Bituminous binders

Although generally ignored in plastics literature the bituminous plastics are still of interest for specific applications. The moulding compositions consist of fibrous and mineral fillers held together by a bituminous binder together with a number of minor ingredients. 

The Shell papents broadly cover a bituminous paving composition in which the aggregate is coated with bituminous binder and the excess undissolved sulfur acts as a filler in the void spaces between the aggregate. The process is particularly adaptable for use with inexpensive, ungraded sands which are not suitable for use as an aggregate in a conventional hot mix asphalt concrete this mix class has often been called sulfur-asphalt-sand (SAS), but Shell s product is currently tradenamed THERMOPAVE. 

Generally, bituminous binders adhere well to limestones and are resistant to stripping [8.1]. Section 26.5 describes the use of hydrated lime as an anti-stripping agent. 

Bound aggregate is an aggregate which is coated and bound with a cementitious, or bituminous binder, as in bituminous macadam, or concrete. 

The Wettability of Road Aggregates with Doped Bituminous Binders... 

Hallberg [4] has shown that, from an experimental point of view, it is of interest to replace the binders by liquid hydrocarbons this eliminates viscosity, which is an interfering factor. The qualitative sense is not seriously altered, as the chemical properties of the hydrocarbons, which control the wetting phenomenon, are very closely related to the properties of the bituminous binders. 

Bitumen, bituminous binders and anti-stripping agents... 

At this stage, in order to avoid confusion, it is necessary to clarify the meaning of the terms bitumen and asphalt, as well as their adjectives bituminous and bituminous binder. The reason is that, nowadays, the above terms have different meanings, certainly among European and American specifications and practising engineers. 

According to the same specification, asphalt is a mixture of mineral aggregate and bituminous binder. 

In addition, bituminous is the adjective applicable to binders and mixtures of binders and aggregates containing bitumen. Elence, bituminous binder is the adhesive material containing bitumen. 

The bitumen and bituminous binders may be divided into three general groups (a) the paving grade bitumens, (b) the hard paving grade bitumens and (c) the oxidised bitumens. 

Source Reproduced from CEN EN 12591, Bitumen and bituminous binders - Specifications for paving grade bitumens, Brussels CEN, 2009. With permission ( CEN). 

Cut-back and fluxed bituminous binders are suitable for use in the construction and maintenance of roads, airfields and other paved areas. The bitumen used may be paving grade bitumen (in most cases) or by addition of polymer. 

The recommended classes of cut-backs and fluxed bituminous binders with the technical requirements specified by CEN EN 15322 (2013) are as shown in Table 3.9. 

Table 3.9 Specification framework for technical requirements and performance classes of cut back and fluxed bituminous binders... 

Similarly, the characterisation Fv 7 B 6 indicates a high-viscosity polymer-modified bituminous binder cut-back or fluxed material that contains a flux of vegetable origin, in which the recovered binder has a softening point higher than 50 C. 

The cohesion of stabilised binder from polymer-modified cut-back and fluxed bituminous binders, which are used for surface dressings, shall be determined in accordance with CEN EN 13588 (2008). For binders used in asphalt mixes, the test methods given in either CEN EN 13587 (2010) or CEN EN 13589 (2008) rosy be used. For binders used in other applications,any one of the three methods listed above, CEN EN 13587 (2010), CEN EN 13589 (2008) or CEN EN 13588 (2008), msy be used. 

Table 3.12 Energy requirement in the production of bituminous binders...

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