混凝土是最常用的建筑材料，但也是对环境污染最大的物质之一。基于生物建筑技术的自愈合混凝土能够使材料进行自我修复，从而防止裂缝影响建筑物的结构完整性。
Concrete is the most commonly used construction material, yet it also ranks among the most environmentally taxing substances. Self-healing concrete based on bioconstruction techniques, enables the material to repair itself, thereby preventing cracks from compromising the structural integrity of buildings.
根据国际能源机构（IEA）的一份报告，混凝土生产所排放的二氧化碳占全球总量的 8%。这种对环境的重大影响促使人们寻找替代品，以减少这种材料的生态足迹。为了实现这一目标，人们正在努力开发各种对环境影响较小的混凝土，如粉煤灰混凝土、再生塑料混凝土、低碳混凝土或自愈合混凝土。
According to a report by the International Energy Agency (IEA), the production of concrete is responsible for 8% of global CO2 emissions. This significant environmental impact has prompted the search for alternatives to reduce the material’s ecological footprint. In line with this objective, efforts are being made to develop various types of concrete with lower environmental impacts, such as fly ash concrete, recycled plastic concrete, low-carbon concrete, or self-healing concrete.
什么是自愈合混凝土
WHAT IS SELF-HEALING CONCRETE
混凝土以其坚固耐用而闻名，但随着时间的推移，它往往会因气候条件、应力和超负荷而老化，从而形成裂缝。修复这些危及结构安全的裂缝通常是在外部进行表面处理。然而，自愈合混凝土可以从内部修复裂缝，防止裂缝扩展。
Concrete is renowned for its robustness and durability, yet it tends to deteriorate over time due to climatic conditions, stress, and overloads, which lead to the formation of cracks. Repairing these cracks, which compromise the safety of structures, is typically done on the exterior using surface treatments. However, self-healing concrete repairs cracks from the inside, preventing them from spreading.
自愈合混凝土项目
Self-healing concrete projects
2015 年，荷兰代尔夫特理工大学的微生物学家 Henk Jonkers 首次展示了具有嵌入式细菌功能的自愈合混凝土。这项技术是将含有细菌菌株和乳酸钙的胶囊引入混凝土中，作为细菌的养分。当混凝土出现裂缝并进水时，这些胶囊就会破裂，使细菌产生凝固的不溶性石灰石。这些细菌可在混凝土建成后的 200 年内保持休眠状态。鉴于其独特的特性，这种仍处于试验阶段的建筑材料被称为 "活混凝土"。
In 2015, Henk Jonkers, a microbiologist at Delft University of Technology in the Netherlands, presented the first self-healing concrete, featuring embedded bacteria. The technique involves introducing capsules containing bacterial strains and calcium lactate into the concrete, which serves as a nutrient for the bacteria. When cracks appear in the concrete and water enters, these capsules break open, allowing the bacteria to create solidified and insoluble limestone. These bacteria can remain dormant in the concrete for up to 200 years after construction. Given its unique characteristics, this building material, still in the experimental stages, is known as living concrete.
2021 年，马萨诸塞州伍斯特理工学院的研究人员开发出一种自愈合混凝土，其中含有一种酶，能与空气中的二氧化碳发生反应，生成碳酸钙晶体，模拟混凝土的特性，有效填充和密封裂缝。这种模型的灵感来自人体，在人体中，碳酸酐酶将二氧化碳从细胞转移到血液中。这种混凝土可以在 24 小时内修复裂缝，而使用细菌的生物混凝土则需要大约三周的时间才能达到同样的效果。
In 2021, researchers at Worcester Polytechnic Institute in Massachusetts developed a self-healing concrete incorporating an enzyme that reacts with CO2 in the air to produce calcium carbonate crystals that mimic the properties of concrete, effectively filling and sealing cracks. This model is inspired by the human body, where the enzyme carbonic anhydrase transfers CO2 from the cells to the bloodstream. This concrete can repair cracks in just 24 hours, whereas bio-concrete with bacteria takes approximately three weeks to achieve the same result.
