Clay stronger than concrete? H2PA, ecological construction
Two hundred tons of sand are needed to make a single house, even as the coastlines continue to weaken, with a complete disappearance of the noble sand estimated for the end of the century. In an attempt to provide alternatives to this vast pollution, two French people have filed a patent for H2PA, a manufacturing technique allowing the production of clay cement with 20 times less CO2 emissions.
Find an ecological and economical alternative to conventional cement
In 2016, cement concrete still reigns supreme in construction. However, this generates 20% of the CO2 produced worldwide, and with 7 billion inhabitants, the demand for housing continues to increase and worsen the situation. Cement production requires burning limestone in kilns reaching 1300 ° C, using tons of water and sand. The latter material is itself threatened by industrial extraction, a source of maritime erosion.
By 2100, on this momentum, all French beaches should have disappeared. However, many alternatives to concrete cement have existed for several years, such as hemp concrete and flax concrete, which are completely ecological and have insulating properties far superior to their rivals. A potential ecological and economic windfall for France, the second largest producer of hemp in the world behind China, and the largest producer of flax in the world with 500,000 tonnes per year. Alas, the linen concrete still remains completely confidential, in the disturbing shadow of the cement concrete.
In an attempt to stem this dark phenomenon, the engineer David Hoffmann and the CEO of the company Argilus Julien Blanchard have examined the interest of clay, available everywhere in the world and in much larger quantities than limestone. . Together, the two French are working on a new clay manufacturing method, called HP2A (High performance alkaline activation), for which they filed a patent in February 2015.
According to their website, “ HP2A technology, an alternative to Portland cement, eliminates the need for marine sand and meets the needs of tomorrow's construction: green materials that are economically realistic and make it possible to reduce the carbon footprint on the site. whole planet. “And in fact, the production of their clay cement does not require cooking, consequently reducing the expenditure of CO2: 50 kg for a ton, against 1000 kg for a ton of conventional cement. Much more ecological, the HP2A technique is also slightly more economical.
A clay cement for sustainable development
In addition to its carbon footprint which is far more flattering than cement concrete, the clay cement offered by the two French has a much higher mechanical resistance, and a much stronger resistance to chemical attacks. To form concrete, clay cement can be mixed with non-noble sands (not coming from rivers and beaches, but for example from large deserts considered to be little or not exploitable), waste from construction or hemp, l one of the new flagship eco-materials in construction.
Another major advantage in favor of sustainable development, clay cement can be recycled for nearly half a century. Moreover, according to the two inventors, their invention would be more flexible than conventional concrete, favoring the delicate realization of rounding.
But in order not to preach in the desert, a great idea needs support. And in the field of concrete, competition is fierce against the powerful lobbies of cement concrete, relentlessly reigning in the world market. As the two inventors rightly affirm, “ French innovation exists but it needs funding and economic partnerships capable of transforming a start-up into a national industrial flagship. In order to really change the world, HP2A technology relies on the support of the French public authorities and a few daring manufacturers . "
The giants Airbus, Total and Michelin have already shown their support for David Hoffmann and Julien Blanchard. Their clay cement should be produced and marketed as early as next year.