PSI - Issue 11

Bárbara Belén Raggiotti et al. / Procedia Structural Integrity 11 (2018) 36–43 Raggiotti et al./ Structural Integrity Procedia 00 (2018) 000 – 000

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6

Table 4. Dosage in kg. for one m 3 of concrete.

Material/concrete NCP40 Cement CPC40 Cement

ZN0

ZN5

ZN10 405.0

ZN15 382.5

ZN20 360.0

ZC0

ZC5

ZC10

ZC15

ZC20

450.0

427.5

-

-

-

-

-

-

-

-

-

-

450.0 185.0

427.5 185.0

405.0 185.0

382.5 185.0

360.0 185.0

Water

185.0

185.0

185.0

185.0

185.0

Addition (Zeolite) Coarse aggregate

-

22.5

45.0

67.5

90.0

-

22.5

45.0

67.5

90.0

972.5 840.3

967.6 836.0

962.6 831.8

957.7 827.5

952.7 823.2

972.5 840.3

967.6 836.0

962.6 831.8

957.7 827.5

952.7 823.2

Fine aggregate

Plastifying additive

1.6

1.6

1.6

1.6

1.6

1.6

1.6

1.6

1.6

1.6

Ratio w/c

0.41 0.41

0.43 0.41

0.46 0.41

0.48 0.41

0.51 0.41

0.41 0.41

0.43 0.41

0.46 0.41

0.48 0.41

0.51 0.41

Ratio of w/bm

7. Assays and Result Analysis

Fresh state: The consistency was determined by means of Abrams Cone (IRAM 1536 Standard, 1978). Figure 5 shows the results reached.

20

15

10

5

Slump [cm]

0

ZN0 ZN5 ZN10 ZN15 ZN20 ZC0 ZC5 ZC10 ZC15 ZC20

Figure 5. Settling measured using Abrams Cone

In fresh state, the use of the admixture, from the rheological point of view, improved cohesion; zeolite's lower density makes the volume of the cement paste plus the zeolite greater than the volume of the cement paste of the reference concrete; this situation increases the contact between solid particles giving the mixture greater cohesion. On the other hand, as can be observed in Figure 5, the mixtures lost consistency as the incorporation of zeolite increased. The phenomenon can partly be put down to the fact that this mineral is a good cation exchanger and to its porous structure which retains water. The difference in behavior between the mixtures with NPC and CPC can be put down to the composition of the cement. The only mixture with no type of admixture included, either in the concrete or the cement, is ZN0, and it was the one that settled the best, evidencing the influence of workability in the incorporation of the admixtures in the mixes. • Hardened state: Resistance to compression was defined at 7, 28, 90 and 180 days as per IRAM 1546 Standard (2013); resistance to traction by diameter compression (IRAM 1658, 1995), elastic module at 28 days (ASTM C469, 2014), absorption (ASTM C642, 2013), suction and speed of capillary suction (IRAM 1871, 2004) and permeability to air (Swiss Standard SIA 262/1-E, 2003). Figure 6 shows resistance to compression at different ages.

0 10 20 30 40 50 60 70

7 28 90 180

Strenght [MPa]

ZN0

ZN5 ZN10 ZN15 ZN20

ZC0

ZC5

ZC10 ZC15 ZC20

Figure 6. Resistance to compression at different ages