Structural Analysis of Historical Constructions - Modena, Lourenço & Roca (eds) © 2005 Taylor & Francis Group, London, ISBN 04 1536 379 9

Durability aspects of masonry stones used in the southern temple wall in Jerusalem

I. Wasserman National Building Research Institute, Technion, Haifa, Israel

ABSTRACT: A swelling bulge that reaehed 0.71 m, approximately, has reeently appeared in the Southern Wall of the Temple Mount Area in Jerusalem. In Oetober 2002 the swelling rate was about 5 mm per annum. The properties of the masonry materiaIs in the Southern Wall were unknown. Therefore, the eurrent study has been essential and helpful for maintenanee and the planned conservation measures ofthe Southern Wall. The current study established that the works done in the Southern Temple Wall in Jerusalem in the first half of XX century could be referred as repair anel not conservation measures. Apparently, during their mandate, the British made repairs using inappropriate materiaIs. The discrepancies in material performance between the "original" and "new" masonry seems to have led to the appearanee ofthe bulge in the Southern Temple Wall.

INTROOUCTION

The current study was carried out in eollaboration with the Israel Antique Authority (IAA) and aimed at clar­ifying the causes of a swelling bulge that has recently appeared in the Southern Wall of the Temple Mount Area in Jerusalem. In October 2002 the maximal bulge monitored by IAA, reached 0.71 m, approximately, whereas the swelling rate was about 5 mm per annum.

Archival documents that were published in 1860's and have been kept in the IAA, have shown an obvious deterioration and splitting ofthe masonry stones in the Southern Wall at that time (Warren & Condor 1881). Therefore, restoration measures have been imple­mented since then. However, the available arehival documents have not included the detailed conserva­tion plans. Therefore, this writer could not determine where the abovementioned reeonstruction was carried out. Moreover, the properties of the stones and mor­tars in the Southern Wall were unknown. Therefore, the current study ofthe historic masonry materiaIs has been essential and helpful for maintenanee and the planned eonservation measures ofthe Southern Wall.

2 HISTORIC BACKGROUNO OF THE TEMPLE MOUNT COMPLEX

The Jewish Temples were partieularly deseribed in the Old Testament.

The Temple Mount Complex was destroyed along with the eity by the Roman general Titus in A.O. 70.

Since this time Jewish people have not used the Complex as a place oftheir religious cult.

Since the Mediaeval period the Complex was used by Muslims as a Holy place of Islam. Ouring that period, the leveI raising and the construction of the Dome of the Roek and the EI Aksa Mosque were earried out.

3 ENGINEERING BACKGROUNO OF THE TEMPLE MOUNT COMPLEX

Generally, the Southern Wall eonsists oftwo parts:

(a) An internaI part built during Herod 's period (37- 4 B.c.).

(b) An externaI masonry part, about 1.2 m wide. This wall was constructed later then Herod's period. However, the exaet term of its construction is still unknown.

The samples of historie materiais investigated in the current research were bored only from the externaI masonry part.

According to calculations done in the Teehnion and the eleetromagnetie tests , the Southern Wall at its west­ern corner is about 4.5 ± 0.5 m wide (Weisman 1968; Ben-Oov 1985; Mazar 1989; Peretz 1991).

4 OLO MASONRY PRACTICE IN ISRAEL

Sinee aneient times, a common building praetiee in Israel was masonry eonstruction with sufficiently hard

245

and unblemished dimension stones. These dimension stones were set in eourses fitted a desired design­ing height. Usually, a stone eourse in masonry walls was 0.5 to 1.5 m high (Peretz 199 1; Sparai & Sason 2001). There was a eornrnon praetiee in aneient quar­ries loeated near Jerusalem, to hew the dimension stones about 35 to 55 em long. The height and the width of sueh stones was about 20 to 30 em (Sparai & Sason 200 1).

In the Jerusalem area, soft ehalks were also widely used in masonry eonstruetion. However, one should keep in mind that there was a widespread phenomenon of hard and dense ealcrete formation oeeurring in the Israeli soft ehalks (Buehbinder (1969)). Calerete eould be deseribed as a natural eonerete in whieh a mieritie matrix eonsisting of ealeium earbonate as eement, binds together pebbles, sand and desert debris (Judson & Riehardson 1995).

Calcrete layers might be as deep as 1.5 to 2.5 m from the earth surfaee (Talesnik et aI. 200 1). The soundness of ealcrete is mueh poorer than of unweathered soft limestone.

Wood and ehareoal were universally used as fuel in the limestone kilns in the past. Therefore, wood ash and eoal dust are eornrnon impurities observed in historie lime mortars and Roman eoneretes (Tsatskin 1999; Tsatskin et ai 2000; Heritage Lottery Fund 2000; Sidda1l2000; Krumnaeher 2001).

