Printer Friendly

Investigation of the Effects of Marble Material Properties on the Surface Quality.

1. Introduction

Marble is an extremely popular ornamental stone for architectural and sculptural purposes. It also has a high potential of taking a polish. Grinding and polishing processes are generally used as the finishing process to obtain polished surfaces which are widely preferred in the global market for decorative purposes due to the pleasing appearance they present [1]. The parameters affecting the efficiency of grinding and polishing processes have been widely investigated in previous studies; however, it is still not understood exactly how the parameters affect the final polish [2]. The effects of material properties on surface quality were investigated by Erdogan [3], and factors such as porosity, distinct crystal boundaries, cleavages, fillings in the microfractures, and obliqueness between the crystal orientation and the cutting plane were found to be adversely affecting the surface quality. Gorgiflu and Ceylanoglu [4] investigated the effects of diamond and SiC abrasives on the surface quality and discovered that surface roughness and glossiness of the stone samples they examined were independent of the abrasive type used. For that reason, the importance of choosing the appropriate series of abrasives and adjusting operational conditions specifically for the stone properties to achieve the desired surface quality was emphasized. The microstructure detection of a glossy granite surface at each separate stage ranging from sawing to grinding was studied by Huang et al. [5]. They concluded that the highest glossiness surface of the workpiece was also the lowest roughness surface which was shaped by diamond grinding in the ductile mode. Ersoy and Kose [6] investigated the relationship between polishing ease and mechanical properties of marble. Their research showed that the strength to wear by friction affects the brightness in marbles, and there is an inverse relationship between the brightness and the abrasion index.

Yavuz et al. [7] examined the effects of belt speed on surface quality by performing polishing tests at various constant rotational speed values and pressure levels of the polishing head. According to the data obtained, optimum polishing quality conditions were met at the belt speed value of 1.3m/min. Karaca [2] studied the relationship between mechanical properties and the surface roughness of true marble samples and found that there are significant correlations between uniaxial compressive strength, tensile strength, and the surface roughness of the marble specimens. It has not been clearly demonstrated whether the value of the Bohme abrasion loss correlates with the polished marble surface roughness. Gurcan et al. [8] emphasized that different microroughness levels and gloss values were observed due to the different textures and chemical compositions of marble samples studied. Ersoy et al. [9] investigated the effect of abrasive head rotation on the surface quality and revealed that smoother and brighter surfaces are obtained by increasing the abrasive head's rotational speed.

The main objective of this study is to determine the effects of physicomechanical and mineralogical-petrographical properties and chemical contents of limestones on their final glossiness and roughness values. To that end, physicomechanical properties such as unit weight (UW), porosity (P), uniaxial compressive strength (UCS), flexural strength (FS), indirect tensile strength (ITS), BOhme abrasion resistance (BAR), and Schmidt hardness (SH) were determined first. Mineralogical-petrographical characterizations of the samples were done using thin-section analysis, and chemical content of samples was determined by the application of XRF semiquantitative method. Then, polishing tests were conducted, and surface roughness and glossiness of marble strips were measured. Finally, interpreting the obtained data, the effect of material properties on surface quality of marble specimen was determined.

2. Materials and Experimental Procedure

2.1. Determining Material Properties. To determine the physicomechanical properties of the selected marble samples, workpieces were prepared and UW, P, UCS, SH, and ITS tests were conducted according to ISRM [10] standards, whereas FS and BAR tests were conducted according to TS 699 [11]. Thin sections of marble samples were analyzed for mineralogical-petrographical characterizations.

2.2. Polishing Tests. Polishing tests were carried out by using a laboratory-scaled polishing machine designed to be similar to an industrial-scaled machine, equipped with a conveyor belt of 60 cm width and four polishing heads of 35 cm diameter (Figure 1). An abrasive series consisting of 60, 80, 120, 180, 220, 280, 320, 380, 600, and 800, 5 Extra, and a felt pad (Pulitore) were used. The workpieces were obtained from a marble processing plant and were calibrated with diamond abrasives in dimensions of 500 mm long, 300 mm wide, and 20 mm thick. Ten points were marked on the edges of the strips to ensure that the roughness and glossiness measurements were taken from the same points for all samples. Operational polishing machine variables such as belt speed and rotational speed of the polishing head were fixed at 1.48 m/min and 499.5 rpm, respectively. Pressure of the polishing head was kept at 1.25 bar for 60-800 numbered abrasives and reduced to 1 bar for 5 Extra and Pulitore cases. 60 numbered five abrasives were mounted on a grinding head, and six separate polishing tests were conducted for each marble unit by using only one polishing head. After the polishing stage, a compressor was used to blow off the dust and the water drops remaining on the surface of the strips.

