Construction dictionary

Aggregate and ballast recycling

Aggregates making up the granular layers which form part of civil engineering infrastructures were traditionally extracted from quarries and pits with very negative environmental impacts. Because of t...

Catenary

This is a group of conductor cables from which the engine gets its electrical energy by means of pantographs. Basically, the catenary is made from a carrying cable and one or two contact wires joined ...

CBR test

This test serves to measure the platform's support capacity that is its deformation resistance under loads. In a standardised procedure, the platform delivery on site conditions are brought nearer by ...

Clearing ballast from the track

This consists in removing part of or all the ballast for its purification and reuse or for its removal or substitution, whatever the case, the splice bars' settling bed must be destroyed to reach a ce...

Continuous welded rail

These are long rail bars welded in a workshop and transported in especially equipped wagons to the location where they are to be laid. Once positioned on the splice bars, these rail sections are welde...

Deval test

This test measures the aggregate's resistance to abrasion. In a standardised procedure, pre-set granulometric fractions of ballast or gravel are introduced into two slanted axis rotary cylinders (one ...

Geosynthetics

These are materials manufactured with polymers (mainly polypropylene but also polyester, polyethylene and others) whose use implies technical and economical improvements in transport infrastructure's ...

Geotextiles

These are continuous or short fibre geosynthetic materials, mainly prepared in the form of woven or un-woven sheets, for their use as an auxiliary element between the infrastructure's platform layers....

Guideway envelope

This is the shape of the track on the ground and on which the railway is settled. Its layers are of a standard composition, resistance and dimensions depending on various parameters: ground (embankmen...

High-speed railway

These are rails designed and built for commercial speeds of 250-350 km/h, to which new elements have been incorporated to the traditional technology on the track as well as in the tractive and trailin...