瓦勒·阿尔·阿瓦尔的办公室设在迪拜的老城区德伊勒，建在一片盐沼（或称“萨布哈”（sabkha））上。这种地质构造的特点是缺乏植被且含盐量极高。这位黎巴嫩建筑师和他的商业伙伴、日本建筑师寺本健一（Kenichi Teramoto）在2021年威尼斯建筑双年展上主持设计了阿联酋国家馆，他们从阿联酋的萨布哈中汲取灵感，一举荣获了“最佳国家参与金狮奖”。展馆名为“湿地”，探讨了能否利用从海水淡化厂回收的含盐废水制造可持续的建筑材料。
“水泥行业直接排放的二氧化碳占全球直接排放总量的7%至8%”
将盐用于建筑已经有千百年的历史了。埃及西部的绿洲城市锡瓦就建立在一片萨布哈上，公元前10000年，这里发展成为人类早期文明的发源地之一。当地的房屋是用传统建材kersheef建成的，其主要成分是盐。这些房子至今依然屹立不倒。不过随着时间的推移，这种传统做法已经消失不见了。同世界其他地方一样，迪拜大量使用混凝土，对环境造成了严重影响。混凝土的基本成分是水泥，而水泥行业直接排放的二氧化碳占全球直接排放总量的7%至8%。真正的问题出在水泥中的粘合剂——石灰，碳酸钙受热之后才能产生氧化钙（石灰），而氧化钙会释放出作为副产品的二氧化碳。
© 费德里科·托拉（Federico Torra） “湿地”项目于 2021 年在威尼斯建筑双年展上获得了“最佳国家参与金狮奖”，探讨了利用从海水淡化厂回收的含盐废水制造可持续的建筑材料的方法。
阿尔·阿瓦尔和寺本健一在日本等国也设有办事处，这些国家历来使用竹子等当地物产作为建筑材料，现在也是如此。但在阿联酋，要使用当地材料很困难。过去，建筑行业曾经依靠珊瑚作为建材。但阿联酋人口在过去50年里从几十万增加到了900多万，大规模利用珊瑚资源已经不可行了。阿尔·阿瓦尔说：“身为建筑师，真的需要了解自己的责任所在。在阿联酋找不到木材，也没有竹子。我们必须打破思维定式，寻找替代方案，努力让我们的工作有益于气候。”
就在阿尔·阿瓦尔寻找水泥的替代品的时候，他注意到了占阿联酋国土陆地面积5%以上的萨布哈。
阿尔·阿瓦尔和来自沙迦美国大学的科研人员团队分析了萨布哈中的矿物质和盐类，发现其中含有氧化镁。基于这一发现，纽约大学阿布扎比分校工程学助理教授凯末尔·切利克（Kemal Celik）帮助他们找到了一种用氧化镁替代石灰的方法，用这种方法制造出来的新型合成砖块后来被用于“湿地”展馆的构建。
以盐水为解决之道
阿尔·阿瓦尔表示，可以将萨布哈作为激发灵感的源泉，但不能将其视为物质来源，攫取其中的资源是一种“犯罪”。萨布哈也是碳汇。“要是我们说，‘我们来开发萨布哈吧’，我想它们很可能撑不过五年。”与其破坏这些自然环境，不如使用源于海水淡化厂的盐水来解决问题。
在建筑中使用盐水的技术目前还处在起步阶段。阿联酋国家馆馆长莱拉·宾布雷克（Laila Binbrek）表示：“这只是一个开端，希望终有一天能够成为现实。”阿尔·阿瓦尔和切利克此后一直孜孜不倦地研究这个问题，并于2023年11月在“迪拜设计周”上展出了新的设计原型。
© 图片来源：威尼斯双年展阿联酋国家馆和waiwai/摄影：瓦勒·阿尔·阿瓦尔（Wael Al Awar） 鲁韦斯萨布哈位于阿布扎比以西约 240 公里处。这种高盐度地质构造是接触海水后的干旱地区的特征。
“我们不能再走资源开采的老路了，
必须考虑循环经济问题”
对于任何建有海水淡化厂的国家来说，氧化镁都是一种切实可行的解决方案。但这种物质不是一种应当出口的材料；人们应当就地取材，在当地寻找解决方案。他指出：“气候危机问题源自人们对普遍物质性的认识，回顾过去就可以发现，人类的建设从来只考虑自身环境，不会顾及他人的环境。”
阿尔·阿瓦尔补充说，迪拜的建筑物不应该看起来像是新加坡建筑的翻版。他说：“我们不能再走资源开采的老路了，必须考虑循环经济问题。我要敦促每一位建筑师仔细审视自己的城市，看看有哪些工业废弃物可以利用起来。”莱拉·宾布雷克对此表示赞同：“有时你可能没有意识到，其实解决之道就在眼前。”对于阿尔·阿瓦尔来说，解决之道就是他办公室下面的那片萨布哈。
Solving a concrete issue with salt in Dubai
Could brine waste from seawater desalination plants offer an alternative to cement? This solution is put forward by Wale Al Awar who advocates for eco-responsible architecture.
