シャドーイング練習: MinuteCement - LC3 - 動画で英語スピーキングを学ぶ
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In 2012, 3 .6 billion tons of cement were produced worldwide.
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That amount is more than all the food produced for human consumption that same year.
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We mixed most of the cement with about 22 billion tons of aggregates and 2 .5 billion tons of water.
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This makes concrete the product most consumed by humans.
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We use it to build homes, bridges and other infrastructure we use every day.
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The reasons concrete is so popular is because it is cheap, made of widely available materials and easy to use.
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But the global demand for concrete requires huge amounts of resources.
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And we are going to need even more.
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By 2050, the cement consumption is expected to double.
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Look at how China alone is already consuming more cement than the whole world in 1990, and how India's cement production has doubled over the past 10 years.
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It will be a real challenge to meet the projected demand.
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Compared to many other materials, producing cement is very ecological.
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But with several brilliant tons produced each year, the cement industry is a major contributor to global CO2 emissions.
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Where does it come from exactly?
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To manufacture cement, limestone and clay are heated together in a large kiln at about 1450 degrees Celsius.
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This produces an intermediate material called clinker, which is rapidly cooled, mixed together with gypsum and ground to make cement.
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40 % of CO2 emissions come from burning the fuels needed for the kiln.
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The efficiency of this manufacturing process is already optimized in most modern cement plants.
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But we can act on the 60 remaining percent of CO2 emissions, which come straight from the decomposition of the limestone.
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How, you ask?
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We can substitute part of this clinker by less CO2 -intensive materials, called supplementary cementitious materials.
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We often throw in waste materials from other industries.
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For example, blast furnace slag from steel plants or fly ashes from coal -fired power plants.
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What you get is a blended cement.
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Sadly, there are not enough substitute materials for everyone.
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So what other substitutes can we use?
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When calcined at a temperature of only 800 degrees Celsius, clay becomes reactive and can be used as a replacement material.
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We can also add limestone without any heating.
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Simply grind it and voila!
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We know how to use them separately, but if we add both of them to clinker, there is a synergy between the components and you get a perfectly good cement even with high additions.
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This is where LC3 comes in.
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LC3 stands for Limestone Calcined Clay Cement.
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It is a special blend composed of 50 % clinker, 30 % calcined clay and 15 % ground limestone.
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With 50 % of replacement, we can double the production of cement with the same amount of clinker better yet we can use limestone
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and clay of lower grade normally discarded by industries no precious agricultural soil
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or topsoil will be used also clays are abundantly available in
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regions where the highest cement consumption is expected LC3 aims to
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provide local solutions to the global demand this new material is
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very attractive is it sure it is low carbon up to
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50 % of the clinker can be substituted the limestone doesn't need to be heated
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and the clay is activated at low temperature.
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It is low cost.
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Cheap, low -grade materials can be used.
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Limestone and clay are widely available from existing quarries and easily extracted, within the first 5 meters of the earth's crust.
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It is low capital.
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Increasing production with LC3 requires less investment than adding a new production line.
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Simply adapt an existing kiln or buy a cheap one for the clay.
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And the best part is, LC3 is easy to use.
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You can replace a normal cement bag by a LC3 bag.
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You get the same handling, same procedure.
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Before LC3 can be mass produced, it needs to be certified according to industry standards.
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This is why LC3 has become a large -scale project, with scientific partners in Switzerland,
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India and Cuba, many industrial partners around the globe and the support of the SDC.
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Given the great advantages of LC3, we have the full support from the industry to show it's easy handling, its easy casting, its strength and its durability.
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As a group, we are all working full speed to make cement more sustainable.
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And as always, thanks for watching!
この動画で鍛えるスピーキング目標
この動画は、科学的な説明や技術用語を含む議論をスムーズに理解し、再現する能力を養うのに最適です。特に、shadow speech(シャドーイング)を通じて長文の構造や論理的な流れを把握し、IELTS スピーキング対策にも役立つ説明能力を向上させることが目標です。
フレーズバンク:使い回せる表現
- 「This makes ~ the product most consumed by humans」(これにより~は人間が最も消費する製品となる)
- 「The reasons ~ is because ~」(~の理由は~であるから)
- 「Compared to many other materials, ~」(他の多くの材料と比べて~)
- 「What you get is a perfectly good ~」(得られるのは完璧に優れた~である)
- 「The best part is: ~」(最も良い点は~である)
弱点を克服!発音とリズムのポイント
この動画を使って英語の発音を良くするには、特に「clinker」「calcined」「supplementary」などの技術用語の発音に注意しましょう。また、長文の中でのポーズの位置やストレスの置き方が重要です。shadow speakの練習時には、ネイティブスピーカーのリズムに合わせて声を出し、「But we can act on the 60 remaining percent...」のような接続詞から始まる文の流れを覚えましょう。動画で英語学習することで、自然な発音とスピーキングの流れを身につけることができます。
シャドーイングとは?英語上達に効果的な理由
シャドーイング(Shadowing)は、もともとプロの通訳者養成プログラムで開発された言語学習法で、多言語習得者として知られるDr. Alexander Arguelles によって広く普及されました。方法はシンプルですが非常に効果的:ネイティブスピーカーの英語を聞きながら、1〜2秒の遅延で声に出してすぐに繰り返す——まるで「影(shadow)」のように話者を追いかけます。文法ドリルや受動的なリスニングと異なり、シャドーイングは脳と口の筋肉が同時にリアルタイムで英語を処理・再現することを強制します。研究により、発音精度、抑揚、リズム、連音、リスニング力、そして会話の流暢さが大幅に向上することが確認されています。IELTSスピーキング対策や自然な英語コミュニケーションを目指す方に特におすすめです。