Why the construction industry can no longer rely on sand
There is little that there is as much as the proverbial sand by the sea. In the meantime it has become so scarce that it is mined under life-threatening circumstances and traded illegally. In this blog post you can read why the construction industry has to find alternatives to this raw material as quickly as possible.
In ancient times, attempts were made to make infinity tangible by the number of grains of sand. At that time it was thought that there were not enough numbers to be able to grasp this unimaginable quantity. In his writing "Sand Calculator" Archimedes tries to prove that the number of grains of sand in the universe can be measured. Today we know: No matter how high this number is, it is definitely too small to satisfy the modern world's hunger for this seemingly inexhaustible resource. Sand lies on beaches, on the seabed and in the desert in masses. However, the material needs tens of thousands of years to "regrow". This is because tiny granules are created by erosion - and this process takes time.
Sand demand tripled within 20 years
According to United Nations figures, the worldwide annual consumption of sand and gravel is currently more than 50 billion tons. In just 20 years, demand has tripled. This is mainly due to the boom in the construction industry. It primarily uses reinforced concrete and consists of two thirds sand. In view of urbanization, the construction industry will need even more of the now scarce resource in the future. By 2050, two-thirds of the world's population will live in cities. Currently, 55 percent of the 7.62 billion people do so. But the housing and infrastructure for the new townspeople have yet to be created. In addition, sand is also found in many other products that we cannot do without: In soap and detergents as well as in any computer or solar panel (silicon). Glass is also made of sand. And even the food and wine industries need sand - in the form of silicon dioxide.
Sand from the desert is no solution either
These impressive numbers seem ridiculously small compared to the size of the desert areas of this earth. These vegetation-poor zones occupy at least one fifth of the land area. Although only 20 percent of the deserts are classic sandy deserts. Nevertheless, the enormous mass of quartz sand that lies here or better moves should be able to satisfy the growing hunger of the modern world? Unfortunately, this abundant material is not suitable for concrete production. The grains are too fine and too round. They lack the edges that provide the necessary friction. Only sand from rivers and seas is suitable for concrete.
Sand for Dubai lets Indonesia's islands sink into the sea
This fact means, for example, that the desert state of Dubai, blessed with sand, has to import sand from Indonesia for its buildings. Sand mining there has taken on proportions that are increasingly robbing the Southeast Asian country of its own territory. It is said that more than two dozen islands have already disappeared. Many countries in Southeast Asia have already banned the export of sand. However, this is still being traded - albeit illegally.
The Sand Mafia rages in India
Especially active - and aggressive - is the Sand Mafia in India. The poorest of the poor recover the coveted good at night under life-threatening circumstances: Without any equipment they dive down to a depth of 15 meters into the sea to carry up to 40 kilograms of sand to the surface with a bucket. In Morocco, which with its mild climate and low prices not only boosts holiday makers but also second home owners, the local construction industry illegally obtains some of the sand from its own beaches. With it it then establishes the desired holiday domiciles and destroys at the same time the argument, which lets rich foreigners enjoy their time-out here. Since the sand shovelled by workers into baskets and transported away with donkeys is only conditionally suitable for concreting because of its salt content and various impurities, the buildings are also at risk of collapsing. In short: In Morocco, potential second home owners are digging up the beaches in order to house them in dwellings that may soon fall on their heads.
Sand mining destroys environment and requires new buildings
No matter if by extraction at the coast or by recovery from the seabed - sand mining leads to a decrease in the number and extent of beaches all over the world. These areas do not only serve as an argument for tourists to attract paying guests. Beaches also protect the interior from natural disasters such as floods, storm surges or tsunamis. If there is no sand above or below sea level, there will be a shortage of groundwater and subsidence - as has already been seen in the Mekong Delta and other coasts in Southeast Asia. Seawater penetrates deeper into the interior of the country and salinizes soils and drinking water. Sand mining under water, in turn, damages the marine ecosystem. The swirling substances kill seaweeds and corals, which in turn would have protected the coasts from erosion as natural breakwaters. The inhabitants of destroyed coastal areas or disappeared islands in turn increase migration and construction activity. After all, they need new housing and infrastructure in their new home. A vicious circle: because the demand for sand is high, it is being removed in more and more areas. This damages them to the point of uninhabitability, which is why the demand for concrete for buildings and thus sand continues to rise.
Sand is also scarce in Germany
In Germany, however, there is no shortage of sand - theoretically. The German Federal Institute for Geosciences and Natural Resources (BRG) announced in a press release in February 2018 that, on the one hand, the material is available in "an almost infinitely large quantity". At the same time, however, the authority warned that sand could soon become scarce in our latitudes. The majority of the deposits are located in areas that are already being used elsewhere: Either the areas are already built over or serve as water, nature and landscape conservation areas. It is likely to be difficult to operate sand pits here.
Will the future lead the construction industry into the desert?
The aim of the construction industry must therefore be to find a way out in the future with much less sand. Or to develop new and above all more sustainable sources. Four students from Imperial College London seem to have found one of these. Their start-up Finite has developed a composite material that has similar properties to bricks or concrete and is also recyclable. The material can be easily produced from organic binders and desert sand. The German company Polycare Research Technology also uses the desert sand, which is available in almost infinite quantities, to produce polymer concrete. The sand is simply mixed with resin and used to cast oversized LEGO bricks. The innovative building material enables even laymen to build their own houses from it, thanks to the instructions supplied. By the way, they account for only 15 percent of the CO2 load of a comparable structure made of conventional concrete. However, Polycare does not intend to enter the construction business itself, but to provide the factories that produce the polymer concrete. A test factory has already been set up in Namibia.
Wood and clay offer alternatives
Of course, there are many other ways that could lead out of the dilemma with building sand. One possibility is to revert to good old wood as a building material. Even skyscrapers can now be built from the traditional building material with an almost unbeatable CO2 balance. And clay, which has been considered the building material of poor people for centuries, is also a suitable alternative. The probably most important step, in order to fight the sand shortage with all its negative accompanying phenomena, would be it to act lastingly and in cycles to think. Anyone who already considers during the planning stage how to remove or recycle a building after it has reached the end of its service life may not necessarily choose reinforced concrete as the basic material.
Conclusio: Why the construction industry can no longer rely on sand
For many years, the construction industry has followed a course that has ultimately led to a dead end. At a time when sustainability is no longer a good thing but a legal requirement, the pressure to break new ground has risen sharply. There are paths that lead out of the dilemma. Some of them are based on new inventions. But even a look into our own past shows alternatives to the status quo, which has little promise for the future: because our ancestors were already very good at building with nature and extracting new building materials from old walls.
Born and raised in Vienna. Since 2012 she has been in charge of Business Development at LEAD Innovation with the functions marketing, sales and communication.