As regards the mechanical properties of lightweight aggregate
concrete, according to Akça
€
ozo
glu, when the replacement ratio of
normal weight aggregate by WPLA aggregate was increased to 60%,
the compressive strength of the concrete using a 500 kg/m
cement
content was only 9.5 MPa after 28 d curing and 11.1 MPa after 90 d
curing, which indicated that the ratio of compressive strength in
MPa divided by the saturated-surface dried (SSD) density (f
/D) of
this type of lightweight aggregate concrete was only around 6.0 to
7.0 (Akça
€
ozo
glu et al., 2013). Ben Fraj et al. (2010) prepared light-
weight aggregate concrete with a polyurethane foam waste (density
21 kg/m
3
, water absorption 13.9% by volume), the results
showed that at a w/c ratio of 0.55, the normal aggregate concrete
attained a compressive strength of 38 MPa after 28 d curing while
lightweight aggregate concrete only gained 16.5 MPa (when all the
normal coarse aggregate was replaced by the polyurethane foam
waste), and the f
/D ratio was only 10.7. Strength loss due to
lightweight aggregate incorporation limited the application of
lightweight aggregate concrete in building construction.
c
But high strength lightweight aggregate concrete for structural
3
c