The timeline of asphalt

From asphalt lake to science

Asphalt is older than you think. It was formed when petroleum came to the surface through cracks in the earth’s crust and mixed with stone and sand. The oil's volatile constituents evaporated and the heavier, thick, syrupy residual product (bitumen) was left over. 

753 BC

The word asphalt is derived from the Greek word asphaltos (άσφαλτος). The Romans called it asphalton and used it to make their baths and aqueducts watertight. The first asphalt road was laid in the city of Babylon. It probably only contained asphalt in the substrate. The top layer consisted of limestone slabs laid contiguously.

1595

Pitch Lake

The British explorer Sir Walter Raleigh discovers Pitch Lake, a natural asphalt lake in Trinidad and Tobago. He uses the syrupy substance to make his ships watertight.

1870

First asphalt concrete

The Belgian Edmund J. Desmedt patents the first real asphalt concrete. He works in the United States at Columbia University in New York City. He is the first to use his invention to construct a new road in Newark and later also for Pennsylvania Avenue in Washington, D.C. He uses the syrup from Pitch Lake as a binding agent.

1900

Bitumen

Inventor Frederick J. Warren patents the modern asphalt as we know it today, with hot bitumen as a binding agent. Bitumen is a thick substance, created as a residual product by oil refineries. Once all the volatile constituents - like LPG, benzene, kerosene, diesel and fuel oil - have been distilled, bitumen is all that is left over.

Ingredients

Asphalt consists of stones, sand, filler material and bitumen. Basalt, limestone and quartzite are some of the stones and sand particles. Limestone and cement are two examples of filler material. Modern asphalt needs to be heated in order to be processed. Asphalt production is not a chemical process like concrete production, where cement reacts with water. Asphalt cools down and hardens.

1907

Oil refining

The emergence of cars resulted in a breakthrough for asphalt. One of the main factors was the increase in oil refineries. Bitumen was thus being produced in ever greater quantities.

1914

Construction of first bituminous roads in the Netherlands. Back then, bitumen was sometimes replaced with tar.

1928

Heijmans enters the picture

Jan Heijmans starts using asphalt.

1940
1945

Porous asphalt 1.0

During the Second World War, the British develop the first porous asphalt for use on military airfields. Porous asphalt finds its way to America during the war. It is used to resolve puddle-related issues on runways after heavy rainfall, and enables aircraft to take off and land at any time. Furthermore, both armies commission studies to improve the sustainability of asphalt, so heavy bombers will also be able to take off and land safely.

1950

The colourful train

Heijmans’ mobile asphalt unit ‘De bonte trein’ (‘The colourful train’) produces bitumated sand when reinforcing the Zuiderzee Works. And the asphalt plant ship ‘Dorus Heijmans’ is used to reinforce dykes along the IJsselmeer polders.

1960

Subsidiary Bitumarin is created. Heijmans, the Koninklijke Maatschappij Wegenbouw and the Hollandse Beton Groep specialize in applying asphalt seabed/riverbed protection and laying asphalt bars underwater as foundations for new dams in the Delta area.

1961

Hydraulic engineering and asphalt

Bitumarin builds various dams and dykes. They use a kind of porous asphalt as dyke cladding, as its open structure enables water to run off the dyke at low tide. Had this not been done, water would have placed pressure on the dyke cladding from the inside. Asphalt mats are placed over dykes or dams like sheets.

1968

The Jan Heijmans

The asphalt ship ‘Jan Heijmans’ is launched. It makes a significant contribution to the Delta Works. The huge vessel lays asphalt mats measuring eight metres wide and 40 metres long on the seabed. They protect the dykes and dams, making sure they do not subside into the soft seabed. Asphalt is produced onboard. The ship laid asphalt mats at all the weak spots in the Eastern Scheldt.

1972

The asphalt factory in Harderwijk produces the first Dutch porous asphalt for a test section on Provincial Road S5 in Ugchelen.

1982

Porous asphalt

Porous asphalt is used on a small scale due to its road safety properties. Heijmans sees another benefit of porous asphalt: anything that is porous will reduce noise. Hence porous asphalt is quieter than non-porous asphalt. Although noise nuisance is not an issue for the government, Heijmans dedicates itself to reducing asphalt-related noise.

1984

Heijmans performs noise measurements with porous asphalt on a road in the village of Zeeland in the province of Brabant. A new science is born. It turns out that finer mixes, combined with a lower rolling resistance, make the asphalt a lot quieter. However, the finer the mix, the greater the chance of the wearing course becoming contaminated and clogged up. A new challenge arises: how do you make roads quieter without affecting their other properties, like lifespan and water drainage?

1987

The Ministry of Housing, Spatial Planning and the Environment instructs Heijmans to conduct scientific research into reducing noise in porous asphalt. To this end, Heijmans joins forces with Vught-based acoustic firm M+P.

1988

Twinlay

All research fails to resolve the conflict between noise reduction and water drainage. But the solution suddenly emerges: double-layered porous asphalt. An innovation that Heijmans dubs ‘Twinlay’. The bottom layer is made of coarse grit, which enables effective water drainage. The top layer ensures very high noise reduction because it has a finer grain size.

1989

The Ministry of Housing, Spatial Planning and the Environment instructs Heijmans to asphalt an old runway at Eindhoven Airport using all variants of porous asphalt, including double-layered porous asphalt. Twinlay proves to be much quieter than single-layered porous asphalt.

1992

Single-layered porous asphalt

By now, single-layered porous asphalt is used as standard on Dutch motorways because it is so conducive to road safety. The material’s open structure and effective resistance to rutting means all water runs off the road surface. Aquaplaning is thus eliminated and traffic is not troubled by poor visibility caused by spraying water.

1998

Rijkswaterstaat instructs Heijmans to asphalt the A4 near Delfland with Twinlay. The road can only be constructed because the asphalt is so quiet. The first stretch of motorway featuring double-layered porous asphalt has now been realised.

2000

Quieter asphalt

Noise reduction starts to play an increasingly significant role in Dutch road-building. That's why quieter porous asphalt is being used more often in larger-scale projects (both single-layered and double-layered).

Fine-tuning asphalt

Heijmans is continuously fine-tuning asphalt mixes. ‘We make all kinds of adjustments during asphalt production’, explains Innovation Manager Gerbert van Bochove. ‘In the past, clients would refer to standard asphalt regulations they had drawn up by themselves. But they are now placing greater focus on the function of the road. For example, the criteria for the project on the A12 Ede – Grijsoord were skid resistance, evenness and noise. This stretch of the A12 has to meet these requirements for 16 years. This drives innovation when making asphalt ever better, quieter and more sustainable.’

2009

Brainjoint

Introduction of the Brainjoint: a quiet, maintenance-free expansion joint.

2013

Air Jet Seal

Heijmans develops the Air Jet Seal technique: a life-extending maintenance method for porous asphalt. A single treatment will extend the lifespan of asphalt by four years.

2014

Greenway LE

Introduction of self-healing asphalt, which is capable of repairing itself thanks to an induction treatment. Greenway LE also introduced, which enables a 25% reduction in CO2.

2015

Recoflex

Heijmans develops the flexible single-layered asphalt surface Recoflex. Properties of the foundation, substrate, intermediate layers and wearing courses are unified in a single layer.

2017

Recoflex Velo

Introduction of the stable, single-layered asphalt surface Recoflex Vélo; the cycle path version of Recoflex. Comfort of unsurfaced forest trails on popular cycle routes is improved with a single intervention.