Sesc Pompeia / Lina Bo Bardi. Image Fernando Pires

混凝土的环境本钱

The 狂战狼穴Environmental Cost of Cement, and What to Do About It

几千年来,混凝土一直是修建环境的重要根底,一起也是全球运用最为广泛的人工资料。可是,无论是修建师仍是群众,都益发开端重视气候变化的影响与其成因,那么混凝土关于环境负面影响就现已不是一个小问题了。

Lucy Rodgers为BBC News写了一篇深入的文章,其间提到,在全球二氧化碳排放量总数里,来历于混凝土的二氧化碳大约为8%。这篇文章的布景是于波兰举行的联合国气候变化大会(COP24),为了满足于2015年拟定的《巴黎气候协议黑芝麻的成效与效果,碳排放量超高的混凝土,还有救吗?,千禧》,在2030年,混凝土的碳排放量有必要下降16%。

“假如混凝土工业是一个国家,那么它会成为国际第三大排放国,仅次于我国和美国。比较起航天燃料(2.5%),混凝土乃至可以排放更多的二氧化碳,一起这也远超越全球农业的排放量(12%)。”——Lucy Rodgers, BBC News

For thousands of sw161years, concrete has been a foundation of the built environment: the most widely used man-made material on the planet. However, as architects, and the public alike, sharpen their focus on the causes and effects of climate cha金珍锡nge, the environmental damage caused by cement has become a subject of unease.

As exhibited in a recent in-depth article by Lucy Rodgers for BBC News, cement is the source of about 8% of global CO2 emissions. The piece was written off the back of the UN’s COP24 climate change conference in Poland and found that in order to meet the requirements o黑芝麻的成效与效果,碳排放量超高的混凝土,还有救吗?,千禧f the 2015 Paris Climate Agreement, annual cement emissions must fall by 16% by 2030.三国杀妖将

“If the cement industry were a country, it would be the third largest emitter in the world – behind China and the US. It contributes more CO2 than aviation fuel (2.5%) and is not far behind the global agriculture 黑芝麻的成效与效果,碳排放量超高的混凝土,还有救吗?,千禧business. (12%).”剑傲全国

-Lucy Rodgers, BBC News

Alexandra and Ainsworth estate / Neave Brown. Image Fernando Pires

混凝土的来历可以追溯到公元前6000年的叙利亚与约旦,别的,比如罗马万神庙等修建也能更明晰地表达混凝土的运用,在19世纪与20世纪,混凝土的运用规模忽然倍增。自上世纪50年代以来,混凝土工业乃至添加了30倍,到了90年代又添加了4倍,原因是欧洲战后修建业的开展,以及90年代之后亚洲的经济添加。

现在,每年出产的混凝土超越40亿吨,开释的二氧化碳超越15亿吨。我国是混凝土与混凝土相关产品的出产大国,其次是印度、欧洲、美国等等。可是,我国混凝土的消费反过来也使得全球混凝土消费自2014年起就稳定在40亿吨左右。在未来,修建商场会逐渐向东南亚以及非洲撒哈拉区域搬运,到了2030年,混凝土产品的用量或许还要添加25%,这样才干跟得上年代的开展。

Although the origins of concrete and cement can be traced back to Syria and Jordan in 6000BC, and more articulately by the Ancient Romans in magnificent structures such as the Pantheon, the 19th and 20th century saw an explosion in cement use. P与敌同行第二部roduction of cement has increased thi36cccrtyfold since 1950, and a further fourfold since 1990, driven by postwar building in Europe, and building booms across China and Asia from the 1990s onwards.

Today, over 4 billion tonnes of cement are produced each year, releasing over 1.5 billion tonnes of CO2. China is the top producer of cement and cement-related emissions, followed by India, the EU, and the US. However, the leveling off of Chinese consumption of cement has, in turn, caused global cement production to level off from 2014 onwards at南涧气候 the 4-billion tonne mark. As the future market雪山神豹s in construction move towards South East Asia and sub-Saharan Africa, it is predicted that cement production may have to increase by 25% by 2030 to keep pace菲兹电胆.

