Mundic
Encyclopedia
Mundic was used from the 1690s to describe a copper ore, which began to be smelted at Bristol
and elsewhere in southwestern Britain
. Smelting
was carried out in cupolas, that is reverberatory furnace
s using mineral coal
. For more details, see copper extraction
.
Mundic once referred to Pyrite
, but has now adopted the wider meaning of concrete deterioration caused by oxidisation of pyrites within the aggregate (usually originating from mine waste). The action of water and oxygen on pyrite forms sulphate (a salt of sulphiric acid), thereby depleting the pyrite, causing loss of adhesion and physical expansion.
word mundic is now used to describe a cause of deterioration in concrete
due to the decomposition of mineral constituents within the aggregate. A typical source of such aggregates is metalliferous mine waste. Current professional guidance notes describe all of Cornwall
and an area within 15km of Tavistock as being areas where routine testing for mundic is required. The notes go on to state that testing should be confined to buildings which contain concrete elements (blocks or insitu) and that were built in or prior to 1950. However, the notes contain advice that testing may be required where there are visual or other signs of mundic decay. Testing leads to a classification of A, A/B, B and C. A is sound, A/B is sound (but may require re-inspection at a later date) and C is unsound. Classifications B & C mean that a property may be un-mortgagable.
Typically a house is routinely screened if constructed between 1900 and 1950 from concrete block .
Bristol
Bristol is a city, unitary authority area and ceremonial county in South West England, with an estimated population of 433,100 for the unitary authority in 2009, and a surrounding Larger Urban Zone with an estimated 1,070,000 residents in 2007...
and elsewhere in southwestern Britain
Early Modern Britain
Early modern Britain is the history of the island of Great Britain, roughly corresponding to the 16th, 17th, and 18th centuries. Major historical events in Early Modern British history include the English Renaissance, the English Reformation and Scottish Reformation, the English Civil War, the...
. Smelting
Smelting
Smelting is a form of extractive metallurgy; its main use is to produce a metal from its ore. This includes iron extraction from iron ore, and copper extraction and other base metals from their ores...
was carried out in cupolas, that is reverberatory furnace
Reverberatory furnace
A reverberatory furnace is a metallurgical or process furnace that isolates the material being processed from contact with the fuel, but not from contact with combustion gases...
s using mineral coal
Coal
Coal is a combustible black or brownish-black sedimentary rock usually occurring in rock strata in layers or veins called coal beds or coal seams. The harder forms, such as anthracite coal, can be regarded as metamorphic rock because of later exposure to elevated temperature and pressure...
. For more details, see copper extraction
Copper extraction
Copper extraction techniques refers to the methods for obtaining copper from its ores. This conversion consists of a series of chemical, physical, and electrochemical processes. Methods have evolved and vary with country depending on the ore source, local environmental regulations, and other...
.
Mundic once referred to Pyrite
Pyrite
The mineral pyrite, or iron pyrite, is an iron sulfide with the formula FeS2. This mineral's metallic luster and pale-to-normal, brass-yellow hue have earned it the nickname fool's gold because of its resemblance to gold...
, but has now adopted the wider meaning of concrete deterioration caused by oxidisation of pyrites within the aggregate (usually originating from mine waste). The action of water and oxygen on pyrite forms sulphate (a salt of sulphiric acid), thereby depleting the pyrite, causing loss of adhesion and physical expansion.
Mundic block problem
The CornishCornish language
Cornish is a Brythonic Celtic language and a recognised minority language of the United Kingdom. Along with Welsh and Breton, it is directly descended from the ancient British language spoken throughout much of Britain before the English language came to dominate...
word mundic is now used to describe a cause of deterioration in concrete
Concrete
Concrete is a composite construction material, composed of cement and other cementitious materials such as fly ash and slag cement, aggregate , water and chemical admixtures.The word concrete comes from the Latin word...
due to the decomposition of mineral constituents within the aggregate. A typical source of such aggregates is metalliferous mine waste. Current professional guidance notes describe all of Cornwall
Cornwall
Cornwall is a unitary authority and ceremonial county of England, within the United Kingdom. It is bordered to the north and west by the Celtic Sea, to the south by the English Channel, and to the east by the county of Devon, over the River Tamar. Cornwall has a population of , and covers an area of...
and an area within 15km of Tavistock as being areas where routine testing for mundic is required. The notes go on to state that testing should be confined to buildings which contain concrete elements (blocks or insitu) and that were built in or prior to 1950. However, the notes contain advice that testing may be required where there are visual or other signs of mundic decay. Testing leads to a classification of A, A/B, B and C. A is sound, A/B is sound (but may require re-inspection at a later date) and C is unsound. Classifications B & C mean that a property may be un-mortgagable.
Typically a house is routinely screened if constructed between 1900 and 1950 from concrete block .