Printer Friendly

Dry ripened mortar with quarry waste and rubber powder from unserviceable tires/Argamassa maturada seca com residuos de pedreira e po de borracha de pneus inserviveis.

Introduction

The growing demand for materials used in civil construction in Brazil is increasing every year. With this, the consumption of raw materials increases, including natural sand which is mostly extracted from riverbeds, and causing damages to the environment. Government agencies such as IBAMA (Brazilian Institute of Environment and Renewable Natural Resources) have restricted this practice as a form of environmental conservation.

An alternative material to replace the natural sand is the quarry waste, called stone-quarry fines or artificial sand, resulting from the process of crushed stone production in quarries. This material has been examined for use in mortar and concrete replacing natural sand.

One of the factors that distinguish artificial from natural sand is the higher content pulverulent materials. For Bonavetti and Irassar (1994) accelerating cement hydration due to the effect of stone dust contributes to gain strength at early ages, and with this there are drying shrinkage and a positive effect of filler, increased water retention and improved plasticity. Jadhav and Kulkarni (2012) also reported an increase in mechanical properties, in addition to the reduction in workability, requiring increased water consumption, although the authors have obtained a more cohesive concrete.

Ilangovana et al. (2008) also verified a higher drying shrinkage in concrete with artificial sand, but the permeability was lower given the increased content of fines. And Donza and Cabrera (2002) mentioned that the increase in mechanical properties, even with a higher water / cement ratio, can be associated with the improvement of the paste-fine aggregate transition zone, which can be attributed to the rough texture of the artificial sand.

By using up to 15% artificial sand in high-performance concrete, Beixing et al. (2009) verified that it had not affected the permeability of chloride ions, freezing and thawing. However, in low strength concrete the freezing was affected. Raman et al. (2011) evaluated the high-performance concrete with artificial sand and rice husk ash, and obtained a negative impact for the workability in fresh concrete, but it was compensated with a good dosing design, and by the use of a superplasticizer and a mixture of rice husk ash.

An alternative material with characteristics and conditions to be used to reduce the drying shrinkage and crackings in mortar lining with stone-quarry fines is the rubber powder from unserviceable tires, which can be used either as replacement or in addition to mortar and concrete. Several authors have developed studies with this material as rubber aggregate of various sizes (SEGRE et al., 2004; HERNANDES-OLIVARES et al., 2004; GANJIAN et al., 2009; MOHAMMED, 2010).

In the study conducted with rubber aggregate in concrete, Ho et al. (2012) achieved a reduction in the brittle index of concrete with increasing rubber content and reached nearly zero with 40%, and that the kinetics of the fracture process of concrete with rubber is slower in relation to concrete without rubber. For Turatsinze and Garros (2008) despite the reduction in tensile and compressive strength of concrete, there was an improvement in the ability to absorb deformation and a reduction in potential detrimental effect of cracking, while the study of Turatsinze et al. (2007) showed that free shrinkage is improved as well as the reduction of cracking of resistant mortar.

Canova et al. (2012) analyzed mortar of quicklime and natural sand (which was oven-dried and added of rubber powder from unserviceable tires), and observed an improvement in relation to conventional mortar, with reduced water exudation, free shrinkage and cracking. The addition of 8% rubber powder from unserviceable tires was the most suitable ratio. In other study of Canova et al. (2009), the water absorption by capillarity was significantly reduced by adding rubber powder for the oven-dried mortar, and still reduced drying shrinkage with restricted surface and the void content, besides presenting a mortar with great tenacity

In this study we examined the plastering mortar with artificial sand replacing natural sand, and addition of 8% rubber powder form unserviceable tires, in which it was used the process described in Canova et al. (2012) that resulted in dry ripened mortar and established that this addition was the most suitable.

In this way, we sought to minimize environmental impacts problems and mainly to reduce the cracking of coatings, which were more pronounced in mortars with artificial sand.

Material and methods

In order to compose the volumetric proportion of mortars, it was used powder quicklime type CV--C (common quicklime), artificial sand (stone-quarry fines), natural river sand, class 32 compound Portland cement (CP II Z--32) and addition of rubber powder from ground unserviceable tires with diameter below 0.5 mm. The characterization of materials and of the addition employed is presented in Tables 1--6.