5 GENERAL BACKGROUND OF THE LIMESTONE DURABILITY

Durability of limestone is strongly dependent on its ehemieal and mineralogieal eomposition (Dana 1993) and the eontent of the seeondary minerais. (Winkler 1982; Winkler 1997; lare et Mitrie 2000). The smaller the eontent of the seeondary minerais in limestone; the longer durability. Iron in the form of ferrie iron, Fe3+, is the most eornrnon and the strongest pig­ment in limestone (Winkler 1997). In limestone ferrie iron, Fe3+ , is usually presented as hematite, Fe20 3, goethite, Fe3+00H, and amorphous eornrnon rust, Fe203 . nH20. Obviously, hematite is a mueh more sta­ble mineral than goethite (Rezaie-Serej & Cook 1988; Oh et aI. 1998; Cook et aI. 1999). Stability of goethite is strongly dependent on aeidity, pH. This mineral is stable only in a basie non-salty environment (pH 2: 10). Aeeording to (Park 1978), the rains in the Eastern Mediterranean have an average pH of 5.5. The eontaet of goethite with aeid rain water in the presenee of ehlo­rine ions, Ci- , promotes the formation of akagaenite, Fe2+0(OH)CI, instead of hematite, Fe203 (Rezaie­Serej & Cook 1988; Oh et aI. 1998; Cook et aI. 1999; Stahl et aI. 1998). This proeess aeeelerates formation of the eommon amorphous rust in limestone, while a volume inerease that oeeurs during eonversion of

goethite to rust eould be 20% to 70% (Winkler 1997). Thus, limestone that eontains goethite and ehlorine ions might deteriorate and even erumble.

Aeeelerated weathering and deterioration of lime­stone in polluted environments is an aeute eommon problem of aneient and historie struetures throughout the worId (Winkler 1982; Torraca 1988; Moroni & Poli 1988; Johansson et aI. 1988) .

6 EXPERIMENTAL

6. I Materiais

Four stone fragments and two morta r pieees were drilled off from a eentral part of the swollen area in the externai masonry part of the Southern Wall. The deseription ofhistorie materiais is given in Table 1.

6.2 Tests

The eharaeterization methods used in the eurrent investigation were:

(A) Chemieal and mineralogieal analysis ofthe his­torie stones - X-ray fluoreseenee (XRF); - X-ray diffraetion (XRD); - petrographieal investigation with polarizing

mieroseope; - quantitative wet ehemieal analysis.

All the abovementioned test proeedures are deseribed in details in Dana 1993.

(B) Physieal properties of the historie stones - bulk density and tota l absorption (ASTM C97

1990); - eapilIary absorption (EN 1925 1999) and eap­

illary absorption eoeffieients; - degree of saturation was ealculated as a ratio

of the eapilIary absorbed water and the totalIy absorbed water;

Table I . Referring of the tested archaeological materiais.

Name ofthe Location in the archaeological southern Length, sample temple wa ll m

Stone I Near externai surface 0. 1 Stone 2 From the edge of 0.28

Stone I toward the internaI part ofthe Wall

Stone 3 From the edge of 0.22 Stone 2 toward the internaI part of the Wall

Stone 4 From the edge of 0.58 Stone 3 toward the internaI part ofthe Wall

Mortar Masonry joints

246

- water evaporation rate (Wasserman & Bentur 2004). The measurements were carried out for the samples used in the capillary absorption test;

- Microerosion meter Digimatic Indicator IOF-150, Mitutoyo Corp., Japan was used in the stone swelling test (see Fig. I). The microero­sion meter is a simple micrometer tool that gauges surface height at a number ofpredeter­mined points, rei ative to initial datum points set into the stone (Price 1996).The test procedure used in the current research was as following: • oven-drying of the stone samples at tem per­

ature of 105 ± 3°C to constant weight; • cooling at temperature of 21 ± 3°C; • water immersion of the stone samples for

24 hours. The changes in height of the sam­pIes were monitored. Mean swelling per unit height was calculated for each stone sample.

(C) Mechanieal properties - compressive strength (ASTM C I 70 1990).

Samples used were 50 x 50 x 50 mm or 40 x 40 x 40 mm. Stone samples were oven­dried for 24 hours. Some samples were water saturated. Because ofthe Iimited amount ofthe investigated historic materiaIs, the statistical processing of the strength data was not carried ou!. The results presented in this paper are given in the form of the minimal and maximal val­ues of the strength. Compressive strength was measured in two directions:

(a) in parallel to the principal axis of the core drilled from the Southern Wall (sub­sequently referred to as A-A);

Figure I. Image of swelling test with Digimatic Indicator IOF-ISO, Mitutoyo Corp. , Japan.

