943512
| Question | Answer |
| Where are some raw materials that are used to make construction materials found? | Some raw materials used to make construction materials are found in the Earth's crust. |
| How can than the hardness of two materials be compared? | Hardness can be compared by rubbing to materials together. |
| Fill the gaps: ....... is harder than ......, and marble is ...... than .......... | Granite is harder than marble, and marble is harder than limestone. |
| Many buildings look like they are made from one material, but what are they often made of? | Many buildings look like they are made from one material, but they are often made with different materials and only lined with an expensive material. |
| What is limestone? | Limestone is a sedimentary rock. |
| What is limestone made of? | It is made of soft sediments compressed and cemented together. This makes limestone quite soft. |
| What is marble? | Marble is a metamorphic rock. |
| When is marble formed? | Marble is a metamorphic rock formed when limestone is changed by heat and pressure, and is typically composed of an interlocking mosaic of carbonate crystals. |
| Why is marble harder than limestone? | Marble is harder than limestone because it has been baked. |
| When is granite formed? | Granite is formed when magma cools and solidifies. |
| What is granite? | Granite is an igneous rock with interlocking crystals. |
| Is granite very hard or soft? | This makes granite very hard. |
| What is thermal decomposition? | Thermal decomposition is a reaction where one substance breaks down on heating to give at least two new substances. |
| Calcium carbonate (limestone) thermally decomposes when heated. Give the word and symbol equation for the thermal decomposition of calcium carbonate. | calcium carbonate → calcium oxide + carbon dioxide CaCO3 → CaO + CO2 |
| When is cement made? | Cement is made when limestone is heated with clay. |
| When is concrete made? | Concrete is made by mixing cement, sand and small stones with water. |
| What is reinforced concrete? | Reinforced concrete is a composite material which has steel rods or meshes running through it. |
| What do composites contain? | Composites contain at least two materials that can still be distinguished. |
| Fill the gaps: Concrete is strong under ........... (squashing force) but weak under ....... (pulling force). | Concrete is strong under compression (squashing force) but weak under tension (pulling force). |
| If heavy loads are applied to a beam what happens? | If heavy loads are applied to a beam, the concrete will bend. |
| What does this create? | This creates tension and compression. |
| What does the tension do to the concrete? | The tension cracks the concrete. |
| Why is reinforced concrete a better construction material? | Reinforced concrete is harder and more flexible than concrete, so is a better construction material. |
| What do the steel rods in reinforced concrete do when the concrete is carrying a heavy load? | Steel rods stop concrete from stretching and cracking when it is carrying a heavy load. |
Want to create your own Flashcards for free with GoConqr? Learn more.