2.3. Surface Quality Measurements. To determine the surface quality of the strips, roughness and glossiness measurements were taken. Taylor Hobson Surtronic 3+ portable surface roughness tester and Konica Minolta Multigloss 268 glossmeter are shown in Figure 2, respectively. The roughness values were measured in terms of the most commonly used parameter "[R.sub.a]," and the glossiness values were evaluated for a 60[degrees] angle and a 9 x 15 mm area. Arithmetic mean of ten measurements was calculated, and surface profiles of the strips were determined after all six polishing tests were carried out. The same procedure was repeated for the rest of the abrasive series, and the final surface quality of the strips was assessed after Pulitore was used for each marble unit.

3. Results and Discussion

The results of the laboratory measurements and the chemical content of the workpieces are presented in Tables 1 and 2, respectively [1]. Mineralogical and petrographical characterizations of marble samples are given in Table 3 [1].

The average roughness and glossiness values obtained from the six polishing tests versus abrasive numbers for each marble unit are given in Figure 3. It is seen from Figure 3 that roughness values follow an exponentially decreasing trend towards the end of the abrasive series, while it is exponentially increasing for glossiness values for the majority of the surface finish operations as expected [2, 4, 5, 7, 8]. It is clear that small abrasive numbers 60,80, and 120 with coarse abrasive grains have a more prominent effect on the decrease in surface roughness, and finer-grained abrasives (360, 600, and 800) cause a significant increase in surface glossiness values but the most pronounced effect is due to 5 Extra and Pulitore. It can also be seen from Figure 3 that there is an inverse relationship between final surface roughness and glossiness. Therefore, a distribution plot was drawn in order to show the relationship between roughness and glossiness values and calculate the correlation coefficient (Figure 4, r = -0.96) [1].

Analysis of the final roughness and glossiness values showed that glossiness of each marble unit was more than 87% except Emperador. Although the polishing tests were conducted under the same operational conditions, the glossiness of Emperador turned out to be 80% which is lower than the other samples. In order to clarify the reason behind this difference, parameters affecting the surface glossiness were investigated. In a previous study conducted by Erdogan [3], it was stated that geologic discontinuities such as cleavage, porosity, crystal boundary, fillings of the microfractures, and also the types of mineral constituting the rock have a negative effect on the surface glossiness [3]. In terms of physical properties, the Emperador unit was found to be more porous (Table 1) than the other marble units. The micro- and macropores in the structure of the Emperador absorb incoming beams and diminish the surface glossiness values. By taking mineralogical and petrographical characterizations into account, we can say that discontinuities such as filled fractures and the intersecting veins reflect the incoming beams in different directions. When analyzed in terms of the chemical content, the higher rate of MgO and the lower rate of CaO in the structure of the Emperador (Table 2) compared to the other marble units are significant. It was stated in previous studies that the increase in MgO ratio in the marble structure has a negative effect on surface roughness and glossiness [8, 12], which supports our findings.

To examine the effects of each physicomechanical property on surface roughness and glossiness values, correlation and regression analyses were conducted. A linear correlation (r [greater than or equal to] 0.95) was observed between porosity and the surface quality. With increasing porosity, roughness also increased while glossiness decreased (Figures 5(a) and 5(b)). There is an inverse relationship between UCS and roughness as well as ITS and roughness (Figures 5(c) and 5(e)), whereas the relationship between UCS (or ITS) and glossiness is directly proportional (Figures 5(d) and 5(f)). The correlation coefficients between the UW, BAR, FS, and SH test results and polishing test results were lower than 48%, and thus, these values were not high enough to suggest the existence of a relationship between them.

4. Conclusion

In this study, polishing tests were applied on four types of limestones under fixed operational conditions. Glossiness and roughness values were measured after each polishing stage for all specimens. Considering the polishing test results, it is clear that 60, 80, and 120 numbered abrasives with coarse grains have a more prominent effect on the decrease of the surface roughness levels while glossiness values did not show a remarkable increase up to 320 numbered abrasive, and also finer-grained abrasives have the dominant effect on the increase of the glossiness values. It was seen that there is a good correlation (r = 0.96) between final surface glossiness and roughness values, and glossiness increases with decreasing roughness.

