2.1.3. Admixtures
The results of previous research [11–13] indicated that mineral
additives could lead to the improvement of concrete properties
such as mechanical strength and concrete durability, since the
mineral composite reduced the thickness of the interfacial transition
zone (ITZ) between the aggregate and the cement matrix.
For example, the results given by [14,15] showed the ITZ thickness
of concrete was less than 10 lm with silica fume compared to
50 lmwithout silica fume. Therefore, silica fume, namely Microsilica
920-u, was tried to seek adequate strength of porous concrete
at the second stage of testing.
Besides, a new generation superplasticiser was incorporated as
the chemical intensifier in this study. It is based on a unique carboxylic
ether polymer with long lateral chains, which greatly improves
the cement dispersion. It is called hyperplasticiser.