Deterioration of stone materials in the Angkor monuments, Cambodia

The Angkor monuments in Cambodia are built mainly of sandstone and laterite. This paper mainly describes the deterioration of sandstone blocks. The sandstone in the monuments can be classified into three types based on the colour, texture, chemical composition and constituent mineral; grey to yellowish brown sandstone, red sandstone and greenish greywacke. The deterioration is distinct in grey to yellowish brown sandstone because of its low compressive strength, high porosity, well developed bedding, and constituent minerals susceptible to alteration such as feldspar and biotite. The main causes of deterioration identified are chemical weathering, efflorescence related to bat guano, and biodeterioration by the growth of trees, algae and lichens. An water supply is also indispensable for deterioration.