2.2.3. Mechanical properties
The compressive strength (Cs) and flexural strength (Fs) of the
encapsulated materials were measured according to standard
UNE 196-1:2005 (AENOR, 2005) using an Ibertest Autotest 200-
10-W universal press (results are the means of six measurements).
UNE-EN-480-5:2006 (AENOR, 2006) was used to determine the
coefficients of water absorption by capillarity and water absorption
(Ws) of each. The water absorption by capillarity was determined
gravimetrically. Prismatic microencapsulated samples (monoliths
measuring 40 40 160 mm) were dried at 50 C in an oven until
a constant mass was reached. They were then placed on a grating in
a dish containing water at room temperature and humidity of 60%;
the water level was only high enough to wet the lower surface of
the test samples. The lower parts of the sides of the specimens
adjoining the inflow face were sealed with an adhesive to prevent
any water being absorbed by their surface pores. Mass data for each
specimen were recorded over time until a constant value was
reached. All experiments were performed in triplicate. Ws (g cm2
)
was calculated according to the equation below:
Ws ¼ DM=S ¼ Mj M0
16 ð2Þ
where Mj is the mass of the test sample after 28 days of immersion,
M0 the initial mass, and S is the surface area in contact with the
water (16 cm2 for all test samples).
2.2