Approach and evaluation of measuring methods on the content of free calcium oxide in cement clinkers;

By using scanning electron microscope(SEM) the hydrate of highly free calcium oxide(f CaO)cements is studied,and the distribution and crystalline characteristics of calcium hydroxide in cement are investigated and the different boundary characteristics between calcium hydroxide with CSH at early hydration stage and later stage as well.

and the rescarch results of the expansion of free calcium oxide in steel slag after chemical reaction which is the biggest problem in steel slag application worried about by road engineers, the construction technological specification of the application of graded steel slag mixture as pavement base materials was developed.

However,the free lime content of the fly ash is higher.

Hydration of free lime often leads to a volumetric expansion of hardened cement pastes.

The effects of various mineral additives such as fly ash, blast furnace slag and silica fume on the action of free lime in cement, and the mechanism of their effects on the cement soundness and expansion behaviors of HCP have been studied and discussed.

The main cause leading to the disqualification of cement soundness in hardened concrete is excessive f-CaO or magnesia in the cement mixture.

In the cement production process it is hard to develop an accurate mathematical model for both f-CaO and stack bed thickness which characterize the key technical indices in the cooling process with a grate cooler.

In this paper, the hydration kinetic process of free CaO in system containing high calcium fly ashH 2O has been studied under different temperatures.

Results show that the crush value,free-CaO content,invariability and innocuousness of the slag are all in conformity to the national standards and related trade criterion when the slag is put in storage for 12 months.