Katy Gillett
Journalist based in Dubai, the United Arab Emirates (UAE)
Wael Al Awar’s office sits in In Deira, an older area of Dubai. The building was constructed over a salt flat, or sabkha, a geological formation characterized by a lack of vegetation and very high levels of salinity. It was the sabkhas of the United Arab Emirates that inspired the Lebanese architect and his Japanese business partner, Kenichi Teramoto, in their curation of the 2021 UAE National Pavilion at the Venice Biennale of Architecture, which won the Golden Lion for Best National Participation. Called “Wetland”, the exhibition examined the potential for making sustainable building materials using recycled brine waste from desalination plants.
“The cement industry accounts for 7 to 8 per cent of the world’s direct CO2 emissions”
Salt has been used in buildings for centuries. Siwa, an urban oasis in western Egypt, was founded on a sabkha and became the home to one of the earliest civilizations in 10,000 BC. Abodes were created using kersheef, a traditional material mostly assembled from salt, and these still stand today. But over time, the tradition has been lost. In Dubai, like in other parts of the world, concrete has taken over, with serious consequences for the environment. The cement industry is responsible for about 7 to 8 per cent of the world’s direct CO2 emissions and it’s a fundamental building block for concrete. It is lime, the binder in cement, that is the real problem, as calcium carbonate has to be heated to produce calcium oxide (lime) which releases CO2 as a byproduct.
Off the beaten track
Countries such as Japan, for example, where Al Awar and Teramoto also have an office, have historically built with local materials such as bamboo – and still can. In the UAE, however, the use of local materials is a challenge. In the past, the building sector relied on coral. But large-scale use of this resource is not a viable option for a population that has grown from some hundreds of thousands to over nine million in the last fifty years. “As an architect, you really need to understand what your responsibility is,” says Al Awar. “In the UAE, there is no wood or bamboo. We had to really think outside the box to find an alternative and try to do what was good for the climate.”
As Al Awar sought alternatives to cement, he came across the sabkhas, which account for more than five per cent of the country’s land mass.
Al Awar and a team of scientists from the American University of Sharjah analyzed the minerals and salts and found magnesium oxide. Building on this discovery, Kemal Celik, an assistant professor of engineering at New York University Abu Dhabi, helped find a way to replace lime with magnesium oxide to create new synthetic blocks that were later used in the structures that formed Wetland.
Brine as a solution
Sabkhas may have been the inspiration, but they were not the material source, as extracting from them would be a “crime”, says Al Awar. They are also carbon sinks. “If we say, ‘Let’s build with sabkhas’, I don’t think they would last five years.” Rather than destroy these natural environments, the solution was to use brine from desalination plants.
The UAE – the second-largest desalination market in the world after Saudi Arabia – generates about 14 per cent of the world’s total desalinated water output, according to the Abu Dhabi Department of Energy. These plants supply potable water to millions, but the leftover waste of highly concentrated saltwater goes back into the Gulf, increasing its salinity. This has an impact on marine and coral life. “We thought this is a win-win situation where we can take this byproduct and really work with it,” says Al Awar.
The technique of using brine in construction is still in its very early stages. “It was just the beginning of what eventually could be and hopefully will be,” says Laila Binbrek, the director of the National Pavilion UAE. Al Awar and Celik have been looking into this since then, and exhibited a new prototype at Dubai Design Week in November 2023.
“We need to move away from resource extraction and think of a circular economy instead”
Magnesium oxide could be a feasible solution for any country with desalination plants. But it is not a material that should be exported; solutions need to be found close to home. “The problem of the climate crisis is the idea of universal materiality,” he says. “If you look to the past, people built from their environment, they never built from other people’s environment.”
A building in Dubai shouldn’t look like a building in Singapore, adds Al Awar. “We need to move away from extraction and think of a circular economy. I urge each architect to look at their city and see what the industrial wastes are. Laila Binbrek agrees. “Sometimes you don’t realize the solution is probably right under your nose.” Or in Al Awar’s case, right under his office.
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