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Scientific Research and Essays Vol. 5(8), pp. 750-757, 18 April, 2010

Available online at http://www.academicjournals.org/SRE

Full Length Research Paper

Geomechanical properties of construction stones

quarried in South-western Turkey

Saffet Yagiz

Department of Geological Engineering, Faculty of Engineering, Pamukkale University, Denizli 20020, Turkey.

Turkish Standard Institute for TSE/MTC109, Ankara, Turkey.

E-mail: sy[email protected]u.tr. Tel: +90 258 296 3380. Fax: +90 258 296 3382.

Accepted 10 March, 2010

Geomechanical properties of natural stones have a crucial importance when stones are used for

constructing modern structures and buildings. Therefore, field and laboratory studies are indispensable

to investigate the stone quality for purposed structure. Denizli and Antalya surroundings in South-

western Turkey have large natural stone reserves and more than 80 quarries operated actually. They

export natural stones including various types of travertine, limestone, and schist to all around the

world. In this study, laboratory tests and field studies were carried out to investigate the quality of

construction stones quarried in the region. For the purpose of the study, stones including four type of

travertine, three type of limestone and two type of schist were collected from the quarries; and so,

laboratory tests including effective porosity, both dry and saturated unit weight, water absorption by

weight, uniaxial compressive strength, P-wave velocity, slake durability index together with thin section

analysis were performed in accordance with the international standards to explore the quality of stones

to be used for modern construction. Concluding remark is that physical and mechanical properties of

examined natural stones satisfies the relevant regulations (that is, an norms, Turkish and ASTM

standards) with some deviation to be used as construction materials.

Key words: Construction, stones, quality, South-western Turkey.

INTRODUCTION

Natural stones being used in both interior and exterior of

buildings are one of the most common construction

materials in the world. To be used as construction

materials, natural stones should have a good quality

according to their properties. In southwest Turkey,

various stones including travertine, limestone, and schist

are quarried and exported around the world to be used

for constructing modern structures. More than 50 quarries

extracting various type of travertine are operated in

Denizli surroundings (Figure 1). In fact, Turkey together

with several countries of the Mediterranean area (e.g.,

Greece and Italy), is exceptionally rich in travertine

deposits. Travertine including shrub, noche, reed and

crystalline crust (onyx) quarried in the Denizli Basin of

Turkey is one of the most common stone used for

exterior and interior of both historical and modern

buildings (Figure 2). The Denizli extensional basin in SW

Turkey has widespread carbonate deposit since Late

Quaternary.

Travertine color ranges from light through dark beige and

usually formed around hot and cold carbonate-bearing

springs. Travertine is simply a very pure and mostly

porous form of limestone. Besides that, two types of

schist stone were quarried in the Denizli Basin where the

country of Baklan and Bekilli is to extract natural stone as

construction material. In addition to that, dolomitic

limestone outcrops around the Country of Bozkurt in the

Denizli Basin, white soft limestone and crystalline

limestone, quarried in the countries of Elmali and

Korkuteli, respectively, in Antalya surroundings, have

been visited and then the stone samples were collected

to use for stone quality assessment. Several researches,

mainly related to hydrogeology of hot waters,

morphological classification and geothermal potential of

the Pamukkale (Hierapolis) region, have performed on

travertine deposits in the Denizli Basin (Kocak, 1971;

Esder and Yılmazer, 1991; Ekmekci, 1993; Ekmekci et

al., 1995; Hancock et al., 1999; Ozkul et al., 2002; Yagiz

Yagiz 751

Figure 1. Typical travertine quarry operated in the county of Kaklik in Denizli.

Figure 2. Historical place (Hasmetbaba tomb) constructed with travertine in Denizli.

et al., 2005).

Further physical properties of locally operated stone

quarries in the study areas, Antalya and Denizli

surroundings were investigated by different researchers

(Kilic and Yavuz, 1994; Cam et al., 2003; Yagiz and

Akyol, 2005; Yagiz, 2006, 2009). However, there is no

attempt made to investigate the properties of extracted

stones utilized for construction purposes in the region.

The purpose of this study is to clarify the links between

geomechanical properties (that is, physical and

mechanical) of construction stones and their quality to

use as construction and building materials. Therefore,

752 Sci. Res. Essays

Figure 3. Location map of the sampling sites in South-western Turkey.

field inspection in quarries and laboratory tests on

collected samples were carried out and then the attained

results were discussed herein.

