“tecRoad“ Special Bitumen is a rubber modified bitumen which, based upon its initial development in the USA, has since 1986 been subject to continual further development first by CTS and subsequently by Narca.
The rubber modified CTS Special Bitumen is currently manufactured at a static mixing plant and transported to works location by tanker lorries. Travelling distances of up to one day’s journey time are coverable under such conditions of transportation.
Current CTS Special Bitumen is storable for about 3 days. This time limit necessitates the effective advance planning of its usage.
From summer 2005 onwards, a new kind of “tecRoad” Special Bitumen will become available, which will be a highly concentrated rubberised bitumen granulate material transportable in portion sacks, Big-Bags and, at a later date, also in bin containers. This granulate can be stored for several months without loss of quality.
The granulate is placed directly into the mixing mechanism of the asphalt mixing device, at which point it mixes quickly with the original bitumen. In this way, industrial handling is made considerably simpler, and more favourable levels of cost achieved.
As further product variations, similar concentrates will be made in such a way as to be able to be used as alternatives to PmB and PmB/H, with the advantage that during transportation and storage as a solid material at ambient temperature, transportation and storage are both simplified and small amounts may also be easily managed.
An advantage in terms of cost is to be expected in comparison with PmB and PmB/H.
The advantages of the „tecRoad“ Special Bitumen and its product properties etc. can be seen from the reports, “Das gummimodifizierte „CTS“ – Spezialbitumen“, (EN: “The rubber modified ‘CTS’ Special Bitumen”) as well
as “Vorteile des Einsatzes von gummimodifiziertem Bitumen im offenporigen Asphalt“ (EN “The advantages of the use of rubber modified bitumen in open porous asphalt”).
Up to now, roughly 475 km of road surfacing in German speaking countries has been completed using ‘CTS’ Special Bitumen, and roughly 450 km of SAMI surface layering on high level road network surfaces (dual carriageway motorways).
The principal field of application is the noise-minimising drain asphalt, Flüster-Asphalt®, (EN: Whisper Asphalt), which is a CTS-registered trademark.
However, loose chippings asphalts and binding agents are also made with “tecRoad” Special Bitumen, as well as so-called SAMI – layers, as a fissure covering method during the surfacing of concrete paving and as sealant used underneath drain asphalt.
“tecRoad” Special Bitumen is a high value elastomer-modified binding agent. The ”tecRoad“ – Premium special bitumen concentrate contains roughly 35 – 40% rubber. The “tecRoad” –Standard concentrate contains 30 –35% rubber. The rubber is chemically and physically integrated into the bitumen.
The high levels of viscosity, not usually found in polymer bitumen, allow for this kind of bitumen to be spread at high levels of film thickness. Using this method, elastic membrane layers (SAM – and SAMI layers) can be manufactured which are suited for use as bridge sealants.
If these membranes are used as stress-absorbing intermediate layers (SAMI) underneath an asphalt surface, then the thickness of the asphalt layer can be substantially reduced (refer to USA measurement regulations)
Asphalt surfaces manufactured using rubber-modified bitumen have superior deformation resistance levels, high elasticity and excellent ageing properties. This ensures that road surfaces made of rubberised bitumen last considerably longer than others.
Asphalt layers made of rubber-modified bitumen can be manufactured using a high dosage of 6.5 – 8% binding agent. Through this high portion of binding agent, the asphalt surfaces receive an extremely high level of durable elasticity resistance, the ageing process is slowed and the service life span of such surfaces, substantially increased.
If “tecRoad” is used to a level of concentration equivalent to creating the comparable level of PmB quality, costs are, in general, lower.
In cases of special constructions such as noise reducing drain asphalts, “tecRoad” concentrations are mostly qualitatively higher than PmB. In such cases, use of “tecRoad” during the construction process is more expensive, but when the increased service life of the material is considered over the long term, it is more cost effective.
If the service life span of conventional surface treatments is compared to the service life span of rubber-modified SAM, the service life span of CTS Special Bitumen rubberised bitumen is 3 to 5 times longer.
The increased service life span of rubber-modified covering layers and surfaces facilitates not only the reduction of maintenance costs and therefore the reduced consumption of raw materials and energy, but will also facilitate, due to the reduced levels of road construction works,:
- A reduction in the number of accidents caused by road works diversions and
- The reduction of traffic jams and traffic delays
The negative economic impact of road works has been proven in many differing studies.
DETAILED EXPLANATIONS ON THE SUBJECTS OF:
- Cost effectiveness
- Characteristic values for binding agents
- Strength / vigorousness test
- Kantabro test and mechanical resilience
- Service life span and operational performance
- Stress performance
- Surfacing thickness levels, asphalt cover surfacing dimensions
- Surface fatigue tests