Studia Quaternaria, vol. 33, no. 2 (2016): 103–110.

DOI: 10.1515/squa-2016-0010

THE IN FLU ENCE OF NAT U RAL CLI MA TIC FAC TORS ON THE GEOMECHANICAL PROPER TIES OF SILI CEOUS LIMESTONES FROM ()

Joanna Piniñska, Alicja Bobrowska, Dominik £ukasiak Department of Ge ology, Uni ver sity of War saw, ul. ¯wirki and Wigury 93, 02-089 Warsaw, Poland, e-mails: [email protected]; [email protected]; [email protected]

Ab stract Based on the ex ample opoka, stone ar chi tec ture of Kazimierz Dolny, modern re search meth ods were ap plied to an analy sis of geomechanical quali ties of this special rock, selected very effi ciently by medi eval, local builders. Owing to theirs skill and the qual i ties of the cho sen mate rial, for ti fi ca tions, re li gious and res i den tial buildings have been pre - served in good con di tion to the present day. It was ana lysed what fac tors of the opoka ag ing are the most respon si ble for their de struc tion re sistance in the long time scale. The re sults of studies in di cate that opokas have an in creased abil - ity to re duce the uni ax ial com pres sion strength due to the impact of cy cling freez ing and ther mal shock. This ob ser va - tion shows that opokas are char ac ter ized by a high re sistance to humid ity .

Key words: opoka, Kazimierz Dolny, cli ma tic fac tors, geomechanics, de te ri o ra tion.

Manuscri pt re ceived 10 May 2016, accept ed 18 November 2016

IN TRO DUC TION The ori gins of the settl em ent date back to the 11th cen - tury. They were ini tially as so ci ated with the Or der of the The val ley of cen tral is a spe cial area of Po land, Benedictines and after wards the Order of the Norbertines, where a well-known water trade route from southern Europe which gave the set tlem ent the name of Kazimierz, re corded to the Bal tic Sea made a sig nif icant im pact on eco nomic de- for the first time in 1249. The founding of the city and the velop m ent of the region and farther on a unique style of the con struc tion of a for tified cas tle is at trib uted to the Polish Mid dle Ages stone ar chi tec ture. Com mon Up per Cre ta ceous King Kazimierz III the Great. In the first half of the 14th cen - and Neo gene car bon ate rocks from eas ily ac ces si ble, ex - tury, the Polish King Wladyslaw Lokietek founded in the city posed slopes of the river, has had posi ti ve im pact on the buil - a parish church and awarded city rights. A market and streets ding indus try prosper it y. Fol lowing the devel op m ent of the and plots of land for resi den ti al construc tion were de mar- mining of si li ceous limestone rocks opoka: a porous, flinty, cated. Kazimierz Dolny flourishe d in the 16th century , when and cal car e ous sed i men tary rock, con sist ing of fine-grained the grain trade with grain floated by the Vistula to Gdansk de - opaline sil ica (up to 90%), and hardened by the presence of veloped and, after num erous fires, wooden buildings were sil ica of or ganic or i gin (si lici fied res i dues of radiolarian, replac ed with brick archi tec ture. In this period lavishl y dec o - sponge spicules, and di atom s), com monly known as a “white rated grana rie s, town houses and reli gious buildings were stone”, ur ban com plexes were formed with a char acter istic built. In the his tory of medi eval stone building the strongest ar chi tec ture, ex ert ing con sid er able im pact on the cul tural footprint was made by Upper Creta ceous opoka, exploi ted landscape of the region. The evi dence of this influ ence is to di rectly within the area of the city of Kazimierz Dolny, and this day preserve d in medi eval charac ter of the urban layout of th also in nearby Piotrawin, Nasilow, Janowiec or Bochotnica. Kazimierz Dolny and its stone ar chi tecture, changed in16 Sit u ated in vi cin ity, ac ces si ble, easy for treat ment, the rock century from the wooden and infla m mable to brick one allowed for ex tremely var ied dec o ra tion of fa cades with an (Fig. 1). in di vid ual char ac ter prov ing the crafts man ship and high as- De spite the fluc tu a tion of its eco nomic de vel op ment and pira ti ons of the then master s of construc tion ( Fig. 2). war dev as ta tion, Kazimierz Dolny is con tem po rar ily an ur - ban and landsca pe com plex in which the histori c system of a GEOMECHANICAL QUALI TIES OF ROCKS trading gra nary locat ed on the route of the Vistula has been preserve d. This com plex was de clared as a monu m ent of his- Although the knowl edge about the bene fi cia l building tory in 1994 by decree of the Presi dent of the Repub li c of Po- proper ti es of the opoka rocks has deep his tori cal back- land, Lech Walesa. ground, the modern geomechanical studies help estab li sh the 104 J. PINIÑSKA et al.

