Ciment et Architecture

Glossary

Additive

Product added to the mortar in small quantities (less than 5% of the mass of cement) to modify the properties of mortars or concretes, either when wet (such as Tempo, which is the  Prompt natural cement setting retarding agent) or after hardening.

Alteration

An alteration refers to an accidental or natural change that occurs to a cultural asset. The term describes both the process and the result.

Concrete

The modern definition is construction material formed of a mixture of hydraulic binders, granulates and water, possibly with additives. This mixture is applied in its plastic state and then progressively dries to form a monolith.

Cornice outline

The surround for mouldings and, by extension, all moulded ornaments.

Cultural asset

A cultural asset is an object to which society attributes a particular aesthetic, historical, documentary, scientific, social or religious value (or even a combination thereof). The material cultural heritage is constituted of all mobile (transportable) and immobile (immovable) cultural assets.

Grinding

Reduction to powder or very fine specks.
Grinding can be done:
- by milling (minerals),
- by crushing (colouring agents, cement)
- by crumbling (waste). re usually equipped with a grinding device or equipment and a separator that returns materials and substances that are too large back to the grinder, along with all dust particles resulting from ventilation. 

Grout

Pure cement render of liquid or creamy appearance, applied to walls using a long-haired brush to increase the bonding of subsequently-applied mortar.

Mortar

Mixture of water, sand and a binding agent.

Moulding

Continuous hollow or embossed profile in stone or mortar, particularly popular in moulded cement ornamentation of the 19th century.

Natural cement

Cements obtained by firing argillaceous or marl limestone containing 23-30% clay. Normal limestone contains 23-24% clay. 

Non-hydraulic lime

Lime has the characteristic of setting in the open air in reaction to carbon dioxide. This is also known as slaked lime, because of its characteristics of plasticity and smoothness. Its modern name is calcic lime.

Patina

Highly diluted lime milk, used for its transparent effect.

PNC

Abbreviation for Prompt natural cement.

Prompt natural cement whitewash

Prompt natural cement milk applied to renders, mortars or concrete to colour and/or protect them.

Render

Coating comprised of one or more layers of a plastic material used for the protection (water, insulation, etc.) and presentation of the structure it covers. It is applied in three stages: roughcast or base coat, filling (Floating coat) and rubbed finish.

Repointing

Repairing of joints with a cement mortar. Joints can be hollow or embossed, although hollow joints better protect masonry against water infiltration.

Restoration

Restoration is direct action undertaken not only to improve the condition, knowledge and understanding of a cultural asset, but also to exhibit, use and understand it. It is undertaken only when the asset has lost some of its meaning or its function because of alterations or past reorganisations which prevent understanding and/or interpretation.

Roman cement

The commercial name of natural cement invented in England by Parker at the end of the 18th century. Roman cement was the term used for all hydraulic products resulting from very argillaceous limestones that were subject to moderate temperature and mechanically pulverized.

Roughcast or base cast

First coat of a render whose primary role is to ensure bonding to the surface.

Sand

Granulate graded under 5 mm, resulting from the disintegration of mineral rock or from its mechanical crushing. In terms of weight it is the major constituent of mortars and concretes.

Setting accelerator

Additive for concrete or mortars that is put in the mixing mortar to reduce setting time by accelerating hydration of the cement.
In cement works, grinding workshops generally comprise a grinding machine, a separator –which allows the bigger pieces to be returned to the grinder – and a de-dusting and ventilation assembly.