Methodologies for Estimating Properties of Concrete Containing Recycled Aggregates: Analyses of Experimental Research - Recycled Aggregate in Concrete - page 355

Fig. 6.8 Ratio between the
7-day carbonation depths of
concrete versus the ratio
between the densities (top),
the water absorptions (centre)
of the mixture of aggregates
and the 7-day compressive
strengths of concrete (bottom)

1.8

Katz

1.7

1.6

y = 6.506x + 1
R 2 = 0.7616

1.5

1.4

1.3

1.2

1.1

1

0 0.02 0.04 0.06 0.08 0.1

1-D RAC / D RC

1.8

Katz

1.7

1.6

y = 0.178x + 1
R 2 = 0.7616

1.5

1.4

1.3

1.2

1.1

1

0 0.5 1 1.5 2 2.5 3

wa RAC /wa RC -1

1.8

Katz

1.7

1.6

y = 1.5452x + 1
R 2 = 0.8291

1.5

1.4

1.3

1.2

1.1

1

0 0.1 0.2 0.3 0.4 0.5

1-f c7RAC /f c7RC

Although this conclusion is based on the results of a single campaign, the slopes
of the correlation lines in Fig. 6.8 are the highest for all the properties analysed so
far, which gives a good indication that RCA are especially susceptible to this
mechanism of degradation that initiates the steel reinforcement corrosion process,
as reported in the existing literature (Buyle-Bodin and Zaharieva 2002 ; de Brito
2005 ; Levy 2001 ; Merlet and Pimienta 1993 ).