Kurdistan Regional Government-Iraq Ministry of Higher Education and Scientific Research

1. Kurdistan Regional Government-Iraq • Ministry of Higher Education and ScientificResearch • Universy of Salahaddin – Hawler • College of Engineering • Department of Civil Engineering • Concrete Testing Lab • Academic year (2018-2019) • Prepared by: Barzan Omar, M.Sc. • (2015-2016)

2. Test No. 1 • Specific Gravity of Cement

3. Content • Introduction • Objective • Apparatus • Materials • Procedures • Calculation • Data Sheet • Question Concrete testing lab

4. Introduction • The world is composed of various materials and most widely construction material used in the world until now that the human use to construction their houses, buildings and any other structures is concrete. • Concrete is a composed material composed of coarse granular material (aggregate or filler) embedded in hard matrix of material (cement or binder) that fills the spaces between the aggregate particles and glue them together. • In ancient times, Egyptians, Greeks, and Romans used the cementitious materials to glue the elements of the buildings for example, Egyptians used burning gypsum as cementitious materials, Greek and Romans used burning lime stone as cementitious materials. • Concrete can be represented simply as Filler + Binder. Concrete Concrete testing lab

5. Introduction (Cement + Water) Cement Paste + Mortar Concrete Fine aggregate + Coarse aggregate Cement Water Coarse and fine Aggregate Concrete testing lab

6. Introduction • Cement is a fine, soft powdery-type substance that exhibits characteristic properties of setting and hardening when mixed to a paste with water. • There are many types of cement that depends on the chemical composition their gradients. • Portland Cement primly consists of : Concrete testing lab

7. Introduction • Specific Gravity (S.G): it can be defined as ratio of the density of a substance to that of a standard substance (density of water), and has no unit. • The specific gravity also gives the meaning of submersion of fraction of an object in water or denoted how many times a substance heavier as water. • For example, if the specific gravity of an object is 0.2, it means that the 20 percentage of body of the object is submerged in the water. • Density: It is the mass per unit volume. And the symbol most often used for density is • Mass: It is a measurement of how much matter is in an object and the symbol most often used for mass is m. Concrete testing lab

8. Introduction • The specific gravity of cement can be determined by indirect method. • Archimedes principle “The buoyant force exerted on a body immersed in a fluid is equal to the weight of the fluid the body displaces” can be used to determine the volume of substance by immersed in a liquid. • The water ( at ) is usually used as standard substance to determine the density of materials. • For an object less dense than water: Concrete testing lab

9. Introduction • For an object more dense than water: • Kerosene, free of water, or naphtha, having a density greater than should be used instead of water. • The specific gravity of Portland cement is generally around 3.15 while the specific gravity of Portland blast-furnace slag around 2.9. • The significance of this test can be concluded as follow: • It can be used in mixture proportion calculations. • it can be used to convert mass of cement to volume Concrete testing lab

10. Objective • The objective of this test is to determine the specific gravity of cement by Pycnometer method. Concrete testing lab

11. Apparatus • Pycnometer, a flask or other suitable container into which the cement can be readily • Weighing balance accurate up to 0.01 gm • Metal or glass funnel. • scoop Concrete testing lab

12. Materials • Cement sample • Distilled water • Kerosene Concrete testing lab

13. Procedure • Take samples of cement approximately 50, 60, 70 , 80 gm. Let be W1. • Weight the empty Pycnomenter, let be W5. • Calibrate a specific gravity flask Pycnometer by filling with Kerosene oil () to calibration line. Weigh the Pycnometer filled with kerosene to the nearest 0.01g let be W2. • Place sample of cement using funnel into the dry, empty Pycnometer and fill with kerosene (regulated at 23 + 1.0 ) to 90 % Pycnometer capacity. • Manually roll, invert, and agitate the Pycnometer to eliminate air bubbles, repeated for several times. • Fill the Pycnometer with kerosene to the calibration line ,and weigh it to the nearest 0.01g. Let be W3. • Empty ,clean and dry the Pycnometer, then fill it with water up to the specified limit. Record the weight let be W4. Concrete testing lab

14. Calculation • There are two steps to determine the density of cement, first determine the density of kerosene, then calculate the density of cement. • The weights obtained in the procedures: • W1: mass of Cement. • W2: mass of Pycnometer + Kerosene. • W3: mass of Pycnometer + Kerosene + Cement. • W4: mass of Pycnometer + Water. • W5: mass of empty Pycnometer. Concrete testing lab

15. Calculation • Specific Gravity of Kerosene: Where: : specific gravity of kerosene. : density of kerosene (). : density of water (). : mass of kerosene () (W2-W5). : volume of kerosene (weight of water displaced = () in (). Concrete testing lab

16. Calculation • Specific Gravity of Cement: Where: : specific gravity of cement. : density of cement (). : density of water (). : mass of cement () (W1). : volume of cement (weight of kerosene displaced = () in (). Concrete testing lab

17. Calculation Concrete testing lab

18. Data Sheet Concrete testing lab

19. Question • Why kerosene used to determine specific gravity of cement? • What is the effect of moisture from the atmosphere absorbed by particles of cement on specific gravity? • What is the effect of temperature of the weather on the results? • Drive the formula used to calculate the specific gravity of cement. Concrete testing lab