Whilst there’s no shortage of sand and gravel in Devon and the UK, it’s not the same in other countries. We posted about the future for sand and gravel production last year:
If flatlining sales figures, planning difficulties and rising energy costs are anything to go by, the business outlook for UK sand and gravel production is not spectacular.
Elsewhere in the world there are other problems, with looming shortages of sand – Germany being the latest country to declare problems:
Germany desperately needs more sand for industry. But a lack of planning foresight, the politics around mining sites and the needs of coastal communities are making the search ever grittier.
We also wrote:
In recognition of these difficulties, and the need to move towards a circular economy, more and more construction waste is thankfully being recycled. Only last week, the UK's largest recycling plant for construction and demolition waste opened in West Lothian, which promises to turn 400,000 tonnes of construction, demolition and excavation waste per year into sand and gravel.
This week, in an effort to stop millions of tonnes of fine-grained building rubble ending up in landfills, results from Germany’s Fraunhofer Institute – a novel approach to recycling construction waste – will be showcased at a Munich trade fair:
The construction industry is one of the most resource-intensive sectors of the German economy. The nation’s buildings constitute a vast store of raw materials, harbouring some 100 billion metric tons of materials that could be recovered and returned to the material cycle at the end of their service life. Four Fraunhofer Institutes have joined forces in the BauCycle project to kick-start recycling of sand and gravel fine particle fractions that cannot be reclaimed today for reuse in further construction projects. The research team will present the results of their work at the 2019 BAU trade fair in Munich from January 14 to 19.
“Building sand is not superabundant; in Europe, for example, sand is in short supply in Sweden and France. The conventional method of treating rubble is to crush it. Components of less than two millimetres are sieved out and end up in landfill. If this fine-grained building rubble – which consists mainly of sand-lime bricks, bricks, concrete and small amounts of gypsum – were to be recycled, this could redress the sand shortage over the long term,” says Fraunhofer IBP scientist Dr. Volker Thome, the project’s manager.
In the best-case scenario, four clean aggregates may be recycled and reused to produce aerated concrete, a light building material with good thermal insulation properties. It is suitable for building two-story houses and as indoor insulation. Tests have shown that aggregates of concrete and sand-lime bricks are also recyclable and can serve as a secondary raw material for making competitive grades of aerated concrete. The scientists achieved the best results with a mix of 80 percent sand-lime bricks and 20 percent reclaimed concrete. Another project finding was that a combination of bricks and recovered concrete can be used to make geopolymers, a cement-free building material that is strong and acid-resistant, much like concrete. Geopolymers have the added advantage of a very low carbon footprint.