(b) transversely to the principal axis of the drilled core (subsequentJy referred to as B-B).

- wear resistance (220 rotation cycJes) (Israel i Standard SI 6 1999).

(O) Charaeterization ofmortar Additional tests were carried out to character­ize the chemical and mineralogical composition and the physical properties of two mortar pieces drilled offtogether with the Stones ' samples.

7 RESULTS

7.1 Chemical and mineralogieal analysis of lhe historie stones

7.1. I Elementa/y analysis (XRF) The main element identified in ali investigated sam­pIes was calcium, Ca. In ali investigated materiais there were determined traces of silicon, Si, iron, Fe, and sulfur, S, which were presented in minor amounts. Potassium, K, and chlorine ion, CI - were detected in small amounts in the Stone 3, Stone 4 and in the mortars. The results of semi-quantitative estimation of secondary (impurity) elements in the Stones is presented in Fig. 2.

It could be suggested that the investigated stones might be classified into two groups: Stone I & 2 and Stone 3 & 4. Within each group, the occurrence of the secondary elements is similar; however, these two groups are quite dissimilar.

7.1.2 Mineralogieal eomposition (XRD) The ma in mineral in ali investigated materiaIs is cal­cite, CaC03 . In X-ray diffraction ofall samples there were determined small peaks of goethite, FeH O(OH). The results of X-Ray diffraction proved the classi­fication of the Stones in two groups: Stone I & 2 and Stone 3 & 4. The former group contains a high rate of impurities, whereas, the latter group, on con­trary, is characterized by slight traces ofthe secondary constituents.

7% r-------~------~--------~------,

• . [<lCI.K -----------,------------,----------_. · . · . O Si OS

--------:-----------. DF.

_______ J. __________ .'. __________ _

· . · . -----'------ ______ 1 ______ ------

----..,-- ---- ------,--- ---------· .

Figure 2. Presence of impurities in historie stones from lhe southern temple wall (XRF analysis).

247

7.1.3 Mineralogieal eomposition (petrographieal investigation with polarizing mieroseope)

The stones studied in the current investigation could be defined as weathered soft micritic calcite covered with an adjacent iron oxide impregnation, possibly of goethite, Fe3+0(OH). lt was found that Stone I is much harder than the other stone samples. Ali stones are partly transformed into calcrete. In contrast to the other samples, Stone 4 is far less weathered, and is transformed into calcrete to a smaller extent (see Fig. 2). There are minor amounts ofadjacent iron oxide impregnation, probably goethite, in this stone.

7.IA Quantitative ehemieal eomposition of historie stones

Average chemical composition of Stone I & 2 and Stone 3 & 4 are reported in Table 2. As was previously emphasized, Stone I & 2 contains a high amount of impurities, while Stone 3 & 4 is more homogeneous.

25 r-----~----~--~----~----~

- - - - - - - ~ - - - - - - - ~ - - - - - - - .... - - - - - - - - ,- - - - - - - -.. ~ - .. - .. -~ .... - - - ~ - - -- -: - --

o~----~----~--~----~----~ o 2 3 4

Time, hours l12

Figure 3. Capillary water absorption ofhistorie stones.

Table 2. Chemieal eomposition ofthe historie materiaIs.

Component

CaO (total) CaO (soluble in HCI) Insoluble residue Si02

AI20 3

Fe20 3 MgO Na20 K20 total K20 soluble in HCI CaO free LOI Organie material Cl - (estimated by content of soluble alkali s)

Content, % (weight per cent)

Stone I & 2

45.9 45 .7

8.5 5.1 0.9 0.45 0.9 1.0 0.49 0.44 0.02

40.6 0.7 1.46

Stone 3 & 4

52.4 52.4 2.8 1.2 0.9 0.3 0.5 0.04 0.12 0.12

< 0.01 42.3

0.5 0. 13

It could be concluded that the high content of sec­ondary mineraIs and the advanced rates of natural aging ofStone I & 2, as well as their transformation to calcrete to a greater extent then Stone 3 & 4, indicates the potential differences in the durability of the two investigated groups of stones.

7.2 Bulk density, total water absorption and saturation eoeifieient

The results are given in Table 3. Stone I and Stone 2 are similar in their physical

properties. However, they are eminently different from Stone 3 and Stone 4. Moreover, Stone I and Stone 2 are much denser than Stone 3 and Stone 4, which have similar physical properties.

7.3 Capillary water absorption of historie stones

Fig. 3 presents the results of the capillary water absorption.

Capillary absorption coefficients ofthe investigated historic stones:

Stone I - 9 kg per m2 per hour l/ 2 ;

Stone 2 - 12 kg per m2 per hour l / 2 ;

Stone 3 - 18 kg per m2 per hourI/ 2 ;

Stone 4 - 21 kg per m2 per hour l / 2 .

