IBMB_en > Department of Organic and Wooden Based Materials > Research projects > Development of a mineral road surface without using binders

Development of a mineral road surface without using binders

Project number AIF KF2178806K13

According to the requirements for main roads: highways of 1,900 km are to be newly built, 2,200 km are to be expanded to six or more lanes, and 5,500 km of A-roads (Bundesstraßen) are to be reconstructed and newly built. In addition, about 13,000 km of the existing motorway network is subject to ongoing restorations.

In view of the use of cement-bonded construction materials (concrete), the shortage of resources and the negative impact of CO2 emissions on the environment which occur during the production of cement are to be considered as major disadvantages. Due to the increasing demand in the field of road engineering, future-oriented construction methods are desired by protecting resources and using environmentally-friendly construction materials.

So the challenge of this project is to develop more ecological and sustainable construction materials as an alternative for the production of road surfaces (base course and cover layer) and which don’t require the use of binders. Sands, which have not been usable so far, and other materials that are available in large quantities shall be used for developing new products that combine ecological benefits as well as better road characteristics.

In comparison to the latest state of technology in the field of road engineering, the innovation of this road surface is that for the first time a construction material is being developed whose compound is not created by adding a complex chemical binder but by using different physical and chemical principals while supplying heat.

Moreover, an improvement of the durability of the road surfaces is expected. Chemical attacks, e.g. through thaw salts, have a negative impact on binders and often cause microstructural damage. These attacks will be avoided if binders are not used.

An economic advantage is that expenses may be saved by avoiding the binders which are used in quite large quantities in the construction or restoration of new roads. Furthermore, it is envisaged to use reasonably priced residual materials from different industry sectors for manufacture. This will allow reducing costs in production and processing of the new building material.

Fig.1 Image of backscattered electrons of a broken sandstone with overlaid X-ray intensities of the element C1. Problem here: ascending water on facing bricks of a building in Braunschweig.
Fig.2 Same image as Fig.1 but here with S-Intensities