Page 361 - New Trends in Eco efficient and Recycled Concrete

316 New Trends in Eco-efficient and Recycled Concrete

Table 11.5 Highest K-values for each RAC case
K-value slabs Mix Reference

1.268 MRA (100%) Bravo et al. (2015b)
1.278 MRA (100%)
1.255 RAC (100%) Pedro et al. (2014)
1.315 RAC (100%) Cartuxo (2015, 2016)
1.285 RAC (100%)
¸
1.322 RAC (75%) Cakır (2014)
1.373 RAC (100%)
1.256 MRA (100%) Bravo et al. (2015a c)
1.358 RAC (100%) Kou et al. (2007)

RAC, recycled aggregate concrete; MRA, Mixed recycled aggegates.

1.350
1.300
1.250
K-value 1.200
1.150
1.100
1.050
1.000
1 2 3 4 5 6 7 8 9 1011121314151617181920212223242526272829
RAC mixes

Figure 11.9 Spread of the K-value for simply supported beams.

axial force which is not considered in slabs and beams. Nevertheless, the bulk vol-
ume of concrete in a regular reinforced concrete structure is in these slabs and
beams, proving the relevance of the methodology presented.

11.8 Application in LCA studies

11.8.1 State-of the art on the comparison between RCA and
NCA
There are still few LCA studies on LCA of RAC, and the available ones provide a
comparison with the LCA of conventional concrete mixes with similar compressive
strength or w/b ratio.
Hendriks and Janssen (2003) compared the eco-costs/value ratio (EVR) of con-
ventional concrete with that of RAC. The EVR model is a business-oriented defini-
tion that connects the thinking of the modern manager to the need for a more
sustainable society. The results showed that the use of RA instead of NA is very
beneficial.