Explain natural vs. artificial materials, timber vs. reinforced concrete, and characteristics of good construction timber and igneous rocks.

Here are the answers to Question 1:

a)
Natural materials are those found in nature and used in construction with minimal processing. Artificial materials are manufactured by humans through chemical or industrial processes.

• Natural material example: Timber
• Artificial material example: Steel

b)
Four advantages of timber over reinforced concrete:

• Timber is generally lighter than reinforced concrete, reducing foundation loads.
• Timber provides better thermal insulation properties compared to concrete.
• Timber is a renewable resource, making it more sustainable.
• Timber is often easier to work with and shape on-site, allowing for faster construction.

c)
Four characteristics of good construction timber:

• Durability: Resistance to decay, insects, and fungi.
• Strength: High strength-to-weight ratio to withstand loads.
• Workability: Easy to cut, shape, and fasten without splitting.
• Dimensional Stability: Minimal warping, shrinking, or swelling with changes in moisture content.

d)
An igneous rock is formed from the cooling and solidification of molten rock (magma or lava).
The two main classes of igneous rocks are differentiated by their process of formation:

• Intrusive (Plutonic) Igneous Rocks: Form when magma cools slowly beneath the Earth's surface. This slow cooling allows for the formation of large, visible mineral crystals. An example is granite.
• Extrusive (Volcanic) Igneous Rocks: Form when lava cools rapidly on or near the Earth's surface. The rapid cooling prevents large crystal growth, resulting in fine-grained or glassy textures. An example is basalt.

e)
Four wood preservatives/protective products:

• Creosote
• Copper Naphthenate
• Borates
• Chromated Copper Arsenate (CCA)