Microwave-assisted concrete recycling - Microwave-Assisted Concrete Technology: Production, Demolition and Recycling - page 164

(250.0)
140.0
126.2
112.5
98.7
85.0
71.2
57.5
43.7
30.0
(0.0)
Figure 4.14 Temperature of RCAs and separated mortar pieces after the microwave
separation process.
150°C, which is unlikely to affect the properties of the natural stone aggre-
gates after the microwave separation process. This may be considered one
of the major advantages of microwave-assisted mortar separation over the
thermal separation method. Another advantage of the microwave-assisted
mortar separation method is its short processing time, which results in con-
siderably lower energy consumption and associated emissions compared
to thermal, mechanical, and thermal-mechanical separation methods. In
addition, unlike the chemical separation method, the microwave-assisted
mortar separation method poses no additional concrete durability risk.
These advantages render the microwave-assisted mortar separation method
an appealing technique in producing high-quality RCAs.
4.7.2.2 Properties of RACs made with
microwave- treated RCAs
Section 4.2 noted that the basic properties of RCA are directly related to
its mortar content. Therefore, the reduction of mortar content is expected
to proportionally improve the quality of RCAs produced. Consequently,
any reduction in the mortar content of RCA is also expected to lead to an
improvement in RAC performance. The results of an experimental study
we conducted that was aimed at investigating the effects of incorporating
various replacement percentages of microwave-treated RCA for coarse NA
are shown in Figure 4.15 [31]. As shown, the results of this study indicate