What is Buoyancy Effect of TGA experiment?
TGA (thermogravimetric analysis) is an important method to analyze the hydration products of cementitious materials. When a TGA test for cementitious materials sample is performed, the initial TGA curve may appears as such:
As material researchers, we know density is the physical property of materials. Even since grade school, we are taught that density is simply the mass of an object divided by its volume.
However, this is pretty complicated in the case of cementitious materials. The mass of a certain amount of harden cement (or concrete) paste is a finite value, but how about the volume? since the harden cement paste is porous, how do we consider the open and close pores inside the paste as we want to determine the volume?
As reported by China Daily, the official Chinese newspaper in English, China’s cement output growth drops sharply in the first five months. The output grew 5 percent from a year earlier to 793.98 million tons; however, the growth rate represented a sharp decrease of 14.3 percentage points from the same period of last year, showed by the National Development and Research Commission.