Recommended
Recommended
More Related Content
What's hot
What's hot (20)
Viewers also liked
Viewers also liked (20)
Similar to Chemistry inveatigatory project on setting of cement
Similar to Chemistry inveatigatory project on setting of cement (20)
Recently uploaded
Recently uploaded (20)
Chemistry inveatigatory project on setting of cement
- 1. CHEMISTRY INVESTIGATORY PROJECT CLASS: 12th By: Akshay Class: X11 A Roll No: 39
- 2. CERTIFICATE Name: Class: Roll No: Institution: This is certified to be the bonafidework of the student in the “Chemistry” Laboratory during the academic year 2016-2017. ………………. Teacher In-Charge ………………… ……………. Examiner’s Signature Principal Date: ……………. Institution Rubber Stamp
- 3. ACKNOWLEDGEMENT I wish to express my deep gratitude and sincere thanks to Principal, Mr. P.V Sudhakaran for his encouragement and for all the facilities that he provided for this project work. I sincerely appreciate this magnanimity by taking me into his fold for which I shall remain indebted to her. I extend my hearty thanks to Mrs. Seema Sharma my chemistry teacher, who guided me to the successful completion of this project. I take this opportunity to express my deep sense of gratitude for his invaluable guidance, constant encouragement, and constructive comments, sympathetic attitude and immense motivation, which has sustained my efforts at all stages of this project work.
- 4. Declaration I do hereby declare that this chemistry project work has been originally carried under the guidance and supervision of Mrs. Seema Sharma, head of chemistry department, Kendriya Vidyalaya No.2 School,Agra Cantt, Agra (U.P).
- 5. Experiment – 1 Aim: To study the setting of mixtures of cement with lime, sand, fly ash etc. Requirements: Beakers, glass rod, weights, small wooden boxes or empty match boxes. Lime, pit sand, river sand, cement, fly ash, rice husk…
- 6. Introduction: Cement is essentially a finely ground mixture of calcium silicates (3Cao.SiO2) and aluminates (3Cao.Al2O3) which sets to a hard mass treated with water. This property makes cement capable of joining rigid masses like bricks, stones, tiles etc. into coherent structures. The cements have property of setting and hardening under water due to certain physicochemical process and are, therefore, called hydraulic cements. During setting of cement, the physical changes taking place are gel formation and crystallization and chemical changes are hydration and hydrolysis. The process of solidification of cement paste involves: (i) setting, and (ii) hardening. Setting is stiffening of the original plastic mass into initial gel formation. After setting, hardening starts due to gradual start of crystallization in the interior of the mass. The strength developed by cement at any time depends upon the amount of gel formed and the extent of crystallization. A mixture of cement, sand, small pieces of stone (gravel) and water is known as concrete and sets to an extremely hard structure.
- 7. When cement is used for construction purposes, it is always mixed with sand and little water to make a pasty material called mortar. Here cement or lime forms the binding material and function of sand is to prevent shrinking and cracking and to increase the bulk, thereby reducing the cost of the mortar. When cement is used as the binding material it is called cement mortar and when lime is used as the binder it is called lime-mortar. Sand in addition to its other functions also increases the adhesive qualities of the binding material. Effect of quality of sand on setting of cement mortar. Sand obtained from different sources has different qualities. For example, sea sand obtained from sea contains some unwanted salts and retards the setting of cement and is unsuitable for making mortar. On the other hand, pit sand obtained from pits in the soil and river sand obtained from river bed are considered excellent for preparing mortar and concrete. Effect of time on setting of cement mortar. Time has an important role on the strength developed by cement mortar. When a cement sand paste in the ratio 1:3 in water is allowed to dry, the strength of the solid mass keeps on increasing with increase in the time given for setting. It acquires nearly full strength in 28 days.
- 8. Procedure:- 1. Prepare the sets of mixtures of various compositions as given in the observation table. 2. Take each of the mixtures in different beakers and prepare their pastes by adding minimum quantity of water. 3. Take 10 empty match-box inner cases and mark them from 1 to 10. 4. Transfer the prepared pastes immediately into the matchboxesand compact themby pressing with hand. 5. Spray water from time to time over the pastes so that they are always moist. 6. Take out the slabs after three days and test for its strength. For that hold a weight of 10g on the hand at a fixed height (say 50 cm above the ground) and drop the weight on the slab. See if the slab breaks or not. If it does not break then take 20g weight and drop it from the same height. This way keeps on increasing the weight and note down the minimum weight required to break the slab. Observations:
- 9. Setting time allowed = 3 days. Note: - The slab should be of 0.5 cm thickness, 2 cm wide and 10 cm long. Sl.No Compositions of Mortar(Ratio composition by volume) Minimum weight required to break the slab. Cement River sand Pit sand Lime Fly ash Rise husk ……..gm. 1. 1 3 **** **** **** **** ……..gm. 2. 1 6 **** **** **** **** ……..gm. 3. 1 **** 3 **** **** **** ……..gm. 4. 1 **** 6 **** **** **** ……..gm. 5. 1 6 **** **** 1 **** ……..gm. 6. 2 9 **** **** 1 **** ……..gm. 7. 1 3 **** 1 **** **** ……..gm. 8. 1 3 **** 2 **** **** ……..gm. 9. 1 1 **** **** **** 1 ……..gm. 10 1 3 **** **** **** 2 ……..gm.
- 10. Experiment – 2 AIM: To study the setting of mixtures of cement with sand, lime and fly-ash with respect to time and strength. Requirements: Beakers, glass rod, weights, small wooden boxes or empty match boxes. Lime, pit sand, river sand, cement, fly-ash, rice husk.
- 11. Procedure:- 1. Prepare mixtures of the various compositions as given in the following observation table. 2. Take each of the mixtures in different beakers and prepare their pastes by adding minimum quantity of water. 3. Take 9 empty match-box inner cases and mark them from 1 to 9. 4. Fill three cases with paste of each composition. 5. Spray water from time to time over the pastes so that they remain moist all the time. 6. After three days take out one slab of each composition and test for their strength by the method described in previous experiment. 7. Similarly, take out a set of three slabs after 7 days and then after 30 days and test for their strengths.
- 12. Observations:- Note: - The slab should be of 0.5 cm thickness, 2 cm wide and 10 cm long. Conclusion: -The strength of the slab increases with increase in the setting time allowed…! S.No Composition of mixture Minimum weight require to break the slab after 3 days 10 days 20days Cement : River sand ……..gm ……..gm ……..gm 1:03 Cement: River sand: Fly- ash ……..gm ……..gm ……..gm 2:09:01 Cement: River sand: Lime ……..gm ……..gm ……..gm 1:03:01
- 13. Bibliography:- 1. PRACTICAL MANUAL 2. www.wikkipidia.com 3. www.icbse.com 4. www.slideshare.com