Parameters
considered in selection of a good construction stone
Stone is widely use in the construction. There are some
considerations needed to be considered in the selection of a suitable
construction stone which are related with the cost, hardness, durability and appearance.
There some standards for the choosing of stones for construction to determine
the properties of a stone. The norms are based upon the following parameters
below.
- Chemical composition of stone:
- Strongness and hardness:
- Durability:
- Resistance to fire:
- Bio-Deterioration:
- Appearance:
1.
Chemical composition of stones:
The chemical properties of a stone toward a chemical influence are
one of an important criterion to determine the suitability of a stone for any
construction material selection. Different stone has their different elements
and compounds thus this also will give a different properties. Therefore, the
stone must be tested and verified in order to determine the chemical properties
and composition of a stone. For example, Magnesium mix in the limestone will
change the structural arrangement of the limestone and made it to be stronger and
the mixture is called Dolomite. The stones weathering resistant ability can be
improve by mix it with silicates as cementing materials.
2.
Strongness and hardness:
The strongness and hardness of a stone is related with its load
bearing capability. The stronger the stone are usually heavier and more compact
grained. The good stone have a density of above 2.7. There are some factor
affecting strength, hardness and toughness of a stone:
Factors affecting
strength, hardness and toughness
- Hardness or softness of the
components
- Proportions of the hard and
soft minerals
- Size and shape of the minerals
- Cohesion
- Porosity
- Density
- Cementing material
a) Hardness or softness of the components:
The hardness or softness of a stone is associated with the
component of stone. For instance, Stones containing Silicate, Sodium, and
Potassium are poor and consider as a soft-stone. The stones containing
Magnesium, Calcium, and Iron are good and consider as a hard-stone.
b) Proportion of hard and soft materials:
The proportion of hard and soft materials of a stone affect is
strength and load bearing capability. The higher amount of hard material will
result with a harder and a more weathering resistance stone.
c) Size and shape of the minerals is stones:
The stronger stone has a fine crystal and vice versa, this
property example the pore of a stone is associated with the fineness of the
stone. Crystalline solids are more superior then the non-crystalline solids
because there are harder and compacter.
d) Cohesion:
This criterion is about the property of the
strength or attraction of the atoms or particles to attract each other. In
general, the fine grains have more cohesive power than the coarser grains. The
hardness, strength, and toughness of a stone is increase with the force of
attraction of the atoms or particles. In other words, a stone have the higher
the cohesive force the greater the hardness, strength and toughness of the
stone is. The property of compactness also depends extremely on cohesion.
e) Porosity:
Porosity is the percentage of the pores contained in a substance. The
porosity affects the load bearing capability of a stone. That has been known
that the Porosity can reduce the strength up to 30 – 40. It also influence the
resistance of a stone to resist a concentrated (point) load.
f) Density:
The denser the stone the greater strength of the stone is. One can
made a stone denser by compacted it so that it would also be non-porous and
strong, hence the toughness also depends upon the density.
g) Cementing material:
The cementing material is one of the
factors of the stone selection. For example, the Stones with silicates as
cementing material will have a better weathering resistance than those with
calcareous or ferruginous binding material.
3) Durability:
The building designer has to consider the long lasting properties
of the stone material used. To make sure the stability of the building
structural system is safe.
4) Resistance to heat:
The
higher the heat resistance of a stone the lower the coefficient of expansion;
this reduces the risk of thermal stress.
5) Bio-deterioration:
Some
special of the microbes can grow on the surface and in small splits, this would
cause peel off and affect the quality of the stone. Therefore, the stone use
need to undergo treatments to prevent the problem.
6) Appearance:
Factors
to be considered in stone construction
A builder need to
consider some factor such as the properties of the stones, type of construction
,treatment or maintenance needed, cost , availability, rule and regulation and
appearance.
1. One
has to know about the properties of a stone used like the hardness, strength
and understand the advantages, disadvantages and limitation of the material. To
ensure the material used is match with the standard requirement.
2. Type of the construction at related with the
building system such as roofing system, flooring, wall and so on. For example,
the limestone has a good strength and
weathering characteristics. Limestone is usually used in the production of
cladding, flooring, ashlar and other forms of walling.
3. A treatment should be done to improve the quality or the building materials used.
Maintenance should be performed frequently to ensure the well-functioning of
the component.
4. Cost and the
availability of the material use. The builder need to think about the budget,
and the availability of the material (is it easy to obtain, transportation and
so on)
5. The rule and the regulation in the building construction. Such as thickness,
density, porosity and the type of the stone use for certain construction
work.
6. Chose the colour and pattern of the stone which is match and suit with the
design of the building to have a nice outlook.
The video below shows the natural stone veneer grouting.
The video below shows the providence farm stonework.
good job~well done^^~V
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ReplyDeletewakaka...^^~V