classes of lime, their uses, tests on lime

1. LIME
BY
RIMPI BARO
LECTURER, CIVIL ENGINEERING DEPARTMENT
PANDIT DEENDAYAL PETROLEUM UNIVERSITY,
GANDHINAGAR
BUILDING MATERIALS AND CONSTRUCTION

2. Lime

3. • To convert the raw material into lime, heating to
temperatures between 800 deg C - 1000 deg C is required. At
these temperatures the limestone breaks down by giving off
carbon dioxide leaving calcium oxide which is known as
quicklime.
• Quicklime is unstable and reacts, often very rapidly, with
water to form calcium hydroxide. This process produces heat
and is known as hydration. When exposed to the atmosphere
this calcium hydroxide can react again by absorbing carbon
dioxide from the atmosphere to once again become calcium
carbonate.
• This is known as the lime cycle and is shown in the diagram b.
It is calcium hydroxide which, when mixed with sand to make
a mortar, builders have used over the millennia. The setting
process is the re-absorption of carbon dioxide from the
atmosphere called carbonation.

5. Lime: the cycle

6. Classification of Lime: IS712-1973

7. Lime Kiln

8. Old lime kiln

9. Old lime kiln

10. Why use lime

11. Why use lime

12. Why use lime

14. Constituents in limestone

17. Properties of Lime

18. CLASSIFICATION OF LIME
• FAT LIME
• HYDRAULIC LIME
• POOR LIME

19. FAT LIME

21. Non-hydraulic lime

24. HYDRAULIC LIME

26. Hydraulic lime

27. POOR LIME

28. Composition of various forms of limes
Variety of Lime CaO
( %)
MgO
(%)
Al2O3
(%)
SiO2 Fe2O3 Others
Fat lime or High
Calcium Lime
Over 95 1-2 Trace 2-3 Trace Trace
Hydraulic Lime 40-60 30-40 Below 5 Upto
30
Below 3 Upto 5

29. MANUFACTURE OF LIME
• Collection of raw materials
• Burning of limestone: Clamp burning,
Intermittent kiln burning, Continuous kiln
burning
• Slaking of burnt lime

30. Collection of raw materials
• For manufacturing fat lime, content of
impurities < 5 %
• Kankar lime may be used for manufacturing
hydraulic lime
• Limestones may be collected and slaked near
the manufacturing site
• Fuels: coal, wood, coke, cinder etc.

32. CLAMP BURNING

33. CLAMP BURNING

34. INTERMITTENT FLARE KILN

35. INTERMITTENT FLARE KILN

36. CONTINUOUS LIME KILN

37. CONTINUOUS LIME KILN

38. PRECAUTIONS
• Lime easily affects skin; avoided by coating
skin with oil
• Health hazard if breathed in
• Slaking of lime is exothermic, use goggles,
gloves etc

39. Storage of lime
• Should be kept in air tight vessels or large
heaps under covered gunny bags
• Stored in weather proof sheds which are dry
• Lime should not be slaked less than 1 week
and not more than 3 weeks before its use

40. LABORATORY TESTING OF LIMESTONE (IS 6932:1973)
Physical and Chemical tests are conducted on limestone to determine their
suitability

41. Chemical tests: Heat test

42. Chemical tests: Acid test

43. Chemical tests: Slaking test

44. Field Testing of Building Lime (IS 1624-1974)

46. Lime mortar

47. Lime mortar

48. White washing

49. LIME FOR SOIL IMPROVEMENT AND SUBGRADE
STABILIZATION
• Wet, weak, fine grain soil can prove to be a major challenge at many
construction sites. Muddy site conditions make for difficult working
conditions. Access is difficult for construction vehicles. It’s difficult to
reach the soil moisture and compaction requirements established by the
project civil or geotechnical engineer. Wet, poorly compacted soil makes
for poor pavement support and embankment/fill.
• Lime quickly improves the soil condition during construction and can add
long term improvements to key soil properties. Adding lime can cause
three major soil improvements:
• Soil Drying – Reducing the soil moisture content
• Soil Modification – Reducing soil plasticity, aiding compaction and
increasing early strength
• Lime Stabilization – Increasing long term strength and reducing swell
potential
• As a general rule, authorities on soil stabilization recommend that lime be
considered for all soils when the plasticity index exceeds 10

50. Hydrated lime slurry in soil
stabilization

51. REFERENCES
• Building construction materials techniques, P.
Purushottam Raj
• Building Materials, S.K. Duggal
• Building Materials, B C Punmia
• www.civilconstructor.org