Hiển thị các bài đăng có nhãn Topic Concrete. Hiển thị tất cả bài đăng
Hiển thị các bài đăng có nhãn Topic Concrete. Hiển thị tất cả bài đăng

Thứ Ba, 30 tháng 1, 2024

Reading practice - Matching names 3

 

Concrete alternatives

The push for innovation in the construction industry, driven by concerns about the environmental impact of traditional concrete, is gaining momentum. Concrete, a fundamental building material, contributes significantly to global warming, generating 8% of annual carbon dioxide emissions. Scientists, the U.S. government, and the concrete industry are actively seeking alternatives to address these environmental issues.

Mija Hubler, co-director of the Center for Infrastructure, Energy, and Space Testing at the University of Colorado, notes a surge in innovation over the past five years. The government's focus on environmental changes, such as rising sea levels, has spurred this movement, along with growing interest from home builders. Engineers are particularly enthusiastic about catering to home builders, as it aligns with their passion.

Hubler is working on a groundbreaking project to develop self-healing concrete, designed to repair existing structures without the need for demolition. Other concrete innovations and alternatives are also expected to emerge in the market in the next year or two, following current demonstration projects.

Key reasons for considering concrete alternatives include the carbon-intensive nature of cement, the primary component of concrete, which involves super-heating limestone using fossil fuels. The resulting carbon dioxide emissions, combined with the environmental impact of transporting heavy materials, contribute to the environmental concerns surrounding concrete.

Concrete alternatives address various issues, such as crack resistance, with some options offering better tensile strength. These alternatives can be molded like concrete but behave more like wood, allowing for unique architectural designs. Additionally, certain technologies draw inspiration from traditional earthen concepts like adobe, modernized for commercial viability. These alternatives provide improved temperature regulation, reducing the need for excessive energy consumption in heating and cooling.

Furthermore, according to Minagor Soras, a leading engineer at Aptos Construction, greener concrete alternatives alleviate environmental damage caused by quarrying limestone for cement, which disrupts landscapes and leads to dust pollution. Concrete production is also water-intensive, accounting for a significant portion of global industrial water use. The development of eco-friendly concrete alternatives aims to mitigate these environmental concerns while offering viable options for home building and improvement projects.

Hempcrete, made from hemp plant cores mixed with lime, sand, and water, is a lightweight and eco-friendly alternative to concrete. “While not suitable for foundations or load-bearing walls, it excels for interior walls, prefab panels, bricks, cinder blocks, and insulation”, notes Soras. With an insulation R-value of 2.4 to 4.8, it surpasses fiberglass batts. Hempcrete is carbon-negative, sequestering CO2 during plant growth and installation, and it uses less water than concrete. Prices vary but are generally higher than standard concrete.

Compressed Earth Blocks are modern alternatives to traditional methods, incorporating fibers, bamboo, or rebar for strength. “Environmentally conscious, they are unfired, lack lime, and often use locally sourced materials, potentially being cost-competitive with concrete”, says Novak Angler, the prosfessor of Construction at Havard University.

Green concretes like Ashcrete (using fly ash) and Fiber Cement (using wood pulp) replace energy-intensive materials. Ashcrete, reminiscent of ancient Roman practices, is strong, quick-curing, and cost-effective. Fiber cement, used in roofing and siding, resists cracking and warping.

“Ferrock, made from 95% recycled materials, is a carbon-negative concrete alternative up to five times stronger than regular concrete”, emphasizes Amstrong Green of AbitZ construction comany. It has better compressive strength and flexibility, suitable for various applications, including earthquake-prone regions. Availability is limited, but it's environmentally friendly.

Mycelium structures, grown from fungi fibers, offer a lightweight, versatile, fire, water, and mold-resistant material that is self-healing. While not widely available, it can be grown for walkways, driveways, and bricks. Biomass ingredients like fungi and bacteria are also used as binders in traditional cements.

Questions 1-4

Look at the following statements (Questions 1-4) and the list of people below.

Match each statement with the correct person, A, B, C or D.

Write the correct letter, A, B, C or D, in boxes 1-4 on your answer sheet.

NB   You may use any letter more than once.

1. This alternative works well with some tasks but cannot be used for others.

2. This kind of new alternatives may be cheaper than conventional concrete.

3. Creating new concrete alternatives increased during a certain period of time.

4. More sustainable substitutes to concrete limit ecological damage.

List of people

A. Novak Angler

B. Mija Hubler

C. Minagor Soras

Reading practice - Matching names 2

 

Concrete and its alternatives

Concrete, a fundamental component of contemporary construction practices, finds itself under intense scrutiny due to its adverse environmental impact. In the relentless pursuit of sustainable building materials, a cohort of dedicated scientists and industry experts has embarked on an exploration of inventive alternatives. This article endeavors to illuminate the discourse by presenting profound insights from five distinguished figures, each contributing a distinctive perspective to the ongoing quest for eco-friendly construction materials.

Alex Thompson, an esteemed engineering professor at Imperial College London, emphasizes the magnitude of global concrete usage. While acknowledging that concrete itself is not inherently high-carbon, Thompson accentuates the environmental repercussions stemming from its staggering volume in construction projects. "Concrete is not a high-carbon product. Cement is high carbon, but concrete is not. However, it is the sheer scale of its usage that renders it high carbon. The enormity of the manufacturing process is the crux of the issue," he expounds. Thompson passionately underscores the imperative for alternatives capable of matching concrete's efficiency on a grand scale.

Mia Johnson, the Vice President of Stora Enso, Europe's premier supplier of cross-laminated timber, delves into the escalating global demand for wooden construction. Johnson discerns that concerns about climate change are compelling architects to consider treated timber as a sustainable resource. "Wooden buildings can be erected at a greater speed than those made of concrete and steel, and the process is quieter," she points out. However, Johnson concedes that treated wood has its limitations, underscoring the need for proven success across a diverse array of construction projects to firmly establish it as a bona fide alternative to concrete.

