InfraStructures - December 2008 / January 2009 - 100 Years of Ammann Asphalt Mixing Plants

100 Years of Ammann Asphalt Mixing Plants

Dust penetrates every crack and pore, it is difficult to breathe and there is dirt everywhere. With a few exceptions, this was the grim reality on the world's arterial roads at the start of the 20th century. But conditions started to change after a Swiss physician completed the first short section of road made from a mix of viscous tar and gravel in Monaco - and the asphalt road was born.

Ammann has been involved in the story from the very beginning of this new development. This family-owned company, based at Langenthal in Switzerland, acquired the patent for tarmacadam machines in 1908 and went on to produce the first continuous ballast coating machine. The same year saw the First International Roadbuilding Congress in Paris. Ammann has been driving innovation ahead in the asphalt sector for one hundred years, and the story continues today: as the development process moves forward, production processes are improved, output is increased and energy requirements are cut.

Key Developments
Mineral pitch (natural asphalt) has been known as a binding agent and construction material for over 4000 years. Back in 1839, for example, it was used to asphalt the Jungfernstieg in Hamburg. Short sections of road in France, Austria and the USA were built manually in the 19th century, but the cost and effort were enormous. The situation saw no significant improvement until the advent of mechanical asphalt processing in the 20th century. Tar began its rise to prominence as a binding agent for road surfaces in 1902. Bituminous base course mixes were introduced as oil refineries became more widespread in the mid-20th century - displacing tar, which was actually banned later on due to the carcinogens it contains.

As motorized transport appeared on the scene and gradually increased from the end of the 19th century onwards, natural roads were no longer able to cope. Dust was one major problem. Prince Albert?I of Monaco met Dr. Ernest Guglielminetti during a medical conference. He asked him what could be done to control the dust stirred up by motor vehicles. "Since cars have been racing along our corniche, we've been breathing dust from dawn till dusk. The flora that used to be so colorful seem to be lacklustre, and there are no more fresh living flowers", said the Prince.

Ernest Guglielminetti, who was born in Brigue, Switzerland, studied medicine before travelling around the world. His idea of mixing sand, gravel and hot tarmac came to him while working in Java, Sumatra and Borneo, when he noticed that the wooden floors of the hospitals there were coated with tar in order to render them waterproof.

His answer to Prince Albert was the treatment of a 40 m section of the road using this process. This small step was a breakthrough for the idea of using gasworks tar for dust-free roads. Dr. Guglielminetti who had not patented the process did not make a fortune from his invention but gained recognition in 37 countries around the world and even acquired the humorous nickname of "Dr. Goudron" (or Dr. Tar in French).

The next objective was to overcome the properties of raw tar which were damaging to health. Heinrich Aeberli, director of Roads for Zurich Canton, developed a process in which the tar-coated aggregate was kept warm for as long as possible before it was laid: this largely eliminated its health-damaging properties. Heinrich Aeberli obtained a German Reich patent for this process.

Until then, the Ammann company of Langenthal in Switzerland had mainly manufactured agricultural machines. Together with Mr. Aeberli, the firm then developed the first continuous-operation macadam machine, which was patented in 1908. The first trials with the tar coating were carried out on the Jurastrasse in Langenthal - and for many years afterwards, the popular name for the road linking the village centre and the rail station was the Macadam Road.

Breathtaking development - but resources are protected
The technical advances have been fantastic over the last hundred years. Cutting-edge software-based control technology makes today's asphalt mixing plants simple and efficient to operate. Tightening of the clean air regulations is reducing the emissions from the plants. The current focus is on the goal of raising the processed portion of reclaimed asphalt (RA) towards 100%.

The challenges of the future are as fascinating as they are ambitious: CO2 emissions are being reduced still further. Ultramodern mixing processes will enhance production and encourage the use of low-temperature asphalt. The global demand for roads is still far from being met. At the same time, the challenge of maintaining highways that have already been built is growing apace. In these areas too, Ammann is the technology leader.

With more than 3000 asphalt mixing plants in operation across the globe, Ammann is the global market leader in the sector.

Ammann is a leading supplier of machines, systems and services to the construction industry with core expertise in asphalt and road building worldwide. Driven by an entrepreneurial spirit, the family-owned business founded in 1869 is now in the fifth generation. Even in difficult times Ammann is a reliable partner for long-term collaboration.

Source: Ammann