Although all the marble samples were of limestone and the polishing tests were applied under the same operating conditions, final surface glossiness of the Emperador unit was lower than the other units. The reason for that is the fact that the micro- and macropores in the structure of Emperador absorb the beams rather than reflecting them, and discontinuities such as filled fractures and intersecting veins reflect the incoming beams in different directions. Also, a high amount of MgO in marble samples has a negative effect on the surface quality. Based on laboratory measurements, linear relationships were found between P, UCS, and ITS and the surface quality.

Conflicts of Interest

The authors declare that they have no conflicts of interest.


[1] S. Cevheroglu Cira, The Investigation of the Effects of Operational Variables of Polishing Machine and Material Properties of Marble on Surface Quality and Optimization, Ph.D. thesis, Cukurova University, Adana, Turkey, 2014.

[2] Z. Karaca, "Relationship between the mechanical properties and the surface roughness of marble," International Journal of Materials Research, vol. 103, no. 5, pp. 633-637, 2012.

[3] M. Erdogan, "Measurement of polished rock surface brightness by image analysis method," Engineering Geology, vol. 57, no. 1-2, pp. 65-72, 2000.

[4] K. Gorgulii and A. Ceylanoglu, "Evaluation of continuous grinding tests on some marble and limestone units with silicon carbide and diamond type abrasives," Journal of Materials Processing Technology, vol. 204, no. 1-3, pp. 264-268, 2008.

[5] H. Huang, Y. Li, J. Y. Shen, H. M. Zhu, and X. P. Xu, "Microstructure detection of a glossy granite surface machined by the grinding process," Journal of Materials Processing Technology, vol. 129, no. 1-3, pp. 403-407, 2002.

[6] M. Ersoy and H. Kose, "The relationship between easiness to polishing and mechanical properties of marbles," in Proceedings of the National Marble Symposium, pp. 337-349, Afyon, Turkey, June 2001, ekler/e4243f5511fd6efek.pdf.

[7] H. Yavuz, T. Ozkahraman, and S. Demirdag, "Polishing experiments on surface quality of building stone tiles," Construction and Building Materials, vol. 25, no. 4, pp. 1707-1711, 2011.

[8] S. Gurcan, R. M. Goktan, and A. Yildiz, "Effect of mineralogical and microstructural properties on surface roughness and gloss of some ornamental marbles subjected to polishing process," X-Ray Spectrometry, vol. 43, no. 2, pp. 70-78, 2014.

[9] M. Ersoy, L. Yesilkaya, M. Y. Celik, and Y. Gecer, "Investigation of the belt conveyor speed effect to the surface quality in marble polishing process," Journal of Polytechnic, vol. 17, no. 4, pp. 153-160, 2014.

[10] International Society for Rock Mechanics, "Rock characterization, testing and monitoring," in ISRM Suggested Methods, E. T. Brown, Ed., ISRM, Oxford, UK, 1981.

[11] Turk Standartlari Enstitusu, TS 699: Tabii Yapi Taslari-Muayene ve Deney Metotlari, Ankara, Turkey, 1987.

[12] Z. Karaca, "Effect of Head Pressure and Abrasive Series on Surface Roughness of Marbles," in Proceedings of the 22nd International Conference on Surface Modification Technologies, vol. 22-24, pp. 289-296, Trollhattan, Sweden, September 2008.

Sumeyra Cevheroglu Cira (iD), (1) Ahmet Dag, (2) and Askeri Karakus (iD) (1)

(1) Mining Engineering Department, Faculty of Engineering, Dicle University, Diyarbakir, Turkey

(2) Mining Engineering Department, Faculty of Engineering, Qukurova University, Adana, Turkey

Correspondence should be addressed to Sumeyra Cevheroglu Cira;

Received 12 September 2017; Accepted 12 November 2017; Published 28 January 2018

Academic Editor: Robert Cerny

Caption: Figure 1: Laboratory-scaled polishing machine.

Caption: Figure 2: Measurement of (a) surface roughness and (b) glossiness.

Caption: Figure 3: Surface roughness and glossiness values versus abrasive number for (a) Adara, (b) Emperador, (c) Crema nera, and (d) Sand wave.

Caption: Figure 4: Roughness versus glossiness.

Caption: Figure 5: Physicomechanical properties versus roughness and glossiness. (a) Porosity versus roughness. (b) Porosity versus glossiness. (c) Uniaxial compressive strenght versus roughness. (d) Uniaxial compressive strenght versus glossiness. (e) Tensile strenght versus roughness. (f) Tensile strenght versus glossiness.
Table 1: Results of physicomechanical tests.

