Abstract: Methods and devices for improved measurement of the thermal expansion and/or chemical reactivity of aggregates used in concrete and for similar substances. Aggregate is placed into the chamber of a metallic container having an enlarged opening. The aggregate is placed in a water bath, and a tightly sealable lid is placed onto the container. The lid carries a linear variable differential transducer (LVDT). A thermocouple for sensing temperature is also retained within the lid so that a sensor on the thermocouple contacts the water bath when the lid is secured onto the container. The LVDT is operationally interconnected with a storage or recording device. In a preferred construction the lid retains a tower member having a float that is freely moveably mounted upon a guide rod. Movement of the float is indicative of a volumetric change in the aggregate and water.

Abstract: Methods and devices for improved measurement of the thermal expansion and/or chemical reactivity of aggregates used in concrete and for similar substances. Aggregate is placed into the chamber of a metallic container having an enlarged opening. The aggregate is placed in a water bath, and a tightly sealable lid is placed onto the container. The lid carries a linear variable differential transducer (LVDT). A thermocouple for sensing temperature is also retained within the lid so that a sensor on the thermocouple contacts the water bath when the lid is secured onto the container. The LVDT is operationally interconnected with a storage or recording device. In a preferred construction the lid retains a tower member having a float that is freely moveably mounted upon a guide rod. Movement of the float is indicative of a volumetric change in the aggregate and water.