Mortar preparation

Simple mortars were prepared with quicklime and fine aggregate (artificial and natural sand) both in volumetric proportions of 1:6, were previously prepared in a 320-L inclined axle cement mixer and ripened for seven days in metal containers for quicklime hydration in laboratory ambient. After maturation, the mortar mass was determined and it was dried into a constant mass in an oven at (105 [+ or -] 10)[degrees]C. The dry mortar mass was determined and then it was grinded and sieved with a mesh of (2.4 mm), packed in grained state in plastic bags and stored for 60 days in closed dry wooden containers. Ripened and dried mortars were tested with cement composing the volumetric proportions of 1:1.5:9--equivalent in weight 1:0,993:9.623 and added 8% rubber powder from unserviceable tires and named as:

[As.sup.0.sub.RP]--Oven-dried mortar with artificial sand (stone-quarry waste), packed, and stored for 60 days. The index '0' indicates reference mortar, that is, without rubber powder and likewise [As.sup.0.sub.AN]--with natural sand.

[As.sup.8.sub.RP]--Oven-dried mortar with artificial sand. The index '8' indicates the addition of 8% rubber powder and likewise [As.sup.8.sub.AN]--with natural sand.

Measured properties

The volumetric proportion of ripened and dried mortars was evaluated through properties at plastic and hardened states, by means of standardized laboratory tests, as presented in Table 7. For testing mortars in the hardened state were molded the series with six cylindrical specimens with 5 cm diameter and 10 cm height, for all tests developed and tested with 28 days of age.

Crackings--It was measured the length of visible crackings on mortar panels with 1.5 cm thickness, in the dimension of 1.0 m2, with 1:3 usual roughcast (cement and sand, by volume), on ceramic block masonry at once, in environment outside of the laboratory. Measurements were taken with 24 hours and after 90 days.

Results and discussions

Results in the plastic state

Table 8 shows the ratio parameters of the mortars.

Specific gravity and void content

In Figure 1 is observed the increase in specific gravity in the plastic state for the ripened dried mortar with stone-quarry wastes in relation to natural sand. This is due to the higher specific gravity of the quarry waste. However, with the addition of rubber powder that has low specific gravity, there was a decrease for both mortars.

The dried mortar with quarry waste presented a reduction in the incorporated air content (Figure 2). This may have occurred owing the greater amount of pulverulent material of the artificial sand compared with natural sand. As for the rubber powder, there was an increase in air content because the rubber grain has a lower compactness.

Water bleeding

A sharp reduction was found in water bleeding from dried mortar with quarry waste in relation to natural sand (Figure 3). In the same way, a decrease for both mortars with 8% rubber powder was observed, with a greater reduction for mortar with quarry waste. The rubber powder and the fine material from artificial sand may have favored the closure of the pore structure of the mortar, contributing to reduce the water bleeding.

Water retention

The ripened dried mortar with quarry waste presented a greater retention of water compared with the mortar with natural sand (Figure 4), due to the higher amount of fines in the aggregate. The addition of rubber powder contributes even more for the closure of the pore structure of the mortar, generating thus a greater retention of water in the mortar with artificial sand in relation to the mortar with natural sand.

Hardened state results

Axial compressive strength

There was a slight increase in axial compressive strength at 28 days for the dried mortar with artificial sand in comparison with natural sand (Figure 5). This probably occurred given the reduction in incorporated air content, which leads to a higher compactness, directly proportional to the higher compressive strength; this corroborates the observations made by Bonavetti and Irassar (1994), with reduction for both mortars with addition of rubber powder, once it presented a low mechanical strength.

Static deformation modulus

The static deformation modulus of the dried mortar with artificial sand was slightly higher than of the mortar with natural sand (Figure 6), as also observed for the compressive strength. The addition of rubber powder led to a reduction in static deformation modulus, in the same way with further reduction for the mortar with natural sand, presenting an improvement in the ability to absorb deformation; confirming the observations of Turatsinze and Garros (2008).

Water absorption by capillarity

The water absorption by capillarity of the dried mortar with artificial sand was higher than of the mortar with natural sand (Figure 7). The greater content of fines in the artificial sand might have led to a greater microcraking of this mortar, or even to a reduction in the radius of capillary, increasing thus the surface tension. Considering the addition of 8% rubber powder, although with lower rates, the mortar with artificial sand also had a much higher capillarity rate compared with the mortar with natural sand, and a much shorter time to reach the top of the specimen, as registered by Canova et al. (2009).

Visible cracking

The mortar with artificial sand cracked more than the mortar with natural sand (Figure 8), probably due to the higher amount of fines present in the quarry waste.

Besides, with 24 hours the incidence of crackings was higher than at 90 days. The addition of rubber powder has positively contributed to both mortars. This may have occurred due to increased retention of water and/or reduction in deformation modulus. Figure 9 illustrates the total sum of crackings of times of 24 hours and 90 days. The mortar with quarry waste had a higher amount of crackings than the mortar with natural sand.