Fig. 1. Kazimierz Dolny. A – lo ca tion; B – a pre served me di eval ur ban lay out of the old town; C, D – ex amples of me di eval brick build - ings with masonry (in or der: a gra nary, a par ish church). ori gins of the unusual dura bil ity of such a weak, accord ing to strength in the range of 10–30 MPa. It classi fie s them accord - a stan dard clas si fi ca tion of du ra bil ity, con struc tion ma te rial ing to PN-84/B-01080 to the rocks of low and medium dura - (Piniñska and Dziedzic, 2006; Piniñska, 2009, 2010; Marini bil ity. How ever the micrite semiopaque crys tal line matrix of and Bellopede, 2012; Bellopede et al., 2005; Bobrowska, limestone with large amounts of sili ceous sponge spiculas 2013; Piniñska et al., 2014; Bobrowska and Domonik, and residuas of radiolarian, creates a skel etal struc ture, eas ily 2015). Re searches are based on com plex labo ra tory testing observe d in the micro scope im age (Fig. 3B). Thanks to this on the sam ples of opoka rocks from Kazimierz Dolny. gril lage re in forcem ent, the opokas are re sis tant to crack ing Petrographic anal y ses, ul tra sound and phys i cal-me chan i cal and, compar ing to other lo cal car bon ate raw mate ri als of sim- tests were carrie d out togethe r with acous tic emission during ilar den sity, are rel a tively du ra ble (Fig. 3C). Along with sea - the rock frac ture under load. The profil e of dam aged surface soning opokas harden. Their strength increa ses with time. was made by means of the roughness test with usage of This advan ta geous feature of opoka was known and used in HommelWerke Profilometer. In the mechan ical tests the the Middle Ages. Labo ra tory testing of W.C. Kowalski method ol ogy recom mended by the ISRM (1988) was ap - (1961), W.C. Kowalski and £oziñska-Stêpieñ (1965) show plied and the behav iour of the rocks in pre-criti cal and post- that after several months of season ing the strength of opoka criti cal states of dam age against the background of acous tic increa ses more than 60% (Fig. 3D). emission (AE) was analy sed. The si li ceous limestone (opoka) At the same time their high po ros ity creates their ex cel- rocks which show the nat ural block fragm enta ti on in the lent insu la ti on and lightweigh t makes their shaping easy. The quarry (Fig. 3A ) belong to the very light and light rocks (rs of proces s of strengthen ing of rock caused by sili ceous rein - 1.4g/cm3 to 1.6g/cm3), are highly porous (n ~ 40%) with the forcem ent of struc ture is confirm ed by studies of the defor - GEOMECHANICAL PROP ER TIES OF SI LI CEOUS LIME STONES 105

