate (2.524) compared to fine aggregate (2.383).This suggests the coarse aggregate might
be denser.
Higher apparent specifc gravity: Both fne (2.687) and course (2.692) aggregates had similar values.
Higher absorption capacity: Fine aggregate (4.748%) compared to coarse aggregate (4.081%). This indicates the fine aggregate absorbs
more water.
Conclusion
Through this experiment, the bulk specific gravity (SSD), apparent specific gravity, and
absorption capacity of the provided fine and coarse aggregate samples were successfully determined.
These findings offer valuable insights for concrete mix design and quality assessment. Notably, the
higher bulk specific gravity of the coarse aggregate suggests potential denser characteristics, which
could contribute to stronger concrete. Additionally, the greater absorption capacity of the fine
aggregate necessitates consideration during mix design to accommodate additional water
requirements.