MINERALOGICAL AND PETROGRAPHICAL

INVESTIGATION

In the first stage of the study, block samples were

collected from various quarries of travertine, limestone

and schist quarried in South-western Turkey (Figure 3).

After that, mineralogical and petrographical studies were

carried out on the prepared samples by using optical

microscope in accordance with EN 12407 (2002)

Standard. Travertine, from Quaternary to Neogene ages,

is one of the most common quarried stones in Denizli

basin. Travertine precipitated at different depositional

conditions shows variations of color, appearance,

bedding, porosity, texture and composition.

Travertine litho types in the basin mainly include shrub,

crystalline crust (onyx), reed and noche which are

compact, brownish colored and subunit of the reed type.

Shrub type travertine represented by small bush like

growths in the field is common deposit on horizontal and

sub horizontal surface in the basin (Chafetz and Folk,

1984; Pentecost, 1990; Gou and Ridding, 1998) as

shown in Figure 4a. Noche, that is a commercial name

for compact and dense reed type travertine is dark

brownish colored, dense and low porous (Figure 4b).

Reed travertine is one of the prominent elements in the

Denizli travertine deposited marsh-pool, mound and

self built channels (Figure 4c). The travertine is rich in

molds of reed and coarse grass were named reed (Guo

and Riding, 1998). The organic matter content and

porosity of the reed travertine is relatively higher than

others.

Crystalline crust travertine is commonly formed as a

result of rapid precipitation due to fast flowing water on

gentle slope. Dense, crudely fibrous and light colored

onyx is composed of elongated calcite feathers and

developed perpendicular to the depositional surface

(Figure 4d). Jurassic aged beige colored crystalline

limestone and Eocene aged white colored, fine grained

spary-calcite cemented limestone outcrops around the

countries of Elmali and Korkuteli in Antalya, respectively

(Figures 4e and f). Dark colored, medium to coarse

grained and massive Eocene age dolomitic limestone

outcrops around the country of Bozkurt in the Denizli

Basin (Figure 4g). Two types of schist outcrop around the

both countries of Baklan and Bekilli in the Denizli Basin

are categorized according to their petrographical and

mineralogical properties (Figures 4h and i).

The result indicates that mineralogical and

petrographical properties of stones together with

geomechanical properties have a significant affect to their

usage as construction materials.

MATERIALS AND METHODS

Using rock testing standards such as International Society for Rock

Mechanics (ISRM) and Norms of European Committee for

Standardization (EN), physical and mechanical laboratory tests

Yagiz 753

Figure 4. Photomicrographs of thin section analysis in cross polarized (×10); (a) Shrub type travertine has sparite micrite cemented

densely packed layered texture; (b) Noche type has sparite calcite cemented texture with low porous; (c) Reed type has sparite micrite

cemented relatively high porous texture; (d) Crystalline crust shows micrite and sparite layered texture; (e) Beige limestone shows micro

cracks and defects with sparite calcite cemented texture; (f) White limestone has sparite calcite cemented texture with micro fossils; (g)

Dolomitic limestone shows sparite and micrite cemented texture with healed joints; (h) Biotite schist has high biotite and quartzite

content along with schistose texture (i) Muscovite schist composed of quartzite, mica muscovite and some opaque with schistose

texture.

including effective porosity (n’), both dry and saturated unit weight

(γ

dry

, γ

sat

), water absorption by weight (w), uniaxial compressive

strength (UCS), P-wave velocity, elasticity modulus (E) and slake

durability index (Id

), were carried out to investigate the quality of

stones to make use of construction material. Before testing, rock

samples were carefully inspected to obtain the most representative

stone samples for performing those tests.

Further, as stone blocks and prepared samples have a natural

defect, weathered colour, cracks and other unwanted properties

that make stone weaker and different than reality, the result of such

tests was excluded and not used for the quality assessment.

Besides those tests, geomechanical properties of stone may be

evaluated by expanding the range and type of laboratory tests like

freezing and thawing, hardness and/or abrasiveness tests;

however, type and quantity of tests could be restricted with

available laboratory facilities and finance as herein. Physical and

mechanical properties of stone were examined using common

laboratory tests and accessible facilities in this study.

Consequently, following laboratory tests were performed on

those stone samples to evaluate the quality of the stones quarried

in South-western Turkey, where remarkably rich within travertine

deposits and other carbonate rocks such as limestone and

dolomitic lime in the Mediterranean area.