Fig. 2. A, B, C – Orna mental fa cades of Przybyla broth ers’ town houses at St. Chris to pher Street (ca.1615 ); D – church of St. John the Bap tist (1586–1589). mati on path (Fig. 4A) and paral lel acous tic emission path THE SUS CEP TI BIL ITY OF OPOKAS (Fig. 4B) while loading. As can be seen from the test graphs TO DE FOR MA TION at the pre-criti cal state of de for mation only a few signs of brit tle destruc tion can be observe d and the same is recorded The re sults of obser va ti on of the opokas in the histori c by a very poor pre-criti cal acous tic emission ac tiv ity. buildings of Kazimierz Dolny lead to the conclu sion, that the In the post-crit ical state, af ter the de struc tion path passes most com mon mech a nisms of de te ri o ra tion of their stone the pick point (Rc), opokas still re tain a sig nif icant re sid ual walls due to the aging proces ses are: change of wall tint, loss strength (Rcrez) of up to 50% Rc. This is connect ed with the of wall bricks and their mortar (Fig. 6). ap pear ance of mul tiple small micro- cracks that are read able The dam ages of the opoka walls of the monu m ents are on both defor m ati on and acousti c emission curves. They may re lated to the pen e tra tion of cor ro sive wa ter so lu tions into the becom e paths for water into the porous structure . On the cracked blocks and the inva sion of micro or gan ism s, both other hand, the test re sults of the roughness shown by the changing the col our of the stone and causing crushing and HommelWerke Ba sic Map, prove that the cracks have a high loss of mortar during the seasonal cli mati c changes. Lack of surface roughness. Thanks to this opokas still keep the resid - proper drainage and loca ti on near the steep slopes causes in - ual strength despit e of their signif i cant defor m ati on (Fig. 5). sta bil ity of their founda ti on and cracking of stone walls. Ad - 106 J. PINIÑSKA et al.

Fig. 3. The ad van ta geous prop er ties of opokas. A – block frag menta tion; B – the micrite structure rein forced by the grillage of silica sponges spicula; C – a low den sity (rs) rock with a rel a tively high compres sion strength (Rc); D – a rock be coming harder (in crease of Rc) due to sea soning (Kowalski, 1961). GEOMECHANICAL PROP ER TIES OF SI LI CEOUS LIME STONES 107

Fig. 4. Pre-crit i cal and post-crit i cal paths of de for ma tion of opokas: A – the de for mation curve; B – the acous tic emis sion curve. di tion ally, the his toric build ings of Kazimierz Dolny are opokas proper ti es were ana lysed by model li ng the inter ac- often poorly maintai ned by usage of mortar s not proper to the tions be tween the nat u ral en vi ron ment and opoka be hav iour opoka fea tures. The walls preserve d by cover of plaster lose at labo ra tory . As a main im pact aging factor in the envi ron - their re gional char ac ter so im por tant for me di eval her i tage. mental condi ti ons of Kazimierz Dolny was chosen a vari able Due to the observe d dam aging of the his tori cal walls, the con ti nen tal cli mate, with high rain pre vail ing at sum mer time 108 J. PINIÑSKA et al.

Fig. 5. Roughness surfaces of the cracks in opoka: A – di a gram 2D of the crack; B – di a gram 3D of the crack; C – rough ness profile (Piniñska and Dziedzic, 2006; 2007).

Fig. 6. Humid and discol oured parts of a walls: A – the cas tle stone walls, B – displace ment of the walls on the steep slopes, C – opokas walls of a former granary cov ered with plaster.

(aver age annual rainfal l 550 mm) with a signif i cant sum mer the de te ri o ra tion in dex of in teg rity (I) was es tab lished, char- in so la tion of white walls (at temper a tures up to 50°C) at an acter ized by a re duc tion of the ini tial com pres sive strength aver age tem pera ture of –5.0–18.7°C (Woœ, 1999). (Rc) of rocks due to the influ ence of a given destruc tive fac - The 20 sam ples of opoka were subject ed to cycli c testing tor. It was ex pressed by the re la tion of the initial value (Rc) to of freez ing and thawing re sis tance (PN-EN 12371 ), therm al the value after the model li ng (Rcx). Stud ies in di cate that shock re sis tance (PN-EN 14066), de te ri o ra tion of wa ter ab- opokas strength under the influ ence of the hum idit y decrea se sorpti on (PN-EN 13755) and the com pression strength tests by nearly 10% and due to the impact of cy clic freez ing and (PN-EN 1926) at initial state and af ter model tests. This way, thaw ing and therm al shock resis tance of about 29% (Ta ble 1). GEOMECHANICAL PROP ER TIES OF SI LI CEOUS LIME STONES 109

Fig. 7. A – Frag ments of a modern ho tel in Kazimierz Dolny; B – a re newed syn a gogue; C – a styl ish retain ing wall protected from rain and moisture.

