Abstracts Book - IMRC 2018

• SC2-O024
DEVELOPMENT OF PHASE CHANGE MATERIALS FOR
IMPREGNATION IN COARSE AGGREGATES
Daniel Jimenez 1 , Lilia Narvaez 2 , Juana María Miranda 2
1 Universidad Autónoma de San Luis Potosí, DICIM, Mexico. 2 Universidad Autónoma de San Luis
Potosí, Facultad del Habitat, Mexico.
The use of Phase Change Materials (PCM) in construction have provided
effective solutions for the control of internal micro-climate in buildings around
the world. PCMs are those that pass the liquid to the solid state and vice versa,
during the solidification process, the material transfers energy to its
surroundings, releasing the latent heat accumulated in the fusion process. The
aim is developed a PCM based on coconut oil and paraffin to be impregnated in
porous materials. Mixtures of coconut oil and paraffin were made in proportions
(coconut/paraffin) 100/0, 98/2, 97/3, 96/4 and 95/5, evaluating their melting
points searching for temperatures close to the human thermal comfort zone. As
porous materials, pumice stones the central region of Mexico and the recycling
of concrete blocks were used as coarse aggregates, the density, pore volume
and absorption were evaluated, determining the maximum impregnation
capacity of the stones. The impregnation tests of the pebbles whit PCM were
performed under the vacuum method at temperature of 90ºC for 20, 40, 60 and
80 minutes, with a pressure of 1,000 Pa, evaluating the impregnation capacity in
the coarse aggregates. It is observed that coconut oil and coconut/paraffin
mixtures 98/2, 97/3 and 96/4 have melting points between 24ºC and 32ºC
suitable for the research. The absorption capacity of the pumice stone is high
with averages greater than 150% gain in weight; the concrete block only has a
maximum absorption capacity of 11%. Vacuum impregnation for 40 minutes
turned out to be the adequate time to reach the maximum absorption capacity
of the PCM in the coarse aggregates, obtaining impregnation of 125% for the
pumice stone and 10.5% for the recycling of the concrete block. Therefore, the
use of coconut oil with paraffin proves to be an excellent alternative to be used
as PCM and be impregnated in pumice stone, the stone present excellent level
of absorption according to the tests.
Acknowledgment:
The author thanks the Universidad Autonoma de San Luis Potosi and the
Consejo Nacional de Ciencia y Tecnologia (CONACYT)