Experimental investigation on mechanical properties of a volcanic ash with different grain size gradations

By means of contrast and research the eight seams' tonsteins characteristics of the petrography,mineralogy and geochemistry,it can be confirmed that all the tonsteins are the alkalinityvolcanic ash derived tonsteins from different age.

Ten out of thirteen MS peak layers,which are thicker than 4 cm,correlate well with the volcanic ash layers recognized in core MD972142 offshore northwest.

New information on the response of vegetation to air-fall volcanic ash is provided by analysis of phytoliths from sediments containing major tephra beds.

The tephra could not comprise ash layer in the sediments; however, they were dispersed in the same depth of the core, which is located in 27.

8 kaBP,which was recognized as the K-Ah tephra derived from Kikai volcano in southern Japan.

Feasibility of using Tibet s pozzolan as mineral admixture of concrete;

In order to explore main causes and dynamic mechanisms, the latest data of past sequences of solar radiation and volcanic dust are adopted in this paper to simulate the climate change during the Little Ice Age.

Based on the Longjiang water conservancy project in Yun-nan, performances of concrete using four materials plans including moderate heat Portland cement, ordinary Portland cement, pozzolana and limestone powder are studied, further more their costs are contrasted.