Ta ble 1 sea soning opoka after extra cti on from the quarry and its pro- Av er age val ues of uni ax ial com pres sion strength (Rc) and tec tion from hum idit y in masonry struc tures. In the varied index of integ rit y (I) of opokas of Kazimierz Dolny in morphol ogy of Kazimierz Dolny a proper posi ti oning and mod elled con di tions use of re in forcem ents and re tain ing walls, in accor dance to the medi eval art, is of a vital im portanc e. Thus construc tors Uni ax ial com pres sive In dex In teg rity Test con di tion should re mem ber that cracking and loss of brick mortar is re - strength [MPa] I=Rcx/Rc[-] sult of the movem ent of the subgrade over the steep slopes ini tial state Rc 26.0 and causes the circu la ti on of corro sive solu ti ons through the freezing and thawing (Rcm) 18.4 0.50 rock. Conse quentl y the rock with destruc ted struc ture be- ther mal shock (Rcst) 18.0 0.48 comes more sensi ti ve to cli mati c corro sion and anthropic wa ter ab sorp tion (Rcn) 23.2 0.80 pres sure.

These stud ies shows that opokas are char acter ized by a high REF ER ENCES re sis tance to hu mid ity. Bellopede, R., De Regibus, C., Manfredotti, L., Marini, P. 2005. Wa ter Ab sorp tion and ul tra sound pulse ve loc ity to eval u ate the SUM MARY de cay of stones, in Non De struc tive In ves ti ga tions and Mi- The re sults of contem porary geomechanical studies fully croanalysis for the Di ag nostics and Con ser va tion of the Cul - tural and En vi ron men tal Her i tage, 15–19, Maggio Lecce confirm the specif ic proper ti es of opoka and explai n their Bobrowska, A. 2013. Changes in the strength of salt crystal li za tion wide spread use in the medi eval lo cal stone ar chi tecture and con di tions and the ef fect of sul phur di oxide on some macro- de vel op ment of me di eval build ing in dus try. Bas ing on the po rous car bonate rocks. Przegl¹d Geologiczny, Vol. 61, No. 5, th opokas min ing the mon u men tal, 16 cen tury stone ar chi tec- 311–314 (in Pol ish with Eng lish summary ). ture of Kazimierz Dolny raised thanks to the knowl edge and Bobrowska, A., Domonik, A. 2015. Ul tra sonic waves and strength skill of master s of construc tions of that time, and current ly re duc tion in dexes for the as sessment of the ad vance ment of de - occu pies an im portant place in the cul tural her itage of the te ri o ra tion pro cesses in travertines from Pamukkale and Hie- south-east ern Poland. However the result s of the geome- rapolis (Turkey). Studia Geotechnica et Mechanica, Vol. 37, chanical resea rches show that opokas, without proper con- No.3, 3–9. ser va tion are sen sitive for cyclic clim ate changes and ag ing ICOMOS, 2010. In ter na tional Sci en tific Com mit tee for Stone (ISCS), Il lus trated glos sary on stone de te ri o ra tion pat terns. and the subgrade of the founda ti on of struc ture needs to be ISRM, 1988. Suggested Meth ods for Determinig the Frac ture Tou- well drained. ghness of Rock. Commis sion on Test ing Meth ods. In modern time the new technol o gies and the devel op - Kowalski, W.C. 1961. The com pres sive strength Senonian con - ment of global dis tri bu tion of dec o ra tive stones su per seded struc tion rocks in the rearch area of the Mid dle Vistula river on the medi eval preva lenc e of opokas in the regional construc - the back ground of their li thol ogy. (Wytrzyma³oœæ na œciskanie tion indus try . However, the form er splendour of Kazimierz budowlanych ska³ senoñskich prze³omowego odcinka Wis³y Dolny is be ing re stored in a modern form. In old medi eval œrodkowej na tle ich litologii), Biul. Geol., Wydz. Geol. UW., grana rie s, hotel s are being set up, the recon struc tion of the Vol. 1, Part 2. Warszawa (in Pol ish with Eng lish summary ). forti fied cas tle with the use opoka wall is quickly progress - Kowalski, W.C., £oziñska-Stêpieñ, H., 1965. Li thol ogy of the Up - per Cre ta ceous rocks of the Mid dle Vistula river val ley and the ing, and in local , stylish buildings, outskirt s of the old town ad ja cent up lands. Mat. Sympozjum w Kazimierzu Dolnym, the opoka starts to dom inate (Fig. 7). NOT. Katowice, 805–819 (in Pol ish with Eng lish summary ). This trend supports the tradi ti on and dec ora ti ve val ues of Marini, P., Bellopede, R. 2012. Sand stone de cay: from histor i cal “white stone”. It empha sizes the lo cal na ture of the avail abil - build ings to lab o ra tory tests, Struc tural anal y sis of his tor i cal ity of the mate rial and ex poses its spe cial prop er ties. It is cru - con struc tions, 691–696. cial to rem em ber, however, that the use of rocks require s the Piniñska, J., Domonik, A., Dziedzic, A., £ukasiak, D. 2014. The 110 J. PINIÑSKA et al.