Conclusion

Replacement of the natural sand in the quarry waste in dried mortar contributed to reduction in water bleeding, increase in compressive strength and water retention. But reduced the void content and increased the static deformation modulus and visible cracking.

The addition of rubber powder in dried mortar with quarry waste contributed to the increase in void content and water retention, with reducing to the water bleeding, water absorption by capillarity and significantly reduced the appearance of visible cracking. Although there was been decrease in mechanical properties. We conclude that use of 8% rubber powder is feasible to reduce cracking.

Doi: 10.4025/actascitechnol.v37i1.19907

References

AB NT-Associacao Brasileira de Normas Tecnicas. NBR 7251: agregados em estado solto: determinacao da massa unitaria: metodo de ensaio. Rio de Janeiro: ABNT, 1982.

ABNT-Associacao Brasileira de Normas Tecnicas. NBR 8522: concreto: determinacao do modulo de deformacao estatica e diagrama--tensao deformacao: metodo de ensaio. Rio de Janeiro: ABNT, 1984.

ABNT-Associacao Brasileira de Normas Tecnicas. NBR 7217: agregados em estado solto: determinacao da composicao granulometrica: metodo de ensaio. Rio de Janeiro: ABNT, 1987.

ABNT-Associacao Brasileira de Normas Tecnicas. NBR MB 3432: cimento portland: determinacao da finura por meio da peneira 75 pm (no 200). Rio de Janeiro: ABNT, 1991.

ABNT-Associacao Brasileira de Normas Tecnicas. NBR 13276: argamassa e revestimentos de paredes e teto: determinacao do teor de agua para obtencao do indice de consistenica-padrao: metodo de ensaio. Rio de Janeiro: ABNT, 1995.

ABNT-Associacao Brasileira de Normas Tecnicas. NBR 13277 argamassa para assentamento de paredes e revestimentos de paredes e teto: determinacao da retencao de agua--argamassa de revestimento: metodo de ensaio. Rio de Janeiro: ABNT, 1995.

ABNT-Associacao Brasileira de Normas Tecnicas. NBR 13278: argamassa e revestimentos de paredes e teto: determinacao da densidade de massa e do teor de ar incorporado: metodo de ensaio. Rio de Janeiro: ABNT, 1995.

ABNT-Associacao Brasileira de Normas Tecnicas. NBR 13279: argamassa para assentamento de paredes e revestimentos de paredes e teto: determinacao da resistencia a compressao: metodo de ensaio. Rio de Janeiro: ABNT, 1995.

ABNT-Associacao Brasileira de Normas Tecnicas. NBR 9779: argamassa para assentamento de paredes e revestimentos de paredes e teto: determinacao da absorcao de agua por capilaridade: metodo de ensaio. Rio de Janeiro: ABNT, 1995.

ABNT-Associacao Brasileira de Normas Tecnicas. NBR 7215: cimento portland: determinacao da resistencia a compressao. Rio de Janeiro, 1995.

ABNT-Associacao Brasileira de Normas Tecnicas. NBR NM 23: cimento portland: determinacao da massa especifica. Rio de Janeiro: ABNT, 1998.

ABNT-Associacao Brasileira de Normas Tecnicas. NBR 9289: cal hidratada para argamassas: determinacao da finura: metodo de ensaio. Rio de Janeiro: ABNT, 2000.

BEIXING, L.; JILIANG W.; MINGKAI Z. Effect of limestone fines in manufactured sand on durability of low-and high-strength concretes. Construction and Building Materials, v. 23, n.1, p. 2846-2850, 2009

BONAVETTI, V. L.; IRASSAR, E. F. The effect of stone dust content in sand. Cement and Concrete Research, v. 24, n. 3, p. 580-590, 1994.

CANOVA, J. A.; BERGAMASCO, R.; DE ANGELIS NETO, G. Comparative analysis of the properties of composite mortar with addition of rubber powder from worm tires. Ambiente Construido, v. 12, n. 1, p. 7-23, 2012.

CANOVA, J. A.; DE ANGELIS NETO, G.; BERGAMESCO, R. Mortar with unserviceable tire residues. Journal of Urban and Environmental, v. 3, n. 2, p. 63-72, 2009.

DONZA, H.; CABRERA, O. High-strength concrete with different fine aggregate. Cement and Concrete Research, v. 32, n. 11, p. 1755-1761, 2002.

