# Materials to take us beyond concrete: answers and explanations

Cambridge IELTS 18, Test 3, Reading Passage 1

Source: Passage, questions and answer key from Cambridge IELTS 18, Test 3, Reading Passage 1. © Cambridge University Press & Assessment. Used for educational practice. Explanations and evidence notes are written by Testmigo.

## Answer key

| Q | Answer | Proof |
| --- | --- | --- |
| 1 | G | Fly ash, a byproduct of coal-burning power plants ... Iron-ore slag, a byproduct of the iron-ore smelting process |
| 2 | D | Vancouver, Vienna and Brumunddal in Norway are all home to constructed tall, wooden buildings. |
| 3 | C | the ingredients of concrete relatively cheap and found in abundance in most places around the globe |
| 4 | F | only when a wider range of construction projects has been proven in practice will it be possible to see wood as a real alternative to concrete |
| 5 | architects | but climate change is driving architects to turn to treated timber as a possible resource. |
| 6 | moisture | Wood expands as it absorbs moisture from the air and is susceptible to pests |
| 7 | layers | An adhesive is used to stick layers of solid-sawn timber together |
| 8 | speed | Construction experts say that wooden buildings can be constructed at a greater speed than ones of concrete and steel and the process |
| 9 | C | the use of alternative materials might not make sense from an overall carbon reduction perspective |
| 10 | A | "Concrete is amazing stuff. Making anything with similar properties is going to be very difficult." |
| 11 | B | the company is seeing increasing demand globally for building in wood, with climate change concerns the key driver |
| 12 | D | these alternatives are rarely as cost-effective as conventional cement |
| 13 | A | But it is the scale on which it is used that makes it high carbon. |

## Why these answers are right

**1. G.** Section G explains where fly ash and slag come from: fly ash is a byproduct of coal-burning power plants and slag a byproduct of iron-ore smelting. Both are industrial processes, and both materials can replace some cement in concrete, so the answer is G.

**2. D.** Section D lists Vancouver, Vienna and Brumunddal in Norway as places that are home to tall wooden buildings. Those cities are the various locations, and tall matches high-rise, so the reference is in section D.

**3. C.** Section C says the ingredients of concrete are relatively cheap and found in abundance in most places around the globe. "How widely available" is a paraphrase of found in abundance almost everywhere, so section C is correct.

The why and the trap for questions 4 onwards are free with an account on the [answers page](https://testmigo.com/ielts/reading/materials-to-take-us-beyond-concrete/answers).

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