Testing and Performance Criteria for Stabilized/Solidified Waste Forms - Stabilization and Solidification of Hazardous, Radioactive, and Mixed Wastes - page 292

11.4.9 M OISTURE C ONDITION V ALUE (MCV)

MCV 69,70 is a measure of the compactibility of a soil for use in earthworks. It involves
repeatedly dropping a rammer onto a loosely packed sample and measuring the
resulting penetration. The MCV is then obtained from a plot of 'change in penetra-
tion' versus 'log of number of blows.' It is used as an acceptance test for soils that
are to be stabilized with lime or cement. The advantage of MCV as a quality control
test is that an instant result is available, whereas it would take longer to obtain a
value for the moisture content. It is particularly useful for cohesive material.

11.4.10 D RY D ENSITY /M OISTURE C ONTENT R ELATION

Dry density/moisture content relation 58,71 is a test often used when materials are to
be used for earthwork purposes. It involves the compaction of a moist sample at
different moisture contents. This is particularly useful for granular materials, while
MCV as mentioned above is often used for cohesive materials.

11.4.11 S LUMP

Slump 72-74 is one of several tests that could be conducted to obtain a measure of the
workability of a material. The test involves the measurement of the decrease in
height of the peak of a cone of freshly mixed material, after removal of the standard
cone-shaped mold.

11.4.12 F LOW

Flow 31,75-77 is another of several possible tests to measure material workability. These
tests involve the measurement of the resulting spread of the freshly mixed material,
after removal of a standard mold.

11.4.13 S ETTING T IMES

Initial and final setting times 35,78-80 can be determined by the penetration of a needle
into the hydrating sample to observe the early stiffening of a paste prior to strength
development. Setting time can also be determined from the heat evolution curve, or
by monitoring electrical conductivity or ultrasonic pulse velocity. This property is
important for determining the time available for placement of a material and is useful
to identify the effects of different contaminants and binders on hydration.

11.4.14 H EAT OF H YDRATION

The heat of hydration 81,82 is the amount of heat evolved upon complete hydration in
a calorimeter, at constant temperature, or under adiabatic conditions. 55 The heat of
hydration of an S/S material mix can be compared with the heat of hydration of the
binder system to assess the relative degree of hydration.