ENG10002 Tute12 - Ceramics and Concrete

Glasses are...

• Crystalline materials

• Amorphous materials

• Semi-crystalline materials

• Can be any of these structures

Which test is used to measure fracture toughness of materials?

• Tensile test

• Impact test

• 3-point bending test

• 4-point bending test

Concrete is mixed with more water than is necessary for hydration:

• To improve concrete mechanical properties

• To cut the cost of concrete

• To give concrete sufficient workability

• To increase concrete durability

An estimate of the tensile strength of concrete is determined by:

• Tensile testing

• Compressive testing

• Impact testing

• Four-point bend testing

Which concrete test method is not standardised?

• Compression

• Tension

• Flexural

• All of the above

Glass is considered as:

• Amorphous plastic

• Semi-crystalline plastic

• Crystalline ceramic

• Amorphous ceramic

Thermal toughening of glass is achieved by:

• Changing the chemical composition of glass

• Creating tensile stress in the surface of the glass

• Creating compressive stress in the surface of the glass

• Heating surface defects

An amorphous ceramic is heated just above the glass transition temperature. This transition causes it to become a:

• Glass

• Supercooled liquid

• Crystalline solid

• Liquid

Which material has the highest fracture toughness?

• Concrete

• Polypropylene

• Steel

• Pyrex glass

Diamond has a far higher yield strength than copper wire because:

• Covalent bonds in diamond cause dislocations to be immobile

• Diamond is highly perfect so it does not contain a significant number of dislocations

• Diamond can be considered a ceramic material

• Copper wire is usually annealed