Physical property tests

Physical index properties including dry and saturated unit weight,

porosity, and water absorption were measured in the laboratory by

using the ISRM (1981a) standard testing methods. In order to

perform those index rock tests, rock samples within 70x70x70 mm

dimension were prepared. Further, the specimen volumes were

computed from an average of several caliper readings.

Dry weights of specimens were obtained with a balance,

754 Sci. Res. Essays

Table 1. Basic statistical distribution of measured stone properties in average with standart deviation.

Sampling

locations

Rock and

litology type

EN12670

Stone UCS

± SD

γγ

dry

± SD

γγ

sat

± SD

Remarks

Name (MPa) (km/s) (%) (%) (kg/m

) (kg/m

) (%)

Denizli/Kocabas 1 Shrub travertine Travertine 61 ± 20.6 4.8 ± 0.12 1.35 ± 0.46 0.55 ± 0.19 2427 ± 25.2 2440 ± 22.2 98.91 ± 0.10 Layered texture w/fine to medium size grain

Denizli/Kocabas 2 Noche travertine Travertine 64 ± 10.9 5.0 ± 0.08 1.59 ± 0.89 0.66 ± 0.38 2373 ± 48.1 2388 ± 42.1 98.55 ± 0.14 Compact texture, fine to medium grain size

Denizli/Kaklık Reed travertine Travertine 41 ± 16.6 4.5 ± 0.11 1.89 ± 0.50 0.80 ± 0.22 2318 ± 56.3 2336 ± 54 98.87 ±0.12 Porous cemented, fine to medium grain size

Denizli/Honaz Crystalline crust onyx 58 ± 15.0 4.7 ± 0.19 2.05 ± 0.88 0.76 ± 0.34 2663 ± 45.5 2684 ± 38.1 99.24 ± 0.07 Layered texture, with fine grain size

Antalya/Korkuteli Beige lime Limestone 82 ± 28.3 5.0 ± 0.17 0.16 ± 0.10 0.06 ± 0.04 2631 ± 8.4 2632 ± 7.9 99.43 ± 0.04 Micro cracks; medium to coarse grain size

Antalya/Elmali White lime Chalk 32 ± 3.70 3.8 ± 0.41 9.70 ± 2.20 4.24 ± 1.14 2267 ± 98.1 2362 ± 77.9 98.49 ± 0.25 White colored, fine grain size, with fossils

Denizli/Bozkurt Dolomite lime Dolomitic

limestone

92 ± 33.3 4.9 ± 0.29 0.60 ± 0.27 0.22 ± 0.10 2726 ± 33.6 2732 ± 31.8 99.65 ± 0.06 Healed joint, medium to coarse grain with

some calcite veins

Denizli/Bekilli Biotite schist Calc schist 98 ± 7.10 5.1± 0.44 0.74 ± 0.11 0.29 ± 0.04 2498 ± 41.8 2506 ± 42.8 n/a Greenish colored, fine to medium grain size,

biotite rich, schistose

Denizli/Baklan Muscovite schist Calc schist 114± 13.4 5.6 ± 0.32 0.43 ± 0.53 0.17 ± 0.21 2588 ± 71.8 2592 ± 66.8 n/a Yellowish colored fine to medium grain size,

muscovite rich, schistose

=average values and SD=Standard deviation;

EN 12670 refers to international name of investigated stones.

capable of weighing to an accuracy of 0.01 g. Dry and

saturated unit weights of rocks (γ) were obtained from the

ratio of sample weight to the volume in kg/m

and also, the

effective porosity (n’), pore volume and water absorption by

weight (w) was determined via saturation and caliper

techniques as suggested by ISRM (1981a). As a result,

relevant physical index properties of rock were obtained on

ten samples for each rock type, and so, the average values

of the relevant properties with standard deviation are

obtained as given in Table 1.

Uniaxial compressive strength test

The uniaxial compressive strength tests were carried out

on a sample having dimension of 70x70x70 mm, smoothly

sawed using diamond saws from large size blocks in

accordance with EN 1926 (2000) natural stone testing

standard. The ends of the samples were cut parallel to

each other and at right angle to the longitudinal axis and

then smoothened to ensure that the samples were free

from abrupt irregularities and roughness. The stress rate

applied uniformly within the limits of 0.5 - 1.0 MPa/s. The

tests were applied perpendicular to observed beddings or

layers on a sample to discount anisotropy affect. Total 10

samples were utilized for each rock type and the average

values of the test were recorded together with standard

deviation (Table 1).