meth od ol ogy of a com plex en gi neer ing-geo log i cal ap proach 725–732. to es tab lish a geopark: Case study of the Ma³opolska Wis³a Piniñska, J. 2010. Rock mining in dustry in the re gion. De - River Gorge. Geo log i cal Quar terly, 59 (2), 408–418. struc tion or De vel op ment. Prace i Studia Geograficzne. Vol. Piniñska, J., Dziedzic, A., 2006. The strength and de for mation 44, Warszawa, 153–167 (in Polish with Eng lish summary ). prop er ties of rocks. Part V Lublin re gion. Cat a logue. (W³aœci- PN-EN 12371. Nat u ral stone test methods – Deter mina tion of frost woœci wytrzyma³oœciowe i odkszta³ceniowe ska³. Cz.V. Re - re sis tance; gion lubelski. Katalog), Vol.9, Warszawa (in Pol ish). PN-EN 13755. Nat ural stone test methods – Deter mina tion of wa - Piniñska, J., Dziedzic, A., 2007. Re sistance and de for mation rock ter ab sorp tion at at mo spheric pres sure; prop er ties. Part V Lublin re gion. De scrip tions and in ter pre ta - PN-EN 14066. Nat u ral stone test methods – Deter mina tion of tion. (W³aœciwoœci wytrzyma³oœciowe i odkszta³ceniowe ska³. ther mal shock re sis tance; Cz.V. Re gion lubelski. Objaœnienia i interpretacja), Vol.10, PN-EN 1926. Nat u ral stone test methods – Deter mina tion of com - Warszawa (in Polish). pres sive strength; Piniñska, J. 2008. The Lublin Si li ceous Car bonate Rocks – a Me - PN-84/B-01080. Kamieñ dla Budownictwa i drogownictwa. Po- dieval Building Mate rial, its Geolog i cal Setting, Specific dzia³ i zastosowanie wg w³aœciwoœci fizyczno-mechanicz- Prop er ties and De te ri o ra tion Pro cesses. 11th In ter na tional nych. PKN i M. Warszawa. Congress on Dete ri ora tion and Con ser va tion of Stone. Vol. Woœ, A., 1999. The Cli mate of Po land (Klimat Polski), PWN (in 1. Nicolaus Co per ni cus Uni ver sity press. Toruñ. Po land, Pol ish).