Ali investigated stones are characterized by a very quick rate of water absorption. Capillary water uptake of Stones 3 & 4 is approximately as much as, that of Stones I & 2.

7A Evaporation rate ofhistorie stones

The results of the evaporation test carried out at 20°C/55% RH are presented in Fig. 4. Similarly to other properties, evaporation ability of Stone I & 2 strongly differs from Stone 3 & 4. Stone 3 & 4 have higher rates ofwater evaporation. High water evapora­tion capacity is very important for Iimestone durabi lity, which is strongly affected by the moisture entrainment in stone.

Table 3. Bulk density and total water absorption of the historie stones.

Oven-dried Total water bulk density, absorption, %, Saturation

Material kg/m3 (weight per eent) eoeffieient

Stone I 1,990 13 0.83 Stone 2 1,96 1 16 0.79 Stone 3 1,500 2 1 0.94 Stone 4 1,44 1 27 0.92

248

7.5 Swelling and swelling rate ofthe historie stones

Swelling due to moisture was measured only for samples Stone 2, Stone 3 & Stone 4. Swelling of Stone I was not eheeked beeause ofthe limited amount

(a)

-" ~~~ ~ ~ o ~ ~ ~ 0'0" _ c N

..c I': t:

.:.0..; "-v "'O ~ E.ll

j]~ .ll H . ~

'" ~ o

(b)

. , , .L __________________ , ___ .I _________ _

....... Stone 1 : : : -,...- - ----------------,---,----- ----

-- . Stone 2 _ ~ _________________ .:. __ ~ _ . a . '". ~_-_ ~ _

... Stone 3 _ ~ ___ .. ___________ .. __ :_ .. _ ~: . ". _______ _

_Stone4 - ~ -- - ------------, I , I ------- - --,---,-- -- -- ------- - - ---,- - - , - ----------

·· ··· ····;···f ··· ~_!I':. -:- - ~ .~ .. -:':~.~ ..

90%

80%

70%

60%

50% 40%

30%

20%

10%

0% o

234 678 Time, hour ' 12

10 11 12 13

- - - - ·~Stone I .- -- - -- -- - - - --. -... - -.. - ...... . e . -- -- _ . .... ,SlOne 2 - --- - -. - - - .. _ L - --~ - -- --

- - - - . .... Stone 3 _ .... - - ;. . .. . ". - - - .. - - - - - ~ - - - - -

- -- - · _____ Stone:4;~: ~- ;.,;..- .--. ------ _ .. -----------,-----

24 48 72 96 120 144 168 Time. t. hour

Figure 4. Evaporation rate of historie stones. (a) evapora­tion rate ofhistorie stones at 20°C/55%RH; (b) ratios between weight ofwater evaporated at different periods and weight of water absorbed during a 24 hour period.

Table 4. Swelling eharaeteristies ofthe historie stones.

Stone 2 Stone 3

Swelling, Swelling Swelling, Time, .6.Sw, rate, (SwR), Time, .6.Sw, .6.t, x 10- 6, x 10- 6 , m per .6.t, x 10- 6 ,

hour mperm m per hour hour m perm

0.0 O O O 0.08 0.015 0.18 0.08 0.09 0.33 0.015 0.04 0.33 0.15 0.83 0.000 0.00 0.83 0.18 1.33 -0.103 0.08 1.33 0.21 1.83 -0. 133 0.07 1.83 0.24 2.83 -0. 163 0.06 2.83 0.30 3.33 -0.207 0.06 3.33 0.30 3.83 -0.237 0.06 3.83 0.30 20.83 -0.237 0.01 N/A N/A 24.00 -0.266 0.01 23.83 0.36

available. Swelling due to moisture was caleulated as a ratio between changes in the height of moist sample at time t and its initial height ( x 10- 6 m per m per) after oven-drying and eooling. The results of measurements are shown in Table 4. Swelling rate was estimated as swelling at time unit (x 10- 6 m per m hour), i.e.:

(SwR) = ~Sw, , ~t

(I)

where (SwR), = swelling rate at time t, x 10- 6 ,

m perm per hour; 6,Sw, - swelling at time t, x 10- 6 ,

m per m; 6, t - time, hour. Fig. 5 is presents the swelling kineties. As the test was earried out at eonstant tempera­

ture and humidity, the reduetion in swelling during the test pinpointed the dissolution of some mineral eompounds from the surfaee of the historie stones.

7.6 Compressive strength of historie slones

Compressive strength ofthe oven-dried historie stones is plotted in Fig. 6.

0.4 .............. , .... , .... , .... , .... , ... .

