3. Results and discussion
3.1. Leakage of PCM
The nonmodified PX25–cement mixture after mixing is shown in Fig. 5.
The exuded liquid from the nonmodified PX25 was found to segregate on top of the mixture. After initial hardening of the
mixture, the paraffin was poured out and placed in a room at 20 C (which was lower than the melting point of PX25) for 24 h.
The liquid mixture solidified completely and no extra liquid was found in the mixture after 24 h cooling.
Thus we concluded that the exuded liquid mixture was 100% paraffin.
The leakage ratios (defined as the mass fraction of the exuded paraffin to the total paraffin contained in the PX25) were calculated and are given in Table 3.