P-wave velocity test

P-wave velocities of the specimens were measured using

the portable ultrasonic nondestructive digital indicating

tester (PUNTID plus). This tester measures the time of

propagation of ultrasound pulses in a sample in the range

(0.1 - 999.9 µs) with a precision of 0.1µs. The transducers

used were 42 mm in diameter with 54 kHz.

The measurements were carried out perpendicular to

visual beddings or layers by using good coupling agent

necessary between rock surfaces and both receiver and

transducer face for accuracy of measurement. Afterward,

P-wave velocity was computed from the ratio of distance

between transducer and receiver to the time that P-wave

takes to travel the distance. The tests were performed on

10 samples for each rock type by following ISRM (1981b)

testing standards and the average values together with

standard deviation were used in the dataset (Table 1).

Also, P-wave classification of studied stones was

categorized in accordance with Anon (1979) P-wave

classification. P-wave velocity of the stone ranges from

moderate to very high class in accordance with Anon

(1979), as tabulated in Table 2.

Slake durability index test

Slake durability tests developed by Franklin and Chandra

(1972) were carried out to examine the slake durability of

rocks as suggested by ISRM (1981c). To perform the tests,

the representative samples were selected comprising ten

rock lumps, each with a mass of 40 - 60 g to give a total

mass of 450 - 550 g. The sharp corners of the rock pieces

were rounded during the sample preparation to obtain

spherical shape.

After that, the samples were placed in a clean drum and

Yagiz 755

Table 2. Classification of natural stones based on P-wave velocity (Anon, 1979).

Vp (km/s) Description Shrub

type

Noche

type

Reed

type

onyx

type

Beige

lime

White

lime

Dolomite

lime

Bio

schist

Musco.

schist

<2.5 Very low

2.5-3.5 Low

3.5-4.0 Moderate x

4.0-5.0 High x x x x x x

>5.0 Very high x x

Table 3. Durability classifications of stones based on second cycle of slake durability test (Johnson and DeGraff, 1988).

(% )

Class Shrub

type

Noche

type

Reed

type

onyx

type

Beige

lime

White

lime

Dolomite

lime

Bio

schist

Musco.

schist

> 30 < 60 Very low

30 - 60 60 - 85 Low

60 - 85 85 - 95 Medium

85 - 95 95 - 98 Medium H.

95 - 98 98 - 99 High

> 98 > 99 Very high

According to Id

V. H. V. H. High V. H. V. H. High V. H.

According to Id

V. H V. H V. H. V. H. V. H. High V. H. n/a n/a

Table 4. Average slakes durability indices with standard deviations for stones after each cycle.

Shrub type

± SD

Noche type

± SD

Reed type

± SD

Onyx type

± SD

Beige lime

± SD

White lime

± SD

Dolomite lime

± SD

Biotite schist

± SD

Musco. schist

± SD

99.23 ± 0.08 99.25 ± 0.11 98.94 ± 0.12 99.53 ± 0.04 99.62 ± 0.03 99.00 ± 0.15 99.73 ± 0.06 n/a n/a

98.91 ± 0.10 98.87 ± 0.12 98.55 ± 0.14 99.24 ± 0.07 99.43 ± 0.04 98.49 ± 0.25 99.65 ± 0.06 n/a n/a

98.57 ± 0.11 98.59 ± 0.13 98.23 ± 0.16 99.05 ± 0.09 99.29 ± 0.07 98.03 ± 0.33 99.56 ± 0.06 n/a n/a

98.34 ± 0.12 98.32 ± 0.16 97.95 ± 0.19 98.86 ± 0.10 99.13 ± 0.05 97.62 ± 0.40 99.50 ± 0.07 n/a n/a

were dried to constant mass at a temperature of 105°C, generally

requiring 2 - 6 h in the oven. The masses of drum and samples

were recorded and the samples were then tested after cooling. The

lid was replaced, the drum mounted in the trough and coupled to a

motor. Further, the trough was filled with a tap water at 20°C, to a

level of 20 mm below the drum axis, and the drum rotated for 200

revolutions during a period of 10 min to an accuracy of 0.5 min as

recommended by ISRM (1981c). After that, the drum and retained

percentage of samples were dried to constant mass at 105°C. As a

result, the slake durability indices (Id) corresponding to each cycle

were computed as the percentage ratio of final to initial dry weights

of rock in the drum after the drying and wetting cycles. Although,

slake durability test recommended to continue till two cycle and its

result were classified in accordance with second cycle (Id

) by

Johnson and DeGraff (1988) in Table 3, the tests were performed

on ten sample for each rock type till four cycles as suggested by

different researchers (Gokceoglu et al., 2000; Yagiz, 2001; Dhakal

et al., 2002; Yilmaz and Karacan, 2005; Gupta and Ahmed, 2007;

Yagiz and Akyol, 2008; Yagiz and Zorlu, 2009).