~~ 0.2 ~;.' ••. ; .... ; .... ! .... ! .... ! .... ~ ... . o ' __ ,

-;:; 0.0 t'ot-;...' _ .... ..:....,;'''''''~--;.--;...-....;...-...;....--1 Time. hours

1.0.2 .~ ... ~ .~.~~.:-, I ~ .. . . '?. .. ~ .... : I .... ;;, I I , ...... , I

, I , , I ..... ' I

·0.4 - - --~ - - - - ~ - - - -. - - - -. - - - - ~ - --~- - - - .... - - - --, .... , _ Stone 2 Slone 3 _ Stone 4 , ...... ,.-. -.

·0.6

Figure 5. Swelling ofhistorie stones eaused by moisture.

Stone 4

Swelling Swelling, Swelling rate, (SwR), Time, .6.Sw, rate, (SwR), x 10- 6 , m per .6.t, x 10- 6 , m per x 10- 6 , m per m per hour hour m hour m per hour

O O O 1.09 0.08 0.16 1.88 0.45 N/A N/A N/A 0.22 N/A N/A N/A 0.16 1.25 0.24 0.19 0.13 1.75 0.22 0.12 0.11 2.25 0.20 0.09 0.09 3.25 0.10 0.03 0.08 N/A N/A N/A N/A 21.00 -0.51 0.02 0.02 23.00 -0.55 0.02

lnitial maximal swelling rate lnitial maximal swelling rate lnitial maximal swelling rate x 10- 6 , m per m per hour -0.2 x 10- 6 , m per m per hour -1. 1 x 10- 6 , m per m per hour -1.9

249

30,-----~----------~----------------__.

25

. 20 "-::;:

~ 15

~ ~ iO

(a)

, , Scction A-A - perPendicular 10 drill dinlct ion -------- - ---:-------------:------------, , _____ _ _ ___ _ .:. _____ __ __ __ ~ EJ Minimal value

15 : O Maximal value ------------- - -,

Stane I (3 samples) $tone 2 (2 samplcs) $Ione 3 (2 samplcs) Stone 4 (3 samples)

30 ,-------------------------------------,

25

~ 20 ::;:

~ 15

~ ~ iO

Section B-B - parai lei to drill dircclipn _ _ _______ : ____ _ __ )<! ___ ~ ________ __ elM inimal valuc _

_~ ___________ o Maximal "alue _

5 - - - - - - - - - - - - :--No! 3vailablc

(b) Slone l $Ione 2 (2 samplcs) Stone 3 (2 samples) Stone 4 (2 samples)

Figure 6. Compressive strength of the oven-dried historie stones: (a) transverse to the principal axis ofthe drilled core; (b) parallel to the principal axi s of the drilled core.

Compressive strength ofwater-saturated stones was measured only for samples Stone 2 and Stone 4, because of limit in the amount of Stone 1 and Stone 3. Compressive strength of water-saturated stones, as well as a wet-to-dry strength ratio are given in Table 5.

7.7 Wear resistance

The results of abrasion test are shown in Fig. 7. Wear properties ofStone I & 2 and Stone 3 & 4 are different. Stone 4 cracked during the test.

7.8 Mortar characterization

The results ofthe mortar investigation were discussed in Wasserman 2003. No residues of bumt wood or charcoal dust were observed in the investigated mortar. Therefore, quicklime used in the manufacturing ofthe mortar drilled offthe Southem Wall has been calcined in an oil-based fumace.

8 DISCUSSION

All tests that were carried out showed the gap between the properties of Stone I & 2 and Stone 3 & 4. The differences in the mineralogical and chemical

8 - - - - - - - - - - - - - - - - - - - - - - -,--

3.8 ,

2.7 --- ;..:.:...:.: ----,---

---,---

---,---Not available

(cracked) :::n::: O~~ __ L-~~ __ -L-4 __ L-~ __ +-______ ~

Stone I Stonc 2 Slone 3 Stone 4

Figure 7. Wear resistance of historie stones.

compositions and in the character of water absorp­tion and evaporation of these two groups of the stones caused their dissimilar physical and mechanical behavior.

The total absorption of Stone 3 & 4 is about 1.6 times more than that ofStone 1 & 2. The differences in the capillary absorption are also very sharp. However, the kinetics ofthe water absorption is very similar. This fact is well correlated with the similarity of the satu­ration coefficients. Therefore, the investigated stones have a similar ratio of capillary pores available for moisture uptake, whereas the total amount of absorbed water is less in Stone 1 & 2.

