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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Resistance assays were conducted, such as axial compression, traction by diameter compression, elastic module, and assays indicating durability such as absorption, capillary suction, speed of capillary suction and permeability to air. Concretes were analyzed in which different percentages in weight of cement was gradually replaced by the zeolite admixture. Ten mixtures were made. Section 6 indicates the dosages.

3. Characterization of the Pozzolanic Material

The zeolite was obtained from a deposit in the Cuenca de Pagancillo area, in the Department of Independencia, in the center west of the province of La Rioja, Argentina. The work was done using a clinoptilolite of the heulandite group. • Density: 2.13 g/cm 3 . Determined by means of a pycnometer. • Specific surface: 234 m 2 /kg. Calculated by fineness test method using dry sifting and by determining the specific surface by permeability to air (Blaine method) • Granulometry distribution: The sample is granulometrically heterogeneous (Figure 1) with 40.62% of its particles larger than 1000 µm (granulometry by sifting) and 59.38% of its particles smaller or equal to 1000 µm (granulometry by means of an analyzer of distribution of the size of the particles by laser diffraction Partica lA 950V2, HORIBA).

Figure 1. Granulometry of natural zeolite (NZ) of the fraction > 1000 µm (a) and < 1000 µm (b)

• Spectroscopy by X-ray fluorescence: Table 1 presents the composition of the zeolite material as per FRX using Rigaku FX2000 equipment.

Table 1. Chemical composition (%) of the pozzolanic material determined by FRX (LOI: loss of ignition) SiO 2 TiO 2 Al 2 O 3 Fe 2 O 3 MnO MgO CaO Na 2 O K 2 O P 2 O 5 LOI S Total 59.81 0.19 14.32 1.04 0.01 0.83 5.50 5.76 1.36 0.02 7.47 3.36 99.67

• Characterization by means of X-ray Diffractometry (XRD): This was carried out using a Rigaku D-Max III - C diffractometer, which works at 35 kV and 15 mA, using Cu Kα1,2 radiation (λ= 1,541840 Å) filtered with a graphite monochromator in the diffracted ray, between 3 and 60 °2θ, in 0.03 °2θ increments with one -second recounting intervals per increment. The material corresponds to a mixture of minerals; zeolite is the predominant phase. Based on the XRD presented in Figure 2, and the determination of semi-quantitative percentage of mineral phases using the RIR method proposed by Chung (1974), the sample is mainly made up of zeolite of the clinoptilolite-heulandite series (51%), gypsum (13%), albite (17%), biotite (10%) and quartz (9%).

Figure 2. Diffraction pattern of the pozzolanic material. z: zeolite, g: gypsum, p: plagioclase, b: biotite, q: quartz.