Marble unit        UW          P (%)   UCS (MPa)   FS (MPa)

Adara              25.7        0.39      77.9       15.01
Emperador          25.8        1.85      61.69      13.44
Crema nera        26.59        0.34      83.99       12.9
Sand wave         27.08        1.46      72.05       8.96

Marble unit   ITS (MPa)   BAR ([cm.sup.3]/    SH
                           50 [cm.sup.2])

Adara           7.53           15.76         39.2
Emperador       7.23           18.79         41.2
Crema nera       8.6           15.41         43.6
Sand wave       7.35            7.95          40

Unit weight (UW), porosity (P), uniaxial compressive strength (UCS),
flexural strength (FS), indirect tensile strength (ITS), Bohme
abrasion resistance (BAR), and Schmidt hardness (SH).

Table 2: Results of XRF semiquantitative analysis.

Content (%)                   Marble unit

                      Adara    Emperador    Crema nera   Sand wave

CaO                   55.16      47.06        55.09        55.03
MgO                   0.67       14.7          1.13        0.53
[Al.sub.2][0.sub.3]   0.38        --           0.16         0.3
MnO                   0.035      0.022         0.02         --
CuO                   0.026      0.032        0.026         --
[Fe.sub.2][0.sub.3]   0.21       0.14         0.105        0.33
[Cr.sub.2][O.sub.3]   0.058      0.04         0.025        0.036
S[O.sub.3]            0.117       --          0.066        0.084
[Lu.sub.2][O.sub.3]   0.02       0.055         0.04        0.04
[V.sub.2][O.sub.5]     --        0.058          --         0.008
SrO                    --        0.17           --          --
Mo[O.sub.3]            --        0.63           --          --
[Yb.sub.2][0.sub.3]    --        0.01           --          --
[La.sub.2][O.sub.3]    --         --           0.06         --
Ti[0.sub.2]            --         --            --         0.03
[Eu.sub.2][O.sub.3]    --         --            --         0.06
[Tu.sub.2][O.sub.3]    --         --            --         0.32
Loss on ignition      43.3       37.0          43.3        43.2

Table 3: Mineralogical and petrographical characterizations
of the marble samples.

Sample Name   Petrographic description                   Thin section

Adara           Yellowish gray-colored, massive, and
               fine-grained "micritic limestone." The
                main component is micritic carbonate
                 minerals; however, large carbonate
              crystals (calcite) are also present. In
                some sections, calcite minerals are
              observed to be dense and in contact with
              each other. Binding between minerals is
                 not observed. Numerous thin veins
              intersecting each other give a segmented
                appearance to the marble and can be
              observed in macroscopic scale. Veins are
              filled with carbonate crystals (calcite)

Emperador     Pale yellowish brown, massive, and fine-
              grained "calcitic dolomite." It consists
                 of crystalline carbonate minerals
                  (dolomite and a small amount of
                 calcite). Marble gains rotational
              movement because of its position between
              nonparallel strike-slip faults. It shows
               a tectonite structure with both small
              and large particles, and these particles
                are bound to each other with calcite
                cement. Heterogeneously distributed,

                 irregular, carbonate-filled veined
                structure is observed throughout the

Crema nera    A very pale orange-colored, massive, and
              fine-crystallized "micritic limestone."
                 It consists of micritic carbonate
                minerals. Slightly larger grains of
              carbonate (calcite) were observed to be
                 bound by the cryptocrystalline mud

Sand wave        Yellowish gray, massive, and fine-
                grained "biomicritic limestone." The
                main component is micritic carbonate
               minerals. The interiors of these small
                  grains are filled with micritic
               carbonate minerals. Also, fine-grained
              carbonate oolite and fossil shells were
                 observed in some places. There is
              ferrous water in its structural stilolit
               gaps, and this hematite-stained water
                   causes redness in these parts
COPYRIGHT 2018 Hindawi Limited
No portion of this article can be reproduced without the express written permission from the copyright holder.
Copyright 2018 Gale, Cengage Learning. All rights reserved.

Article Details
Printer friendly Cite/link Email Feedback
Title Annotation:Research Article
Author:Dag, Sumeyra Cevheroglu Cira Ahmet; Karakus, Askeri
Publication:Advances in Materials Science and Engineering
Date:Jan 1, 2018
Previous Article:Experimental and Numerical Investigation of Concrete-Filled Double-Skin Steel Tubular Column for Steel Beam Joints.
Next Article:The Effects of Combined Micron-Scale Surface and Different Nanoscale Features on Cell Response.

Terms of use | Privacy policy | Copyright © 2022 Farlex, Inc. | Feedback | For webmasters |