The character of evaporation kinetics of these two groups of stone allows us to assume that Stone 1 & 2 has less water evaporation capacity than Stone 3 & 4. Higher water retention of Stone 1 & 2

Swelling and wear characteristics are very valuable for clarifying the trends in stone decay. The results of swelling and wear tests carried out in the cur­rent research, correlated very well with the capillary absorption of the stones. A relationship between the capillary absorption coefficients, the initial maximal swelling rates and the wear resistance of the investi­gated historie stones are shown in Fig. 8 and Fig. 9, respectively. The relationships shown in Figs. 8- 9 are ofhigh significance, e.g.:

(a) The correlation between the capillary absorption and swelling of Stone 2, 3 & 4 is described by the following equation:

SwRinitial = 6.3 . 10-6 . \V' 2 (2)

where (SWR)initiaI - initial swelling rate, x 10- 6 m per m per hour; W - capillary absorption coeffi­cient, kg per m2 per hourI/2 .

Therefore, swelling rate of Stone 1 could be estimated as 0.06 x 10- 6 m perm per hour, approximately.

(b) the equation describing the correlation between the wear resistance of the stones and their capillary absorption is as follows:

Wcar220 = OA'W - 1.3 (3)

250

~ 2.5 .--~--~--------------, -a- Slone 1 (cslimaled

~ swelling) E 2.0 • SlOne 2

~ E

'9 1.5 ::: <

~ 1.0

'" o

~ 0.5

. ]

... Stone 3

;:t:: Stone 4

- Masler curve

y = (6.3. 10.6) • x4.16

R2= 1.00

I , ''' I ,

. - - - r - - - - • - ... - - - - ? - - - - - - ~ - - - - - -

I I I ,

, " , " , "

:§ 00 -1'9 =---;.\\----;\3---\:-5 --\.;..7---;.\9----;2-\ ----l23

CapilJary absorption coeffcient. kg per m2 per hour1n

Figure 8. Relationship between eapillary absorption and swelling due to moisture of the investigated historie stones.

.x

~6 _~?~~~:~3 __ i _____________ : ____ ------. E~-\ --------~ : : • Slone 2

3 - - - - - - - • - - - I ____________ :. _________ ... Stonc 3

I I X Stone 4 (estimated)

- Master curve

o+------;.----~---~----~ 5 \0 \5 20 25

Waler absorption coefficie nt. kg per m2 per hourl r.!

Figure 9. Relationship between eap illary water absorption and wear resistanee of historie stones.

~ 2.0

1C E 1.6

E ? ~ 1.-

<

~ 0.8

'" ~ 0.4

]

• Slonc I

• Slonc 2

• Slone 3 )K Stone 4

- i-- --- ~ y =0.OO3x 3. 16 --~--I R2 = 1.00 I

---,------

I " I

- Master curve - ~ - - - - - - ~ - • - - - - ~ - - - - - ~ - - - - - - ~ - - - - - -I I I I , , , , ,

I I I I I I - ----r------r- -- ---T------ ------,.------.,------I I I I I I , , , , ,

~ ------~ ------ ~ - -- -- - ~ ------I I I I

I I I I

:§ 0.0 -i===--.----;---.---_---r---r---~

Wear (220 cyeles), mm

Figure 10. Relationship between the wear and lhe swelling of hi storie stones.

where Wear220 - wear resistance (220 cycles), mm; W - capillary absorption coeffieient, kg per m2 per hour I/2 .

The reliability ofmeasured and estimated results of swelling and wear characteristics could be proved by their high consistency, which is presented in Fig. lO.

The correlation between the results could be pre­sented by the following equation:

SwRinitiaI = 0.003 • (Wear12ol16 (4)

251

where (SWR)initiaI - initial swelling rate, x 10- 6 m per m per hour; Wear220 - wear resistance (220 eycles), mm.

The results shown in Figs. 8- 9 and the equation (2)­(3) confirm a strong impaet of moisture on the decay of chalks used for the erection ofthe South Temple Wall. However, the decay ofStone 3 & 4 caused by moisture might have been developed to a greater extent than Stone I & 2 .

Consequently, the vast differenees in the swelling eharacteristics of Stone I & 2 and Stone 3 & 4 might have effected in the differential behavior ofthe externai and internai parts of the Temple Southern Wall and resulted in pushing off the stiff externaI layer by the bulging internaI stratum.

Beeause ofthe dense structure, Stone I & 2 are ehar­acterized by much higher strength values than Stone 3 & 4. Consequently, Stone I and Stone 4 have the highest and the lowest strength values, respectively. Stone 2 and Stone 4 show the big difference between the strength observed in counter-cross directions, i.e.: the strength ratios in the counter-cross directions are about 1.4 and 1.9 for dry Stone 2 and 4 , respectively. Therefore, anisotropy of Stone 2 and 4 could be sug­gested. Contrary, the strength ratio in the counter-cross directions ofStone 3 was 1.0. Therefore, the difference between Stone 3 and Stone 4 could be confirmed.

