How many QCAA Engineering questions cover Civil engineering materials?

AusGrader has 8 QCAA Engineering questions on Civil engineering materials, all with instant AI grading and detailed marking feedback.

QCAA (QCE) Engineering — Civil engineering materials Questions & Answers | AusGrader

Analyse the information in the table to determine whether polyvinyl chloride (PVC) or polyethylene is the most suitable material for wastewater pipes in the home. Justify your response with four properties from the table.

Properties	PVC	Polyethylene
Mechanical	resistant to abrasion, impact and weathering rigid — limited flexibility, can withstand high pressure	resistant to cracking, impact and environmental stress; strong; durable malleable — highly flexible
Young’s modulus	2.41–4.14 GPa	1.08 GPa
Yield strength	40.7–44.8 MPa	26.2–33.1 MPa
Tensile strength	40.7–51.7 MPa	22.1–31.0 MPa
Chemical	excellent chemical resistance (including corrosive chemicals)	good chemical resistance
Thermal	good heat resistance	very good heat resistance
Manufacturing cost	low	high

PVC is resistant to corrosive chemicals, making it more suitable for use in wastewater pipes in the home where it is likely to come into contact with corrosive chemicals, such as bleach or drain cleaner.

Although polyethylene has greater heat resistance than PVC, the pipes won't be exposed to anything hotter than boiling water in the home so PVC will be good enough.

PVC has a higher Young's modulus than polyethylene, which means it will be more rigid/less flexible, making it suitable for long lengths of pipe under the sink, floor or ground.

PVC is cheaper than polyethylene as the manufacturing cost is lower.

The combination of these properties makes PVC a more suitable material for use in the home.

Marking Criteria

Descriptor	Marks
Describes that PVC has greater chemical resistance than polyethylene	1
Describes that polyethylene has better thermal properties so is more heat resistant than PVC, but this is not an important property for this application	1
Describes that PVC is more rigid or less flexible than polyethylene	1
Describes that PVC is cheaper than polyethylene	1
Determines that PVC would be most suitable for wastewater pipes in the home	1

QCAA Engineering Civil engineering materials

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