Civil Engineering Reference
In-Depth Information
Fig. 6.11 Ratio between
concrete 28-day compressive
strengths versus ratio
between densities of
aggregates in mix (top), water
absorptions of aggregates in
mix (middle) and 7-day
compressive strengths
(bottom) of concrete
1.05
Evangelista
Figueiredo
Gomes
Rosa
Gomes (ceramics)
Gomes (mixed)
1
Ferreira
y = -2.619x + 1
R
2
= 0.7615
0.95
0.9
0.85
0.8
0.75
0.00
0.02
0.04
0.06
0.08
0.10
1-D
RAC
/D
RC
1.05
Evangelista
Figueiredo
Gomes
Rosa
Gomes (ceramics)
Gomes (mixed)
Ferreira
1
0.95
0.9
y = -0.0587x + 1
R
2
= 0.4605
0.85
0.8
0.75
0.00
1.00
2.00
3.00
4.00
5.00
wa
RAC
/wa
RC
-1
1.05
y = -0.8908x + 1
R
2
= 0.5409
1
0.95
0.9
0.85
0.8
Evangelista
Figueiredo
Figueiredo (ceramics)
Gomes (ceramics)
Ferreira
0.75
0.7
0.65
0.6
0.55
0
0.1
0.2
0.3
0.4
1-f
c7BAR
/f
c7BR
Again, there is a clear trend towards a decrease of a mechanical property of the
hardened concrete (in this case the modulus of elasticity) as the replacement rate
increases. The reason is the same as for the compressive strength, though related to
the lower stiffness of the recycled aggregates. The slope of the correlation lines is
higher for the modulus of elasticity than for the compressive strength in every
parameter, confirming a trend of greater loss of stiffness for the concrete con-
