Circular Cement Expansion Mold

Circular cement expansion mold is a kind of test instrument only used to measure the linear volume shrinkage or expansion performance of cement system. The purpose of this test method is to use circular cement expansion mold to measure the linear volume shrinkage and expansion of cement slurry under atmospheric water bath condition.

Cement expansion depends on the amount of expansion agent, cement fineness, cement slurry design and curing conditions (pressure, temperature, time, etc.). The amount of expansion is greatly affected by the boundary conditions. The chemical process of mineral growth depends largely on the stress state, and mineral growth tends to occur at the lowest stress values, such as in the pores or at the edges. Thus, the extent to which the cement shrinkates or expands depends on a range of environmental conditions, all of which cannot be clearly defined in the test. This test method does not fully represent the condition of well bore annulus.

The mold is made of corrosion resistant materials (such as stainless steel). The OD of the inner ring of the mold is 50.8mm. The ID of the inner ring of the mold is 44.8mm, and the ID of the external expansion ring is 88.9mm (see Figure

The elasticity of the mold outer ring should be calibrated once a year. During elastic calibration, after applying a force of 1000g±1g on the mold, the distance between the two measuring steel balls should be increased by 2 mm±0.3mm without permanent deformation (see Figure ).