Lesson Notes By Weeks and Term v5 - Grade 10
Revision and examination preparation (Grade 10 Civil Technology) – Week 10 focus
Download the Lessonotes Mobile South Africa app for faster lesson access on Android and iPhone.
Revision and examination preparation (Grade 10 Civil Technology) – Week 10 focus
Download the Lessonotes Mobile South Africa app for faster lesson access on Android and iPhone.
Subject: Civil Technology
Class: Grade 10
Term: Term 4
Week: 10
Theme: General lesson support
This page supports the lesson note with a companion video and a short classroom-ready summary.
For class groups and homework, share this lesson page so learners also get the summary, objectives, and full lesson context.
This week is dedicated to consolidating your understanding of the Grade 10 Civil Technology syllabus in preparation for upcoming assessments. Civil technology is the backbone of our built environment. From the RDP houses ensuring safe and dignified living, to the bridges connecting our provinces, to the water pipelines delivering essential resources – civil technology principles are at play. Mastering this subject allows you to understand and potentially contribute to improving the infrastructure that directly impacts the quality of life in South Africa. We'll review key concepts, work through practice problems, and connect the theory to real-world applications.
2.1 Materials and Their Properties Concrete: Concrete is a composite material composed of cement, aggregates (sand and gravel), and water. The cement acts as a binder, holding the aggregates together as it hardens through a process called hydration.
Strength: Concrete's compressive strength is its ability to resist crushing forces. This is measured in MPa (Megapascals). Different concrete mixes have different strengths (e.g., 20 MPa, 30 MPa, etc.).
Durability: Concrete must withstand environmental factors like weathering, chemical attacks, and abrasion. Admixtures can be added to improve durability.
Workability: Workability refers to the ease with which concrete can be mixed, placed, and compacted. A good mix is neither too stiff nor too watery. Slump tests are used to measure workability.
SANS Standards: SANS (South African National Standards) provides guidelines for concrete mix design, testing, and quality control. These standards ensure safety and structural integrity.
Steel: Steel is an alloy of iron and carbon. It's used in construction primarily for its tensile strength (ability to resist pulling forces).
Reinforcement: Steel bars (rebar) are embedded in concrete to increase its tensile strength, creating reinforced concrete. This is crucial because concrete is weak in tension.
Grades: Steel is available in different grades, each with a specific yield strength (the stress at which it begins to deform permanently).
Corrosion: Steel is susceptible to corrosion (rust). Proper concrete cover (thickness of concrete surrounding the steel) is essential to protect it. Epoxy coatings can also be used.
Timber: Timber is a natural building material sourced from trees. It's renewable and relatively lightweight.
Strength: Timber's strength depends on the species, grade, and moisture content.
Durability: Timber is vulnerable to decay and insect attack. Preservatives are used to extend its lifespan.
SANS 10082: This SANS standard deals with the preservative treatment of timber.
Bricks: Bricks are manufactured from clay, shale, or concrete and fired in a kiln.
Strength: Brick strength is determined by its crushing strength.
Durability: Bricks should be resistant to weathering and frost damage.
Types: Common types include clay bricks, concrete bricks, and face bricks.
Bonding: Bricks are laid in various patterns (bonds) to create strong and stable walls. Common bonds include stretcher bond, English bond, and Flemish bond. 2.2 Quantity Surveying Basics Estimating Material Quantities: Accurate material estimation is crucial for project budgeting and cost control.
Example 1: Brick Wall: Calculate the number of bricks needed for a wall 5m long, 2.5m high, and one brick thick (220mm). Assume a standard brick size of 220mm x 110mm x 75mm and a mortar joint of 10mm.
Step 1: Calculate the number of bricks per meter length: With a 10mm mortar joint, each brick occupies 220mm + 10mm = 230mm = 0.23m in length.
Step 2: Number of bricks per course (row): 5m / 0.23m/brick = 21.74 bricks. Round up to 22 bricks per course.
Step 3: Calculate the number of courses per meter height: With a 10mm mortar joint, each brick occupies 110mm + 10mm = 120mm = 0.12m in height.
Step 4: Number of courses: 2.5m / 0.12m/course = 20.83 courses. Round up to 21 courses.
Step 5: Total number of bricks: 22 bricks/course 21 courses = 462 bricks.
Allowance for Wastage: Add 5-10% for wastage: 462 0.05 = 23.
1. Add 24 bricks for wastage.
Total Bricks Required: 462 + 24 = 486 bricks.
Example 2: Concrete Slab: Calculate the volume of concrete needed for a slab 6m long, 4m wide, and 150mm (0.15m) thick.
Step 1: Volume = Length x Width x Thickness Step 2: Volume = 6m x 4m x 0.15m = 3.6 cubic meters (m³)
Allowance for Wastage: Add 5-10% for wastage: 3.6 0.05 = 0.
1
8. Add 0.2 m³ for wastage.
Total Concrete Required: 3.6 + 0.2 = 3.8 m³ 2.3 Structural Mechanics: Loads and Stability Loads: A load is a force acting on a structure.
Dead Load: The weight of the structure itself (e.g., walls, roof, floors).
Live Load: Variable loads due to occupancy and use (e.g., people, furniture, snow).
Wind Load: The force exerted by wind on a structure.
Stability: A structure must be stable to resist overturning, sliding, and collapse under load. Proper foundations and structural connections are crucial for stability. The location and strength of materials also affect the stability of the structure.
South African Context: Buildings in coastal regions (e.g., Durban, Cape Town) need to be designed to withstand high wind loads. Seismic activity in certain areas (e.g., Western Cape) requires earthquake-resistant design. 2.4 Tools and Equipment Hand Tools: Hammers, saws, trowels, levels, measuring tapes, screwdrivers, pliers.
Power Tools: Drills, grinders, concrete mixers, vibrators.
Safety: Always wear appropriate personal protective equipment (PPE) when using tools and equipment (e.g., safety glasses, gloves, hard hats). Follow manufacturer's instructions and safety guidelines.