Page 89 - New Trends in Eco efficient and Recycled Concrete

Recycled plastic 63

segregation problem in PA concrete mixes (Haghi et al., 2006; Tang et al., 2008;
Xu et al., 2012).
Fig. 3.1 shows representative workability test results on the PA concrete
obtained from the existing studies. It can be seen in the figure that the slump of
PA concrete is influenced by PA replacement level (RPA%) and shape of the
recycled plastic. As can be seen in Fig. 3.1, RPA% significantly affects the slump
of PA concrete. The slump of concrete containing uniform shape PAs increases,
whereas the slump of concrete with non-uniform shape PAs decreases with an
increase in RPA%. However, as can be seen in Fig. 3.1, some of the previous
studies showed that RPA% had no significant influence on the workability of
concrete.
Fig. 3.2 shows representative workability test results on the PF concrete
obtained from the existing studies. As can be seen in the figure, the slump of
PF concrete is influenced by PF content (RPF%). It can be seen in Fig. 3.2 that,
in most of the existing studies, the slump of fresh concrete reduced notably
with an increase in the PF content. However, Nili and Afroughsabet (2010)
reported that RPF% did not have a significant influence on the slump of concrete
containing PP.

0%
1 25% 50%
75%
0%
2 25% 50%
75%
0%
3 25% 50%
75%
0%
4 20%
40%
60%
Reference 5 80% 10%
0%
5%
15%
20%
0%
6 10%
15%
20%
0%
7 5%
10%
15%
0%
8 10%
20%
30%
0%
9 10%
20%
30%
0 100 200 300
Slump (mm)
Figure 3.1 Variation of slump of PA concrete with RPA%: 1, 2, 3 (Choi et al., 2005), 4
(Tang et al., 2008): uniform shape aggregate; 5 (Batayneh et al., 2007), 6 (Ismail and Al-
Hashmi, 2008), 7 (Rai et al., 2012), 8, 9 (Ozbakkaloglu et al., 2017): non-uniform shape
aggregate. % values represent RPA%. PA, Plastic aggregate.