3.2.1. Pozzolanic Reactivity

Lime adsorption is an indicative measure of hydraulic/pozzolanic reactivity. The results of the lime sorption tests are shown in Table 3. Based on the Table 3, it can be stated that the SSA and CaO uptake values followed a similar trend after the mechanical activation: the increased SSA significantly increased the amount of adsorbed CaO. The lime uptake of CDW increased from the initial 126.9 mg CaO/g solid material to 192.1 mg CaO/g solid material. Thus, as a result of a 33% increase in SSA, the CaO uptake increased by over 50%.

**Table 3.** Lime adsorption of CDWs.


Figure 2 illustrates the volume change (swelling) during the reaction between CDW and lime. It can be clearly seen that the ground CDWs had a larger volume than the original at the end of the lime sorption test (after 30 days), indicating a greater degree of reactivity.

**Figure 2.** CDW samples after the lime sorption test (from left to right: 0 min, 1 min, 3 min, 5 min and 10 min).
