What is the matrix phase and particle phase in concrete? Give any two properties of concrete.

Functions of matrix phase are as follows

1. To bind reinforcing particle / fibre strongly
2. It acts as medium for distribution of applied load to the dispersed phase.
3. It keeps the reinforcing fibre I proper orientation for the high strength development
4. It prevents propagation of cracks due to its plasticity

Functions of Dispersed phase are as follows

The dispersed phase comprises of fibres, normally with small diameter preferred to bulk ones. A special type of fibres widely known as Whiskers are used

Whiskers have following properties

1. They are very thin single crystals
2. They possess extremely large length / diameter ratios
3. They are flaw free
4. They are small in size, hence the degree of crystalline perfection obtained is high
5. They are exceptionally strong

All above properties make whiskers highly useful as reinforcing fibres as dispersed phase, but still these are not very commonly used due to following reasons

• They are very costly
• The process of incorporating them in matrix phase is tedious
• Examples of whiskers are oxides of aluminium, carbides ad nitrites of silicon, Graphite’s