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Climate Change and Its Impacts On Monuments And Building Structure

by | 03-11-2012 10:18




Introduction

The result of  rapid  urbanization, industrialization  made in  the  name  of  development has  created  a number of   disastrous  consequences  in front of us. These  disasters appears  among us sometimes as pollution, sometime acid rain and now Climate change as the summation of all these  environmental hazards,  producing vast alternation in the environmental and natural  phenomena. Climate change, a big environmental threat and challenge of our generation has created several signals of disturbances in different aspects of life present in this planet. Climate change, result of immoral deeds of human is  presenting its  pressure  to  human  and  other forms of life equally although merely  human actions  are responsible  for inviting climate change. Thousands of green writer describes this menace using different languages keeping the  central  theme  same. Their discoveries and opinion about climate change and its impacts can be read  in   newspapers, books, online magazines etc. However this paper is presenting a fresh but relevant topic which is the impact of climate change on monuments and building structures.

Along  with  the speedy industrialization and  urbanization, people  are  spending heap of coins for the construction purpose which  involves  the  construction of  buildings, monuments, bridges, culverts, roads, etc .These  structures  are  erected taking the  local  environment and temperature under consideration. These structures should match the local environmental condition otherwise it results into failure. Because of these reasons different types of construction can be witnessed in   the  different  geographical regions of varying   environmental  factors. We   see different figures of constructions if we visit different places but almost same type of constructions in a same area.

Causes of monuments and building Deterioration

In this era , climate  change( global  warming)  has  emerged  as  a  global  environmental  threat. So  there  is  no  any   surprise  that  scientists  would be interested to understand  how climate change  impacts on concrete  from  which   our  infrastructures  are  made.

Concrete deterioration occurs by variety of stimuli including physical, chemical and mechanical factors. Among  the  various ,the major two cause  of  deterioration  are  carbonation  and  chloride  penetration. Carbonation occurs when atmospheric CO2  penetrates the  concrete structures  and  exposes    steel  reinforcement (makes  the  attachment of  concrete and rod more  fragile)

.Similarly, chloride penetration causes cracking and peeling of various layers of these structures.

 However the time for corrosion depends on their location and level of exposure to the environment. Durability of concrete structures depends heavily on the  manner   in  which  they  are  constructed, material  used  as  well  as  the  environmental  condition  they  are  routinely  exposed  to.

 
Similarly, climate change also badly affects our historical, cultural heritage, which were specially made up of  natural  stones. In the present situation, we all are familiar with the increasing global temperature which rapidly heats the  outer layers of these monument building?s  stones(non conductors)  while  the  inner  layers  of  the  same  stone  is  heated  very  slowly. Due  to  this  vast  temperature  difference ,unequal  expansion   and  contraction  among  the  various  layers  of  stone results  in  peeling  of  stone, cracking of  it  resulting  in  pore  formation   and  finally  leads  to  the  damage  of  monument. This  process  is  heavily  supported  by  the  temperature  difference  observed  in  day to  night, summer  to  winter .This  increasing  temperature   may  cause  high  dryness  in  the  stone  and  alters  the  chemical  composition  of  the  stone  making  it  more  fragile and brittle .This  dryness  may  result  in  conversion  of  gypsum  to  anhydrite  as  follows,

 

   CaSO4.2H2O      into                         CaSO4+H2O             

   Due to raise in percentage of CO2  in  atmosphere, CO2  gets  transformed  into  carbonic  acid(H2CO3)   when it comes in contact  with atmospheric  moisture. Thereafter, carbonic acid thus formed interacts with basic mineral components of stones and transforms them into soluble salts leading to damage of stone structures. Both of these corrosion mechanisms are influenced by climate change.  

The story doesn?t ends here. Due to climate change mutable  wind  pattern  is often  seen .High  air  speed  is  often  observed,  large  dust  particles  including  sand  particles   are  blown  and  acts  like  a  mobile Saw  and  erodes   monument  and their  surface.

 Also the  amount  of atmospheric   SO2   is  increasing  due  to  increasing  traffic  intensity , industrial  activities, etc. Conversion of SO2 into SO3  takes places when water  vapor  acts  upon  SO2. and H2SO4    is  formed  as  the  final  product. This  final  product  acts  upon  salt  component  of  stone  and  changes  into  calcium  sulphate.

Likewise, Sulphur  dioxide(SO2)and  Nitrogen  dioxide(NO2   )   are  produced  during  the combustion  of  fossil  fuel  as  gas,coal,oil  for  power  generation. Nitrogen  dioxide(NO2) in  the  presence  of  water  converts  into  nitric  acid  which  transforms  calcium  carbonate  present  in  stone  and  rocks    into  calcium  nitrite.

Similarly, artificial  aerosols  which  consists  of  fine  carbonate  particles, organic  compounds  as  hydrocarbon, aldehyde, tars deposits  on  the  surface  of  monuments and makes the  outer appearance  of  the  monuments/building  black  that  looks  ugly. This  is  often  seen  in  old  religious  and  cultural  heritages  of  Nepal and India also.

The  live  example  of  it  can  be  found  in  Taj  Mahal  which  is  recorded  to  be  badly  affected  by  so2. Similarly  ,Giza,  where  most  important  Egyptian  monuments and  historical  places  are  found  are  also  noted  to  be  suffering  from  these  adverse  climatic  factors.

Conclusion

Monuments  are  the  treasure  of  every  nation  and  the  protection  of  them  is  the  responsibility  of  every  wise  citizens. These  wealth  transfers  the  information  of ancient  life  styles, culture, religion  to  the  future  generation. So we must  be  aware  about  the  monument  deterioration.

Due  to  this  climate  change  it  is  sure  to  raise  the  cost  of  building  and  monument  construction . One  has  to  spend  more  for  making  a  better  home  which  suits  the  rapidly  changing  climatic  factors .Above  mentioned  facts  proves  that  the  prevailing  construction  materials  are  less  durable  for  the  future  if  the  climate  changes  in  same  pattern.

References 

1) Research report  of  CSIRO   climate  change  flagship  Australia.

2) Wikipedia

3)S.M.Robaa/ICEHM 200,Cairouniversity,Egypt,September,2000.Pase 187-200