Perlite
Perlite is sodium potassium aluminosilicate, it is a naturally occurring mineral, and therefore non-renewable. It a dark grey type of volcanic glass which formed when volcanic obsidian glass is saturated in water over a long period.
In its natural raw state it has a density of around 1100 kg/m3 and solid, it is generally more commonly known in its expanded or processed state. When heated to temperatures of up to 980-C it softens and the entrapped water is released as steam which causes particles in their plastic state to expand up to 20 times their original size.
The expanded form of perlite has a density of between 30–150 kg/m3, a neutral pH level, efficient at absorbing small amounts of water, and draining water as it is spherical and with some insulating qualities due to its inherent air gaps.
It has been used in agriculture for many centuries, partly because the volcanic areas where it is found are also fertile soils. Today it is used in common gardening, hydroponics and in construction as a lightweight aggregate in concrete, as filling material, acoustic or insulation application and in fireproofing.
The global reserves of perlite are estimated to be around 700 million tonnes, with around 500,00 tonnes produced each year primarily from Greece, the US, Turkey, and Japan. Vermiculite is a very similar material to perlite with similar uses but some slightly different characteristics.
[edit] Related articles on Designing Buildings
- Composites.
- Deleterious materials in construction.
- Insulating plaster.
- Materials.
- Metal in construction.
- Phase change materials..
- Sustainable materials for construction.
- Types of biobased materials.
- Types of materials.
- Use of ceramics in construction.
- Vermiculite.
[edit] External links
Featured articles and news
Investors in People: CIOB achieves gold
Reflecting a commitment to employees and members.
Scratching beneath the surface; a guide to selection.
ECA 2024 Apprentice of the Year Award
Entries open for submission until May 31.
UK gov apprenticeship funding from April 2024
Brief summary the policy paper updated in March.
For the World Autism Awareness Month of April.
70+ experts appointed to public sector fire safety framework
The Fire Safety (FS2) Framework from LHC Procurement.
Project and programme management codes of practice
CIOB publications for built environment professionals.
The ECA Industry Awards 2024 now open !
Recognising the best in the electrotechnical industry.
Sustainable development concepts decade by decade.
The regenerative structural engineer
A call for design that will repair the natural world.
Buildings that mimic the restorative aspects found in nature.
CIAT publishes Principal Designer Competency Framework
For those considering applying for registration as a PD.
BSRIA Building Reg's guidance: The second staircase
An overview focusing on aspects which most affect the building services industry.
Design codes and pattern books
Harmonious proportions and golden sections.
Introducing or next Guest Editor Arun Baybars
Practising architect and design panel review member.
Quick summary by size, shape, test, material, use or bonding..