Glossary

 
 

A

Aggregates

Aggregates are small rock fragments (0.08 to 80 mm) of mineral origin. Aggregates come in different types: maritime, fluvial and terrestrial. They may be sand, gravel or crushed gravel. Aggregates, mixed with water and cement, are essential for the production of concrete.

C

C02

Carbon dioxide (CO2) is a greenhouse gas. It is produced by the combustion of organic compounds and the respiratory systems of animals and plants.

The cement industry naturally emits CO2:

  • 60% of emissions are due to the physical-chemical transformation of raw materials at high temperatures,
  • 40% result from the combustion needed to heat the cement furnace to 1500°C.
Cement

Cement is a hydraulic bonding agent which is obtained by heating, then grinding, a mixture of limestone and clay. Most cements are made from clinker and additives and are usually used in the form of a powder. Cement sets when mixed with water. Combined with sand and aggregates (sand or gravel), it turns into rock-hard concrete or mortar.blabla

Clinker

Clinker is the main ingredient in cement. These hardened granules are obtained by firing a mixture of approximately 80% limestone and 20% clay to a high temperature. Cement is obtained by grinding clinker and, in some cases, supplementing it with additives.

Concrete

Concrete is a building material made by mixing water, aggregates and sand with a binding agent (usually cement) and, if necessary, with additives. This mixture is made on building sites and factories.

The characteristics of a concrete can vary greatly depending on the choice of cement and cement-aggregate ratio, the type of aggregate used, the inclusion of additives, etc. The way concretes are used and surface treated can also have an impact on their performance and appearance. So concrete is reconstituted stone and is sometimes referred to as "liquid stone".

Crushed gravel

Crushed gravel is produced by crushing hard rock. These gravel samples measure from 5 to 25 mm.

Crushed gravel is used as an aggregate during concrete manufacture and as a paving base for road surfaces.

D

Ductility

Ductility refers to a material's capacity to be stretched or bent without breaking. A material which does not have this quality is fragile.

F

Filler

An inert, finely ground mineral material that is included in paints and hydraulic binders (cement) to reduce costs and, in some cases, modify their physical characteristics. In this respect, they are considered to be a cement additive.

Fly ash

Fly ash is hydrophilic and can be used as a cementitious additive. The ash, which is collected from chimney filters in coal-fired power plants, is composed of vitreous silica, alumina, iron oxide and lime.

They can be used as a partial substitute for clinker and thus help to reduce CO2 emissions.

Foundation

The foundations of structure distribute its weight and ensure its stability. They are made of poured concrete. The design of foundations must allow them to bear the weight of the construction and prevent any vertical or lateral shifting.

H

Hydraulicity

Hydraulicity is the extent to which a material hardens in the presence of water

J

Joint

A joint is the filling or sealing of a gap between two construction elements or a continuous rectilinear separation in a construction, designed to absorb differences in the movement or behavior of 2 adjacent elements.

L

Lime

Lime is a binding agent obtained from the calcination of limestone. Limes are divided into 2 categories depending on whether they are set by exposure to carbon dioxide (slaked lime) or to water (hydraulic lime).

Slaked lime is mainly used in traditional finishing plasters, pointing mortars and whitewashes. Hydraulic lime contains clay, giving it similar properties to cement and making it suitable for use as an undercoat or render

P

Portland

The name ‘Portland' comes from a peninsula in Great Britain.

The gray stone of this area has a composition and appearance similar to that of cement. Portland cement is the generic name of basic, highly-efficient hydraulic cements. They are obtained by grinding clinker, which is made from firing a carefully-composed mixture of limestone, silica, alumina and, in some cases, other products.

Pozzolan

Pozzolan is named after Pozzouli, a region near Naples, Italy, which is rich in volcanic ash.

Natural pozzolan is a light siliceous mineral produced during basaltic volcanic eruptions. It contains silica, alumina and iron oxide (which gives it a red color), as well as lime and magnesium oxide. Pozzolan is used as a cement additive.

Artificial pozzolans with the same properties as natural pozzolans can be created by heating clays, basalts or schists.

R

Raw mix

Raw mix is made of finely ground rock thinned with water. It is dosed and homogenized before being put into a kiln to make cement

Rehabilitation

In construction, rehabilitation refers to the renovation of a building which is dilapidated or no longer in compliance with safety standards.

Reinforced concrete

Cement concrete is very resistant to compression but it is less resistant to tensile stress and bending. Steel, on the other hand, is very flexible thanks to its high tensile strength.

Reinforced concrete takes advantage of their different properties by combining steel and concrete to produce a material with high compressive and tensile resistance

S

Silica fume

This by-product of the silicon industry results when quartz is heated to high temperatures. Silica fume - dust particles which measure only 0.2 micrometers - is collected by electro-filters for use as a cement admixture

Slag

This mixture of lime, alumina and silica is produced when iron is smelted with coke in blast furnaces in the steel industry. Slag accumulates on top of the molten cast iron. If cooled quickly, its hydraulic properties are close to those of clinker. Slag takes longer to hydrate but it offers greater stability in corrosive conditions. It is, therefore, a suitable additive for cement and concrete so as to reduce CO2 emissions.

Sustainable construction

Sustainable construction aims to limit the impact of buildings on the environment while enhancing their quality in terms of aesthetics, sustainability, durability and strength. Sustainable construction techniques apply across the entire lifecycle of a building, from the selection of initial materials to demolition and recycling.

Sustainable construction signifies in particular:

  • the use of recyclable materials to conserve natural resources,
  • the integration of renewable energy sources into a building's design,
  • the optimization of renewable energy sources.