PSI - Issue 70

Sreegovind M. et al. / Procedia Structural Integrity 70 (2025) 556–563

560

30

0 0.05 0.1 0.15 0.2 0.25 0.3 0.35

25

20

10 (N/mm 2 ) 15

(W/m.K)

5

Compressive strength

Thermal conductivity

0

CM CM-5 CM-10 CM-15

CM CM-5 CM-10 CM-15

Mixes

Mixes

Fig. 5. Variation in compressive strength

Fig. 6. Variation in thermal conductivity

4.3 Modelling Understanding the heat transfer across the material is a major part in the assessment of thermal insulation. In the current study, to assess the thermal performance of the developed mortar, a cement mortar slab with the dimensions 0.4 × 0.3 × 0.02 m is modelled in COMSOL Multiphysics software. The slab is prepared using both normal mortar (CM) and vermiculate incorporated mortar (CM-15) to examine the impact of EV inclusion in the mortar. The modelled slab is given in the fig. 7.

Fig. 7. Slab used for simulation

Figures 8 and 9 depict the temperature distribution within the control mortar (CM) and the mortar incorporated with vermiculite (CM-15), respectively, over three time periods: 0 hours, 12 hours, and 24 hours. At the start (0 hours), both slabs demonstrate a consistent temperature of approximately 293 K, indicating that their initial conditions are the same. After 12 hours of simulated thermal exposure, with the external surface temperature set at 323 K, the CM-15 slab exhibits less heat penetration compared to the control slab, highlighting the insulating properties of vermiculite. The internal temperature of the CM-15 slab remains significantly lower, especially in the bottom layers, attributable to its reduced thermal conductivity. After 24 hours, when the external temperature falls back to 293 K, the CM-15 slab shows improved cooling efficiency in contrast to the control slab, which continues to hold higher thermal energy. These findings validate that the addition of expanded vermiculite notably improves the thermal resistance of cement mortar, effectively minimizing heat retention and facilitating quicker cooling under varying thermal conditions.