GANJIAN, E.; KHORAMI, M.; MAGHSOUDI, A. A. Scrip-tyre-rubber replacement for aggregate and filler in concrete. Construction and Building Materials, v. 23, n. 5, p. 1828-1836, 2009.

HERNANDES-OLIVARES, F.; BARLUENGA, G. Fire performance of recycled rubber-filled high-strength concrete. Cement and Concrete Research, v. 34, n. 1, p. 109-117, 2004.

HO, A. C.; TURATSINZE, A.; HAMEED, R.; VU, D. C. Effects of rubber aggregates from grinded used tyres on the concrete resistance to cracking. Journal of Cleaner Production, v. 23, n 1, p. 209-215, 2012.

ILAN GOVANA, R.; MAHENDRANA, N.; NAGAMANIB, K. Strength and durability properties of concrete containing quarry rock dust as fine aggregate. ARPN Journal of Engineering and Applied Sciences, v. 3, n. 5, p. 20 -26, 2008.

RILEM-International Union of Testing and Research Laboratories for Materials and Structures. MR--6: tendency of water to separate from mortars (bleeding). France: Rilem, 1982.

JADHAV, P. A.; KULKARNI, D. K. An experimental investigation on the properties of concrete containing manufactured sand. International Journal of Advanced Engineering Technology, v. 3, n. 2, p. 101-104, 2012.

MOHAMMED, B. S. Structural behavior and m-k value of composite slab utilizing concrete containing crumb rubber. Construction and Building Materials, v. 24, n. 7, p. 1214-1221, 2010.

RAMAN, S. N.; NGO, T.; MENDIS, P.; MAHMUD, H. B. High-strength rice husk ash concrete incorporating quarry dust as a partial substitute for sand. Construction and Building Materials, v. 25, n. 7, p. 3123-3130, 2011.

SEGRE, N. C.; JOEKES, I.; GALVES, A. D.; RODRIGUES, J. A. Rubber-Mortar Composites: effect of composition on properties. Journal of Materials Science, v. 39, n. 10, p. 3319-3327, 2004.

TURATSINZE, A.; GARROS, M. On the modulus of elasticity and strain capacity of Self--Compacting Concrete incorporating rubber aggregates. Resources, Conservation and Recycling, v. 52, n. 10, p. 1209-1215, 2008.

TURATSINZE, A.; BONNET, S. GRANJU J. L. Potential of rubber aggregates to modify properties of cement based-mortars: Improvement in cracking shrinkage resistance. Construction and Building Materials. v. 21, n. 1, p. 176-181, 2007.

Received on February 25, 2013.

Accepted on February 2, 2014.

Jose Aparecido Canova (1), Generoso De Angelis Neto (1) and Rosangela Bergamasco (2)

(1) Departamento de Engenharia Civil, Universidade Estadual de Maringa, Av. Colombo, 5790, 87020-900, Maringa, Parana, Brazil. (2) Departamento de Engenharia Quimica, Universidade Estadual de Maringa, Maringa, Parana, Brazil. * Author for correspondence. E-mail: jacanova@uem.br

Table 1. Physical and mechanical characteristics of the Portland
cement (CP II Z-32).

Tests                                       Results         Methods
                                 Start    2 hours and
Setting time                               50 minutes       NBR 7215
                                  End     7 hours and     (ABNT, 1995)
                                           18 minutes

Normal consistency                       Water / cement     NBR 7215
                                          ratio = 0.30    (ABNT, 1995)

Fineness--(% retained on                      1.62          MB 3432
sieve # 200)                                              (ABNT, 1991)

Unit weight (g [cm.sup.-3])                   1.45          NBR 7251
                                                          (ABNT, 1982)

True density (g [cm.sup.-3])                  3.09           NM 23
                                                          (ABNT, 1998)

Compressive strength (MPa)                    34.7          NBR 7215
at 28 days                                                (ABNT, 1995)

Table 2. Physical characteristics of quicklime powder dolomitic.

Tests                    Results   Limits CV-C          Methods

Unit weight               0.96         --        NBR 7251 (ABNT, 1982)
  (g [cm.sup.-3])
True density              3.10         --         NM 23 (ABNT, 1998)
  (g [cm.sup.-3])
Fineness--(% retained)
sieve # 30                 0.7    [less than or        NBR 9289
                                  equal to] 5.0       (ABNT, 2000)
sieve # 200               0.22    [less than or
                                  equal to] 30

Table 3. Physical characteristics of the fine aggregate--fine washed
river sand.