It should be emphasized that lhe total water absorp­tion of Stones 3 is half as mueh as the total water absorption of Stone 4. Furthermore, the character of swelling is different in these two Stones, i.e. Stone 4 dissolved in a short period afler water immersion; whereas, Stone 3 was swelling eontinuously during the experiment; see Fig. 5.

The eumulative length of Stones 1 & 2 is about 38 em and of Stone 3 & 4 - 80 em (see Table 1). The properties of Stone 1 and Stone 2 are very similar. In contrast, Stone 3 and Stone 4 have different total water absorption, various swelling behaviors and dissi mi­lar meehanieal behavior in eounler-erossed direetions. Therefore, Stone I & 2 seem to fit one dimensiona l stone block in the Southern Wall , and samples Stone 3 and 4 might have fitted the two next bloeks behind the bloek of Stone I & 2.

Keeping in mind the similar mineralogieal eompo­sition of Stone 3 & 4, we can eonelude that Stone 3 & 4 might have been quarried at lhe same time from the same rock deposit and were used for lhe eonslruetion of the Temple Southern Wall at the same historieal epoch. However, Stone 1 & 2 have properties, whieh are very unlike Stone 3 & 4. Therefore, it has to have had a differenl provenanee. More eomprehensive researeh has to be done to eonfirm this suggestion.

As was previously emphasized, quicklime used in the manufaeturing ofthe mortar drilled offthe South­ern Wall has been ealeined in an oil-based furnaee . The use of this type of furnaees in the Israel lime industry

began in the 1920s during the British Mandate estab­lishment (Sasson 2000). Thus, it could be suggested that the investigated mortar is about 80 years old. The writer received an information from the Israeli Antique Authority regarding the repair work carried out by the British Mandate in the Southern Temple Wall in the 1930s after a strong earthquake which occurred in the region in 1927 and which caused the destruction of many structures in Jerusalem (Amiran et aI. 1994). Thus, it could be suggested that the Southern Temple Wall was repaired in the 1930s- 1940s. Unfortunately, the properties of the stones, which were used for this repair (e.g. Stones 1 & 2), were strongly different from the historie masonry in the Southern Temple Wall (e.g. Stones 3 & 4). Therefore, the performance of the new and the historie masonry in the Southern Temple Watt was different during att the time after repair. Conse­quently, the bulk spot that appeared in the Wall might be a result of this dissimilar material performance.

9 CONCLUSION

The compatibility of materiais used for conservation purposes is a well recognized prerequisite of the main­tenance and rehabilitation of any historie building. However, the importance of the implementation of compatible material was recognized only after the adoption ofthe Venice Charta in 1964. The works done in the Southern TempIe Wall in JerusaIem in the first haIf of XX century could be referred to as repair and not conservation measures. Apparently, during their mandate, the British did repairs using inappropriate materiaIs. The discrepancies in material performance between the "original" and "new" masonry se em to have Ied to the appearance ofthe bulge in the Southern Temple WaII.

REFERENCES

Amiran, D.H.K. , Arieh, E., Turcotte, T. 1994. Earthquakes in Israel and Adjacent Areas: Macroseismic Observations since 100 B.C.E. Israel Exp/oration Journa/44 : 290- 305 .

ASTM C97 1990. Absorption and bulk specific gravity of natural building stone.

ASTM C 170 1990. Compressive strength of natural building stone.

Ben-Dov, M. 1985.ln the shadow oftheTemple: the discovery of ancient Jerusalem (translated from the Hebrew by Ina Friedman), Keter Pub. House, lerusalem.

Buchbinder, B. 1969. Geological map of Hashephela region, [srael, with explanatory notes, Part [- 2, Jerusalem.

Cook, D.C., Oh, S.J., Balasubramian, R., Yamashita, M. 1999. The role of goeth ite in the formation of the protective corrosion layer on steel. Hyperfine Interactions, [22 (I): 59- 70.

Dana, J. D. 1993. Manual of Mineralogy. 2 1 st Edition, John Wiley & Sons, [nc., NewYork.

EN 1925, 1999. Natural stone test methods - Determination of water absorption coefficient capillarity.

Heritage Lottery Fund 2000. Limestone Heritage Project: Limekilns. Programme Report. Published by Arnside/ Silverdale Area ofOutstanding Natural Beauty, UK.

larc , S. & Mirtic, B. 2000. The Study ofWeathering Effects on the Slovenian Limestones by SEM. Journa/ of Con­ference Abstracts, 5(2): 553, Cambridge Publications.

Johansson, L.-G., Lindqvist, O., Mangio, R.E. 1988. Corrosion of Calcareous Stones in Humid Air Conta in­ing S02 and N02. Durabi lity of Building Materiais, 5: 439-449.

losephus Flavius 1984. The Jewish Wars. Penguin Clas­sics (translated by G.A. Will iamson, revised by E.M. Smallwood).