在美国，国防高级研究计划局（DARPA）正在开展 BRACE 项目（老化混凝土建筑的生物启发修复），以开发能够自我修复混凝土裂缝的技术。该项目从促进生物生态系统和生物体内持续修复的血管系统中汲取灵感。这种混凝土具有自我修复能力，就像手臂上的伤口一样。通过这个项目，他们希望减少维修时间和成本，同时延长基础设施的使用寿命。
In the United States, the Defense Advanced Research Projects Agency (DARPA) is working on the BRACE project (Bio-inspired Restoration of Aged Concrete Edifices) to develop technologies capable of self-healing cracks in concrete. This project draws inspiration from the vascular systems that facilitate continuous repair in living ecosystems and organisms. This concrete possesses the ability to self-heal similarly to how a cut on your arm would. With this project, they aim to reduce the time and cost of repairs while extending the useful life of infrastructures.
自愈合混凝土有哪些优点？
WHAT ARE THE BENEFITS OF SELF-HEALING CONCRETE?
自愈合混凝土在建筑中的优势不胜枚举：
The advantages of self-healing concrete in construction are numerous:
它可以延长基础设施的使用寿命，减少频繁维护的需要。
It extends the useful life of infrastructures, reducing the need for frequent maintenance tasks.
它通过延长混凝土的寿命来减少碳排放，从而减少对新材料生产的需求，进而减少排放和废物。
It reduces carbon emissions by extending the life of the concrete, thus decreasing the need for new material production and consequently reducing emissions and waste.
它通过降低结构坍塌的风险来提高安全性。通过自我修复细小裂缝，可确保结构安全，防止水渗入，腐蚀混凝土中的钢筋。
It improves safety by reducing the risk of structural collapse. By self-healing small cracks, the structure is secured, preventing the penetration of water that can corrode the steel reinforcement within the concrete.
它降低了结构的维修成本，仅欧盟每年的基础设施维护费用就高达 60 亿欧元。据估计，自愈合混凝土可将这些成本降低一半。
It reduces repair costs for structures, which in the EU alone amount to EUR 6 billion annually for infrastructure maintenance. Estimates suggest that self-healing concrete could reduce these costs by half.
自愈合混凝土在现实生活中是如何使用的？
How is self-healing concrete used in real life?
BRACE 研究主要是在军事领域开展的。在最初阶段，重点是为大型永久性结构（如核弹发射井）开发自修复混凝土。在第二阶段，开发范围将扩大到临时结构，如飞机场。他们还计划将工作范围扩大到民用建筑，包括道路和高速公路的维修以及住宅建设。
BRACE studies have been primarily developed in the military field. In the initial phase, the focus was on developing self-healing concrete for large and permanent structures such as nuclear silos. In the second phase, the development will expand to include temporary structures such as aerodromes. They also plan to extend their efforts to civil structures, including the repair of roads and highways, as well as the construction of homes.
代尔夫特大学开发的生物混凝土主要用于灌溉渠道、桥梁和道路等土木工程项目。它已在荷兰、中国、美国和欧洲成功应用。
Bio-concrete developed by Delft University is utilized in civil engineering projects, primarily in irrigation channels, bridges, and roads. It has been implemented successfully in the Netherlands, China, United States and in Europe.
自愈合混凝土提供了一种可持续、耐用和环保的解决方案，有望彻底改变建筑业。然而，与传统混凝土相比，自愈合混凝土的高成本仍然是其广泛应用的一大障碍。
作者 | Elvira Esparza
标题 | 《 WHAT IS SELF-HEALING CONCRETE AND HOW DOES IT PROMISE TO REVOLUTIONIZE THE FIELD OF CONSTRUCTION》
Tomorrow.Observatory | 明日观察#66
Tomorrow.Observatory | 明日观察#65