Tests                                        Results        Methods

Unit weight                                   1.55          NBR 7251
(g [cm.sup.-3])                                              (ABNT,
                                                             1982)

True density gravity                          2.63         Pycnometer
(g [cm.sup.-3])
                         Sieve (mm)       Accumulated %
                                            retained

Particle size                2.4                0
distribution                 1.2                1           NBR 7217
                             0.6                7
                                                             (ABNT,

                             0.3               67
                                                             1987)
                            0.15               99
                       max [empty set]         1.2
                            (mm)              1.74
                          Fineness
                           modulus

Table 4. Physical characteristics of the rubber powder.

Determination                           Results        Methods

Unit mass                                 0.44         NBR 7251
(g [cm.sup.-3])                                      (ABNT, 1982)

True density                              0.79        Pycnometer
(g [cm.sup.-3])
                      Sieve (mm)      Accumulated
                                       % retained

Particle size            0.6               0           NBR 7217
distribution             0.3               34        (ABNT, 1987)
                         0.15              99
                     [empty set]          0.42
                       max (mm)           1.33
                   Fineness modulus

Table 5. Chemical characteristics of the rubber powder--weight
in mg [kg.sup.-1]--analysis--atomic absorption spectrometry.

Fe        Cu      Mn      Zn       Pb      Cd    Cr (total)    Ni

710.00   52.60   Nd *   646.00   108.00   Nd *     32.00      4.00

Note: * Nd = not detected

Table 6. Characteristics of the fine aggregate (artificial
sand--stone-quarry fines).

Determination                            Results         Methods

Unit mass                                1.7876          NBR 7251
(g [cm.sup.-3])                                        (ABNT, 1982)

True density                              2.93          Pycnometer
(g [cm.sup.-3])
                     Sieve (mm)       Accumulated %
                                        retained
                         4.8                0
                         2.4                1
                         1.2               34
Particle size            0.6               50            NBR 7217
distribution             0.3               69          (ABNT, 1987)
                        0.15               85
                        0.075              96
                   max [empty set]         2.4
                        (mm)
                      Fineness
                       modulus            2.39

Table 7. Measured properties at plastic and hardened states.

State         Properties        Methods            Observations

Plastic      Consistency       NBR 13276
                index         (ABNT, 1995)

           Specific gravity    NBR 13278
                 and          (ABNT, 1995)
             incorporated
             void content

                Water          NBR 13277      The filter paper discs
              retention       (ABNT, 1995)   used had 80 g [m.sup.-2]
                                                  weight and air
                                               permeability of 26 l
                                               [s.sup.-1] [m.sup.2].

                Water             MR-6          With measurement in
               bleeding       RILEM (1982)    weight, in five samples
                                              in times of 15 min., 30
                                               min., 60 min. and 120
                                                       min.

Hardened        Axial          NBR 13279
             compressive      (ABNT, 1995)
               strength

                Static          NBR 8522      In the initial tangent
             deformation      (ABNT, 1984)   module, the loading speed
               modulus                        was 0,05 MPa [s.sup.-1]

           Water absorption     NBR 9779
            by capillarity    (ABNT, 1995)

Table 8. Ratio parameters of the mortars.

                        Water /      Water /   Water /   Aggregate /
Mortar               dry materials   cement    binders     binders
                         ratio        ratio     ratio       ratio
                        (mass)       (mass)    (mass)      (mass)

[As.sup.0.sub.RP]        0.216        2.59      1.356       5.27
[As.sup.0.sub.AN]        0.231        2.64      1.328       4.79
[As.sup.8.sub.RP]        0.207        2.52      1.322       5.39
[As.sup.8.sub.AN]        0.224        2.60      1.289       4.90
COPYRIGHT 2015 Universidade Estadual de Maringa
No portion of this article can be reproduced without the express written permission from the copyright holder.
Copyright 2015 Gale, Cengage Learning. All rights reserved.

Article Details
Printer friendly Cite/link Email Feedback
Title Annotation:texto en ingles
Author:Canova, Jose Aparecido; De Angelis Neto, Generoso; Bergamasco, Rosangela
Publication:Acta Scientiarum. Technology (UEM)
Date:Jan 1, 2015
Words:3306
Previous Article:Simulation of the dynamic behavior of the coffee fruit-stem system using finite element method/Simulacao do comportamento dinamico do sistema...
Next Article:Development and application of edible skin coatings to improve the quality of kinnow during storage/Desenvolvimento e aplicacao de revestimentos...
Topics:

Terms of use | Privacy policy | Copyright © 2019 Farlex, Inc. | Feedback | For webmasters