Evan Miller, representing the UK’s Green Building Council, delves into alternatives such as fly ash and iron-ore slag. These waste products hold the promise of being incorporated into concrete mixes to curtail greenhouse gas emissions. Nevertheless, Miller cautiously remarks, "It's conceivable to replace the cement content in concrete with waste products to diminish the overall carbon impact, but a myriad of calculations must be considered throughout the entire life cycle of the building." He places significant emphasis on factoring in elements like transportation, as they could significantly influence the overall perspective on carbon reduction.

Taking a broader perspective, Olivia Walker and Liam Turner of the UK’s Royal Institute of International Affairs offer an encompassing view of innovation in the concrete industry. They highlight that while novel cements have been under discussion within the research community for over a decade, they face formidable challenges. "Presently, these alternatives are seldom as cost-effective as conventional cement, and they encounter raw-material shortages and resistance from customers," they conclude. This insightful observation brings to light the intricate complexities associated with introducing new materials into the construction industry and emphasizes the necessity of overcoming economic and market challenges.

Revisiting Alex Thompson's perspective, he accentuates the extraordinary properties of concrete, including its moldability and synergy with steel, rendering replication a formidable challenge. "Concrete is an extraordinary material. Producing anything with similar properties is bound to be exceedingly difficult," he asserts. Thompson underscores the vital role of innovation and human ingenuity in the development of alternatives capable of matching concrete's unparalleled versatility and strength.

Questions 1-5

Look at the following statements (Questions 9-13) and the list of people below.

Match each statement with the correct person, A, B, C or D.

Write the correct letter, A, B, C or D, in boxes 9-13 on your answer sheet.

NB   You may use any letter more than once.

1. Multiple calculations should be taken into consideration when other materials are used to replace cement.

2. Producing any material sharing comparable qualities with concrete will undoubtedly be very challenging.

3. Other alternative materials are often more expensive than traditional cement.

4. A component of concrete is high-carbon, not concrete itself.

5. Timber, which is treated, has its own weeknesses in construction practices.

List of People

A     Alex Thompson

B     Mia Johnson

C     Evan Miller

D     Olivia Walker and Liam Turner

 

Thứ Ba, 16 tháng 1, 2024

Reading practice - Matching names 1

 

Navigating Sustainable Construction: Unveiling Alternatives to Concrete

Concrete, an integral part of modern construction, is facing scrutiny due to its environmental impact. In the pursuit of sustainable building materials, scientists and industry experts are exploring innovative alternatives. This article presents insights from five key figures, each offering a unique perspective on the quest for eco-friendly construction materials.

Chris Cheeseman, an engineering professor at Imperial College London, underscores the global scale of concrete usage. While acknowledging that concrete itself is not inherently high-carbon, Cheeseman emphasizes the environmental impact due to its sheer volume in construction. "Concrete is not a high-carbon product. Cement is high carbon, but concrete is not. But it is the scale on which it is used that makes it high carbon. The sheer scale of manufacture is so huge; that is the issue," he says. Cheeseman stresses the necessity for alternatives that can match concrete's efficiency on a large scale.

Markus Mannstrom, Vice President of Stora Enso, Europe's leading supplier of cross-laminated timber, discusses the increasing global demand for wooden construction. Mannstrom notes that climate change concerns are driving architects to consider treated timber as a resource. "Wooden buildings can be constructed at a greater speed than concrete and steel, and the process is quieter," he highlights. However, Mannstrom acknowledges that treated wood has limitations and underscores the need for proven success in a variety of construction projects to establish it as a genuine alternative to concrete.

Anna Surgenor, representing the UK’s Green Building Council, delves into alternatives like fly ash and iron-ore slag. These waste products can be incorporated into concrete mixes to reduce greenhouse gas emissions. However, Surgenor cautions, "It's possible to replace the cement content in concrete with waste products to lower the overall carbon impact, but there are several calculations that need to be considered across the entire life cycle of the building." She emphasizes the importance of considering factors like transportation, as it could affect the overall carbon reduction perspective.

Felix Preston and Johanna Lehne of the UK’s Royal Institute of International Affairs offer an overarching view of innovation in the concrete industry. They note that while novel cements have been discussed for over a decade within the research community, they face challenges. "At present, these alternatives are rarely as cost-effective as conventional cement, and they face raw-material shortages and resistance from customers," they conclude. This insight highlights the complexities of introducing new materials into the construction industry and the need for overcoming economic and market challenges.

Returning to Chris Cheeseman, he highlights the remarkable properties of concrete, including its moldability and the synergy with steel, making it challenging to replicate. "Concrete is amazing stuff. Making anything with similar properties is going to be very difficult," he notes. Cheeseman underscores the necessity for innovation and human ingenuity to develop alternatives that can match concrete's versatility and strength.

Questions 6-13

Look at the following statements (Questions 9-13) and the list of people below.

Match each statement with the correct person, ABC or D.

Write the correct letter, ABC or D, in boxes 9-13 on your answer sheet.

NB   You may use any letter more than once.

 

1. Although it is not as high-carbon as cement due to its large manufacturing scale, concrete still has a significant level of carbon.

2. The poor response to the creation of new cements has been partially explained by high expense.

3. It would be challenging to develop a concrete substitute for construction that provides so many equivalent advantages.

4. Compared to concrete and steel, wooden houses can be built faster and more silently.

5. The significance of taking transportation into account because it may have an impact on the bigger picture on decreasing carbon emissions.

 

List of People

A     Chris Cheeseman

B     Markus Mannstrom

C     Anna Surgenor

D     Felix Preston and Johanna Lehne

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