Judson, S. & Richardson, S.M. 1995. Earth: An Introduc­tion to Geologic Change, Englewood Cliffs, Nl, Prentice Hall.

Krumnacher, P.J. 200 I . Lime and Cement Technology: Tran­sition from Traditional to Standardized Treatment Meth­ods. Thesis (M.Sc.). Virginia Polytechnic Insti tute and State University.

Mazar, B. 1989. Excavations in the south of the Tem­pie Mount, Institute of Archaeology, Hebrew University, Jerusa lem.

Moroni, B. & Pol i, G. 1988. Corrosion of Limestone in Humid Air Containing Sulfur and Nitrogen dioxides: a Model Study. Durability of Building Materiais, 5: 367- 373 .

Municipality of Jerusalem 1996. Statistical yearbook of Jerusalem 1994/ 1995. Municipality of Jerusalem and the Jerusalem Institute for Israel studies.

Oh, S.J., Cook, D.C., Townsend, H.E. 1998 Characterization of iron oxides commonly formed as corrosion products on steel. Hyperfine Interactions, 112 (I): 59- 65 .

Peretz, A. 1991. The management and economic aspects of the erection of the Temple Mount. M.Sc. Thesis, Technion - Israel lnstitute ofTechnology, Haifa.

Price, C.A. [996. Stone conservation: an overview of current research, The 1. Paul Getty Trust, Santa Monica, CA, USA.

Rezaie-Serej , S. & Cook, D.c. 1988.Environrnentallnfluence on the formation ofO!-FeOOH on the surface ofweathering steel. Hyperfine Interactions, 41 (l): 70 1- 704.

Sasson, A. 2000. The lime-burning plant at the AIi-Muntar Hill in Gaza. Bulletin of the Anglo-Israel Archeological Society, 18: 83- 103.

SI 6 1999. Terazzo floor tiles (Hebrew). Siddall, R. 2000. Conservation: Material Science. Plaster,

Mortar, Cement & Concrete. Course notes, Department of Geological Science, University College of London, UK. Avai lable from: http ://www.ucl.ac.uk/~ucfbrxs/limes/

G I 23notes.htm [Accessed 10 December 2002]. Sparai, Z., Sason, A. 2001. Stone excavation and quarries

in ancient Israel, Eretz Hefetz Institute "Israel Lights", Education academic college.

Talesnik, M.L., Hatzor, Y.H., Tsesarsky, M. 200 I. The elastic deformability and strength of a high porosity, anisotropic chalk. Int. 1. ofRock Mechanics and Mining Sciences, 38: 543- 545 .

Torraca, G. 1988. Air Pollution and the Conservation of Building Materiais. Durability of Building Materiais, 5: 383- 392 .

252

Tsatskin, A. 1999. The petrography of hydraulic and other building materiais in Caesarea. Caesarea Papers 2, Journal of Roman Archaeology, Suppl. Ser. 35: 419-429. K.G. Holum, A. Raban , and 1. Patrich (eds).

Tsatskin, A., Rohrlich, V, Soroka, 1. , Raban, A. , Berner, A. 2000. Analysis of ancient hydraulic concrete from Cae­sarea by petrographic and material science techniques. Israel Geological Society, Annual Meeting: 95.

Vitruvius, 1931- 34. Di architectura libri decem (English translations by M.M. Morgan, Cambridge, Mass. , 1914, and by F. Granger in the Loeb Classical Library), 2 vols.

Warren, c., Condor, C.R. 1881 . The Survey ofWestern Pales­tine. The Committee of the Palestine Exploration Fund, London.

Wasserman, I. 2003 "Material Characterization of Masonry Stones and Mortar from the Southern Temple Wall in Jerusalem". Proceedings of the 4th Symposium of the Hellenic Society for Archaeometry, Athens (Greece), May 28- June 3 (in press).

253

Wasserman, 1. , Bentur, A. 2004 "Efficiency of Surface Treatment on Enhancement of Durability of Limestone Cladding in the Eastern Mediterranean Offshore Zone". Submitted for the publication in Materiais and Structures, September 2003.

Weisman, G. 1968. Stability of the Southern Temple Wall. Technical Report, Technion - Israel Institute ofTechnol­ogy, Haifa .

Wingate, M. 1985. Small-scale lime burning, a practi­cal introduction, Intermediate Technology Publications, London.

Winkler, E.M. 1997. Stone in Architecture: Proper­ties, Durability. 3rd Edition. Springer-Verlag, Berlin, Heidelberg.

Winkler, E.M. 1982. Problems in the deterioration of Stone. Conservation of Historic Stone Buildings and Monu­ments. Commission on Engineering and Technical Sys­tems, US National Academy on Science, Engineering and Medicine.