Civil Engineering Reference
In-Depth Information
4000
W/C = 0.55
W/C = 0.44
W/C = 0.38
3500
3000
2500
2000
1500
1000
500
0
NC
GS 20
GS 40
GS 60
GS 80
Glass content (%)
11.12
Chloride ion penetration of recycled glass concrete with
different glass as replacement for sand (ASTM C1202 condition, age
28 days). Adapted from Wang (2009a).
replacement was less than that of the control groups. There is an obvious
trend that RCP values decrease with the increase in glass aggregate content.
The chloride ion penetrability decreased with the increase in recycled glass
content which means the resistance to chloride ion penetration increased
with an increase in recycled glass content. The RCP test basically measures
the conductivity (or resistivity) of concrete, which depends on both the pore
structure as well as the pore solution composition. It is clear that the test
measures movement of charge related to all ionic species and not just chloride
ions. The incorporation of glass aggregate may increase the content of alkalis
in the pore solution, thus increasing the conductivity of the pore solution.
even with such an increase, the RCP values of recycled glass concretes are
lower than that of plain concrete. It can be considered that the presence of
glass particles in concrete can reduce the permeability of the concrete mix as
discussed in Section 11.3.5, for the amount of the absorbed water in concrete
was reduced as the content of recycled glass was increased in concrete.
Concrete with glass powder exhibits good chloride penetration resistance as
well. Figure 11.13 gives the RCP value, non-steady-state migration (nSSM)
coefficient and steady state conductivity (SSC) of concrete with different
glass powder and fly ash content. As tested by different methods, recycled
glass concrete exhibits higher chloride penetration resistance than normal
concrete, especially at later ages.