The Barbican Estate / Chamberlin, Powell and Bon Architects. Image Joas Souza

那么,混凝土为什么会成为如此严峻的污染物呢?采石与运送进程占了混凝黑芝麻的成效与效果,碳排放量超高的混凝土,还有救吗?,千禧土排放量的不到10%。BBC从前报导,超越90%的排放可能是来历于煤渣的制造进程,这是混凝土出产的要害要素。

在这个进程中,回转窑的温度会到达1,400C (2,600F),其质料是石灰石、粘土、铁矿石、灰末的混合。这些混合物经过加热会分解为氧化钙与二氧化碳,那么二氧化碳就会开释出来,构成大理石般的灰球,这就是所谓的“煤渣”了,然后煤渣会经过冷却、研磨,再与石灰石、石膏混合,终究构成可以运送运用的混凝土。

So why is cement such a heavy polluter? The blame is frequently laid at the foot of quarrying and transport process, however this only accounts for less than 10% of cement训犬根底教程-attributed emissions. As stressed by the BBC report, over 90% of the sector’s emissions can in fact be attributed to the process of making “clinker” – a key element of concrete.

This process sees a rotating kiln heated to over 1,400C (2,600F), fed with a quarried mix 奥克斯特of ground limestone, clay, iro三峡晚报电子版n ore, and a乌兰巴托不眠夜sh. The mixture is split into calcium oxide and C02, at which point the CO2 is released to leave behind marble-sized grey balls, called clinker. The clinker is then c全木海视频ooled, ground, and mixed with limestone and gypsum to form cement ready for transport.

而当时而言,许多人会不断呼吁运用木材等可继续资料来代替混凝土,一起人们关于混凝土对环境形成的影响的知道也不断提高,然后也会有一些可继续的产品来代替煤渣。最近,英国兰开斯特大学的研究者发现了一种新方法,那就是可以从胡萝卜和根类植物中提取纳米血小板来促进混凝土的混合。别的,Sandra Manso-Blanco博士所开发的“生物感触混凝土”也可以经过结构混凝土的分层来促进苔藓的成长,这种苔藓可以有效地吸收二氧化碳。

Taktl的战略围绕着“少便是多”的概念。其所用的高性能混凝土实质仍然是混凝土,可是其开释的二氧化碳会比传统混凝土要少许多,这说明到达相同的混凝土强度黑芝麻的成效与效果,碳排放量超高的混凝土,还有救吗?,千禧时,这种原资料所开释高韶青在我国遭受的二氧化碳会少一些。

As well as calls to move towards more sustainable primary building materials such as timber, the heightened awareness of the environmental damage caused by cement has led to the growth of new alternatives to the clinker process. Recently, researchers at Lancaster University in the UK unveiled a novel approach of using nanoplatelets extracted from carrots and root vegetables to enhance concrete mixes. Another trend of “bioreceptive concrete”, developed by Dr. Sandra Manso-Blanco, sees structural concrete layered with materials to e邵萱ncourage the growth of CO2-absorbing moss and lichen.

The approach of Taktl, meanwhile, is centered around the i千视眼dea of "less is more." While this ultra-high-performance concrete is still concrete, it produces far less CO2 t黑芝麻的成效与效果,碳排放量超高的混凝土,还有救吗?,千禧han traditional concrete by using les色群s water and by being stronger, meaning you need less of it to achieve the same strength.

Jacob Snavely

为了削减碳排放,加州的Watershed Materials公司也正在研制传统混凝土的代替战略,新式混凝土只运用少数的原资料,降低了二氧化碳的排放量,他们乃至在著作中运用了其间一种产品,期望可以彻底代替传统混凝土。

新闻来历:BBC News

To further-curb runaway 黑芝麻的成效与效果,碳排放量超高的混凝土,还有救吗?,千禧carbon emissions, a California-based company called Watershed Materials is developing alternatives to the traditional concrete block which uses less cement, dramatically reducing the amount of carbon dioxide produced; they even have a product in the works which they hope will offer a widely applicable concrete block alternative which uses no cement at all.

News via: BBC News

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