Hydraulic road binders

A variety of binders are used for road bases and sub-bases, capping layers, soil stabilisation and soil improvement, depending on the availability of materials and local traditions. This section refers to factory blended mixtures of binders. In-situ treatment of materials, using lime and other binders is described in section 26.3. 

A European Standard for factory blended hydraulic road binders is in preparation [26.20]. Current proposals for permitted constituents are listed in Table 26.3. 

Major Portland cement clinker Granulated blastfurnace slag Natural pozzolanas Thermally activated clays and shales Siliceous fly ash Calcareous fly ash Unslaked calcareous fly ash Burnt shale Limestone Limes 

Minor as specified, up to 5% Calcium sulfate (gypsum, hemihydrate, or anhydrite) 

Lime used in hydraulic road binders should conform to EN 459-1 [26.18]. 

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Hydraulic road binders 28.2 Boiler feed water... 

Table 263. Draft list of permitted constituents of hydraulic road binders...

EN XXX Hydraulic road binders — Composition, specifications, and conformity criteria (in preparation). 

The hydraulic binders or constituents such as cement, fly ash, slags and lime should comply with CEN EN 197-1 (2011), CEN EN 14227-4 (2013), CEN EN 14227-2 (2013) and CEN EN 14227-11 (2006), respectively. Additionally, any other hydraulic road binder, that is, factory-blended hydraulic binder for road use, may also be used, provided it complies to CEN EN 12447-5. 

The same applies with the aggregate gradings for the other HBMs such as slag bound mixtures (SBM), fly ash bound mixtures (FABM) and hydraulic road binder bound mixtures (HRBBM). They should fall within the grading envelopes specified by GEN EN 14227-2 (2013) for SBM, CEN EN 14227-3 (2013) for FABM and CEN EN 14227-5 (2013) for HRBBM. 

The soil requirements when treated by hydraulic binder are specified in the appropriate specification depending on the binder used CEN EN 14227-10 (2006) for soil treated by cement, CEN EN 14227-11 (2006) for soil treated by lime, CEN EN 14227-12 (2006) for soil treated by slag, CEN EN 14227-14 (2006) for soil treated by fly ash and CEN EN 14227-13 (2006) for soil treated by hydraulic road binder. 

CEN EN 14227-5. 2013. Hydraulically bound mixtures - Specification - Part 5 Hydraulic road binder bound mixtures. Brussels CEN. 

CEN EN 14227-13. 2006. Hydraulically bound mixtures - Specifications - Part 13 Soil treated by hydraulic road binder. Brussels CEN. 

The materials for the base and sub-base course are unbound aggregate mixtures or hydraulically bound aggregate mixtures. The aggregates may be crushed granular materials, manufactured materials from rock deposits or industrial by-products (slags) or recycled materials. The hydraulic binders, in the case of bound materials, are cement, fly ash, slag, lime, a mixture of some of them or factory-blended hydraulic binders for road use. 

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