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Good Morning Everybody!

Buenos Días a Todos!

Montserrat Martinez-Garcia

Do you remember the list of performance criteria applicable

to construction materials?

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Recap: Activity 1 “Performance Criteria”

1. Fit for the purpose2. Visual appearance3. Cost 4. Resistance to

degradation5. Ease of installation

or use

6. Environmental implication

7. Sustainability and recycling potential

8. COSHH considerations

9. Compatibility

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Recap: Activity 1 (Handout)

Task 1 (P6 and P8)• Identify the main performance criteria that you

would consider when specifying the following materials:

Facing Bricks.

Timber Post/Fencing.

Steel Cladding.

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Assignment clarification

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THE LEARNING OUTCOMES FOR TODAY’S SESSION

ARE HIDDEN BEHIND THIS PHOTOGRAPHS:

Be able to know the techniques used to produce these construction materials.

Be able to identify the main features and relevant properties of such materials.

How much do you know about these materials?

1. In pairs, research your assigned material to establish its method of production and manufacture (10 minutes).2. Produce a small presentation for the rest of the class (5+5 minutes). (Poster or verbal explanation?)

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Activity 2 “Research”

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Understanding construction materials: Their most important

features and properties (Task 1- P8)

FEATURES & PROPERTIES Concrete Steel Timber Bricks Gypsum

plaster Lime BESTOVERALL

STRENGTH

ELASTICITY

POROSITY AND WATER ABSORTION

THERMAL AND MOISTURE MOVEMENTELECTRICAL

CONDUCTIVITY/RESISTIVITY

THERMAL TRANSMITTANCE

(U VALUES)

DURABILITY

WORKABILITY

DENSITY

SPECIFIC HEAT CAPCITY

VISCOSITY

Rating each material as good, bad or average

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Features & Properties STRENGTHis the amount of stress, tension or weight that a material can endure before it starts to deform.

ELASTICITYis the amount of stress that a material can take before its elastic limit is reached and the material permanently distorts causing dimensional change.

POROSITYRefers to the number of pores that are present within a material. It is linked to the density (air entraining agent-concrete block example).

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THERMAL AND MOISTURE MOVEMENTAll materials expand with heat and contract with cold, so thermal movements must be taken into account when designing buildings.

THERMAL AND ELECTRICAL CONDUCTIVITY/RESISTIVITYBoth are closely linked. E. resistivity is the ability to restrict the passage of heat and electricity

THERMAL TRANSMITTANCE (U-VALUES)U-values are a measure of how thermally efficient a material is to the passage of heat.

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Features & Properties DURABILITYis the material resistance to surface scratching or abrasion.

WORKABILITYis the ease with which a material can be poured or placed into a formwork and finished.

DENSITYis how heavy something is for the volume it occupies.

The unit of density: Kg/m3

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SPECIFIC HEAT CAPACITYis related to the thermal capacity which is a measure of how much of a material can store heat energy.

VISCOSITY is also know as thickness, is the resistance of a liquid or substance to flow. Viscosity is related to workability.

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• Concrete has great compression strength but very weak tension strength and will require reinforcing with steel bars to prevent its failure by cracking.

• Timber is strong parallel to the grain but is weak perpendicular and it can be split easily.

• Steelwork copes very well with tension, compression and shear, however it will be weak in a fire. It buckle and fail if it is not fire protected.

• Brickwork and blockwork are strong on compression but it can be pushed laterally and rely on the mortar.

• Glass requires from another support to help it to resist.

STRENGTH

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STRENGTH EXAMPLE

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THE VERSATILITY OF REINFORCED CONCRETE

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THE VERSATILITY OF REINFORCED CONCRETE

Whole class discussion about the elasticity of:

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Activity 3 “Elasticity”

Plastic Steelwork

Concrete

Glass

We have two concrete blocks with the same volume: 1. What block has more pores or air pockets? 2. Which one has more density? 3. Can you say something about “air entraining agent”?

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Activity 4 “Porosity and Density”

Using the list of common construction materials and the features & properties table, name one material and its main feature that best describes it.

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Activity 5 “Consolidation”

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WORKABILITY (SLUMP TEST )

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FIRE RESISTANCE

For our next session: Check the main features &

properties of more materials.

We will need to understand the techniques used to prevent materials from

deterioration.

Any Questions?

Please your feedback is important!

- Put your right arm up if you have understood the whole class.

- Put your left arm up if you have only understood part of the class.

- Just scratch your head if you know ‘Nowt’ (Nothing).

Thank you for listening!