Important Raw Material—Coarse Aggregate - The Issues and Discussion of Modern Concrete Science - page 28

would turn into marble after a long-term evolution, as shown in Fig. 2.6 . The case is
similar to granite. Granite is formed under the ground when volcano is erupting, and
it will turn into gneiss after a long-term evolution, as shown in Fig. 2.7 . Gneiss is
more widely distributed in China. Foundation of the Three Gorges Dam is on
gneiss. Any rocks that exposed to air will turn into soil after long-term weathering
and corrosion. The soil will turn into sedimentary rocks back again after a long-term
evolution. That is why soil in Northeast of China is entirely black, while it is all red
in Southern China. This due principally to the rock exposed to local earth

s surface.
Based on engineering experiences obtained in more than 20 different provinces
and cities, rocks exposed to the earth

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s surface are mostly granite and limestone,
secondly is basalt. Andesite and diabase distribute more in local areas. Rock in
northeast area is mainly basalt and andesite; Xinjiang area is mainly basalt; Haikou
in Hainan Island is mainly basalt; Sanya area is mainly granite; Shanghai, Zhejiang,
Hangzhou, and Ningbo areas utilize tuff more commonly; Shanxi, Shanxi, Henan,
Hubei, and many southern areas are mainly limestone; and many parts in Inner
Mongolia (especially in eastern areas) are mainly diabase.

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Fig. 2.6 Marble

Fig. 2.7 Gneiss