Building stones are fundamental materials in construction, providing
structural integrity and aesthetic appeal. Understanding the properties of good
building stones and the quarrying process is crucial for ensuring the longevity
and durability of structures. This guide delves into the essential
characteristics of quality building stones, the methods of stone quarrying, and
the factors contributing to stone deterioration.
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| Properties and Quarrying of Good Building Stones |
Properties of Good Building Stones
- Appearance
- Good and
uniform color. - Dark-colored
stones are more susceptible to weathering. - Crushing
Strength - Minimum 100
MPa. - Durability
- High
durability is essential. - Hardness
- If the
hardness coefficient is less than 14, the stone is not suitable for
roadwork. - Minimum
hardness coefficient for roadwork is 17. - Wear
- Wear by
Attrition Test should be less than 3%. - Resistance to
Fire - Stones should
have good resistance to fire. - Specific
Gravity - Should be
greater than 2.7. - Water
Absorption - Should be less
than 0.6%. - Texture
- Should be free
from cracks and cavities. - Toughness Index
- Determined by
Impact Test. - High
toughness: >19 - Moderate
toughness: 13-19 - Not tough:
<13 - Weathering
Resistance - Stones should
be sufficiently resistant to weathering. - Should be
well-seasoned and facilitate dressing.
Stone Quarrying Process
- Hand Tools
- Basic method
for small-scale extraction. - Channeling
Machine - Operated by
steam or electricity. - Blasting
- Most commonly
used method for large-scale production.
Dressing of Stones
Purpose:
- To increase
strength and durability. - To obtain a
desirable appearance. - To ease
transportation and handling. - To suit the
requirements of stone masonry.
Deterioration of Stones
- Alternate
Drying and Wetting - Frost Action
- Movement of
Water/Chemicals - Vegetation or
Organic Growth
Frequently Asked Questions
- What is the
minimum crushing strength required for a good building stone? - The minimum
crushing strength required is 100 MPa. - Why is the
hardness coefficient important for building stones? - The hardness
coefficient determines the stone’s suitability for roadwork. Stones with
a hardness coefficient less than 14 are not suitable for roadwork. - What is the
acceptable water absorption rate for building stones? - The water
absorption rate should be less than 0.6%. - How is the
toughness index of a stone determined? - The toughness
index is determined by the Impact Test. Stones with a toughness index
greater than 19 are considered highly tough. - What are the
common methods of stone quarrying? - Common methods
include using hand tools, channeling machines, and blasting.
Conclusion
Selecting the right building stone is crucial for the durability and
aesthetic appeal of any construction project. By understanding the properties
of good building stones and the quarrying process, you can ensure the longevity
and strength of your structures. Keep in mind the factors that contribute to
stone deterioration and take preventive measures to maintain the integrity of
your building materials.