Consequently, the average of slake durability indices with

standard deviation for each rock type were tabulated in Table 4.

Concluding remark is that the rock having lower value of slake

durability (that is, white limestone) exhibit the higher susceptibility

for degrading under relevant condition. The test could not be

carried out for two investigated schist, which are very hard and

almost impossible to make standard sample.

DISCUSSION

Natural stone properties including uniaxial compressive

strength, P-wave velocity, effective porosity, slake

durability, water absorption by weight and both dry and

saturated unit weight, were investigated according to the

ISRM and EN standards. To obtain the best representa-

tive value for each rock property, total 10 samples were

prepared, tested for each stone type and so the results of

those tests were discussed herein. Further, to evaluate

756 Sci. Res. Essays

Table 5. The quality of studied natural stones in accordance with the relevant regulations and classifications.

Stone properties

Shrub

type

Noche

type

Reed

type

Onyx

type

Beige

lime

White

lime

Dolomite

lime

Bio

schist

Musco.

schist

TS11143

(1993)

TS2513

(1993)

ASTMC97

(1990)

ASTMC170

(1990)

UCS (MPa) (tile flooring) 61 64 41 58 82 32 92 98 114 >50 - - >52

(For wall covering) 61 64 41 58 82 32 92 98 114 >30 - - -

dry

(kg/m

)

2427 2373 2318 2663 2631 2267±98 2726 2498 2588 >2300 - >2305 -

w (%) 0.55 0.66 0.80 0.76 0.06 4.24 0.22 0.29 0.17 <3 <7.5 <0.2 -

n’(%) 1.35 1.59 1.89 2.05 0.16 9.7 0.6 0.74 0.43 - <12 - -

Class High High High High V. High Moderate

High V. High

V. High

- - - -

Durability (Id

) V. High V. High High V. High V. High High V. High n/a n/a - - - -

*TS11143 standard for travertine as building stone and TS2513 standard for natural stone as building stone.

the quality of studied rocks as construction and

building materials, European committee for

standardization, Turkish and the American society

of testing materials (ASTM) standards were consi-

dered. Also, P-wave velocity and slake durability

classification were made for examined rocks as

recommended by Anon (1979), Johnson and

DeGraff (1988), respectively. It is found that the

physical properties of investigated stones are

good enough to be used for construction and

buildings in accordance with the EN, Turkish and

ASTM standards (Table 5). However, effective

porosity of travertine types does not give promise

result according to the ASTM standard that counts

travertine as marble.

In fact, effective porosity range that recom-

mended in the ASTM is actually impossible for

travertine that is more porous and weaker than

marble. So, travertine was categorized in detail

according to their origin in TS 11143 (1993) and

named as travertine via using the EN 12670

(2004) standard. Therefore, such a variation

between utilized standards for stone investigation

is likely. In this study, some commonly measured

physical and mechanical properties of mentioned

stones were investigated as given earlier;

however, it is always possible to expand the type

and number of test to conduct on a sample as

considering usage purposes. So, this research

may also be extended by performing some other

laboratory tests to examine the quality of the

stones.

Conclusion

In this study, an extensive laboratory tests were

carried out on several types of stones quarried in

South-western Turkey to attain the goal of the

research. Relevant European norms, Turkish and

ASTM standards have been used for investigating

the quality of natural stones for construction and

building purposes. According to the obtained

results, investigated natural stones are acceptably

compact, strong enough and their resistance to

slake durability is high. They do not show any

weathering indication, micro cracks, weakness

plane or veins that make natural stones weaker

than expected. As a result of the study, it is

concluded that the natural stones quarried in

South-western Turkey could be used as

construction material in accordance with followed

regulations with some deviation; however, stones

used for construction should be selected by

considering the both climate feature of stone

usage region and usage purpose, otherwise,

mislead is inevitable.

ACKNOWLEDGEMENT

The author thanks to the local companies giving

logistic support during the field works. Also special

thanks to both Dr. Mehmet Ozkul and Tamer

Koralay of Pamukkale University for assisting on

the petrography studies of rocks.

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