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This paper reports a detailed study on some relevant portions of the main façades of Caserta Royal Palace (Reggia di Caserta), one of the most important Italian monuments, comparable for its impressive architecture to the Royal Palace of Versailles in France and considered the largest royal palace in the world by volume. The research was focused on the weathering pathologies affecting the stone surfaces that, in the last decades, suffered several detachments of fragments from the coatings and from other architectural elements such as string courses, eaves, and capitals. A preliminary characterization of the materials of the façades and an evaluation of the relative weathering pathologies provided the information required for appropriate restoration and securing of these portions of the building. In particular, an innovative evaluation procedure which draws on techniques typical of the earth sciences allowed the proposal of a ‘risk attitude’ applied to discrete portions of the geomaterials used in the built heritage which is based on the influence of different factors leading to weakening of the stone and to the final detachment of rock fragments. Such a large and complete set of information should be carefully considered by the project planners to adopt the required steps for a suitable risk mitigation and for securing the site during restoration.

In this work, four zeolite-bearing materials (three naturally occurring and one of synthetic origin) were considered for thermal energy capture and storage. Such materials can store thermal energy as heat of desorption of the water present therein, heat that is given back when water vapor is allowed to be re-adsorbed by zeolites. This study was carried out by determining the loss of water after different activation thermal treatments, the water adsorption kinetics and isotherm after an activation step of the zeolites, the intergranular and intragranular porosity, and the thermal conductivity of the zeolite-bearing materials. Moreover, the thermal stability of the framework of the zeolites of the four materials tested was investigated over a large number of thermal cycles. The results indicate that zeolite 13X was the most suitable material for thermal energy storage and suggest its use in the capture and storage of thermal energy that derives from thermal energy waste.

Six zeolite-bearing rocks, often used as building materials, were analyzed by thermodilatometry, together with a rock not bearing zeolites and a plaster covering a containing wall made of zeolite-bearing dimension stones, up to 250 °C. The main results obtained were the following: (i) the zeolite-bearing rocks exhibited very small, if any, positive variation of ΔL/Lo (%) up to about 100 °C, whereas they more or less shrank in the temperature range 100–250 °C (final values ranging from −0.21 to −0.92%), (ii) the rock not bearing zeolites regularly expanded through the whole temperature range, attaining a final value of 0.19%, (iii) the plaster showed a thermodilatometric behavior strongly affected by its water content. Obtained results were interpreted based on plain thermal expansion, shrinkage by dehydration, cation migration and thermal collapse of the zeolitic structure. The decay of the zeolite-bearing building materials was essentially related to: (i) the large differences recorded in the thermodilatometric behavior of the various rocks and the plaster, (ii) the different minerogenetic processes that resulted in the deposition of the various zeolite-bearing rocks.

Two zeolite-rich rock samples extracted from Campanian Ignimbrite tuff quarries, southern Italy, usually used as binding and anticaking agents in animal feeding, were characterized and tested in terms of their resistance in stomach, small and large intestine of pig, using a three step in vitro digestibility trial. The mineralogical composition and major and trace-elements analysis were performed after each digestion step using XRPD and ICP-OES techniques. The main zeolite phases identified are phillipsite and chabazite. Results showed that in vitro physical-chemical conditions (pH 2–3 and T 39 °C) the release of Pb and other elements from the zeolite structure is extremely low and due to the limited breakdown of the zeolite framework and glass/amorphous matter hydrolysis, by the gastric liquids. This aspect also suggests that zeolites, after the total permanence in the animal body digestive tract, can further perform their important function of cation exchanger, with also relevant relapses on the growth and health of the animal species, as well as on the environment. Moreover, the contact of zeolite material with liquids of small and large intestine leads to negligible release of undesirable elements, which are far less than those envisaged by the European Regulations.

Low-cost, naturally-occurring mixtures of feldspar and zeolite occurring in epiclastic rocks are promising substitutes for conventional quartz-feldspathic fluxes in ceramic bodies, since their fusibility and low hardness are expected to improve both grinding and sintering. Three epiclastic outcrops, with a different zeolite-to-feldspar ratio, were characterized (XRPD, fusibility) and tested in porcelain stoneware bodies; their behaviour during processing was appraised and compared with that of a reference. The addition of an epiclastic rock (20 wt.%), replacing rhyolite and aplite fluxes, brought about some significant advantages, mainly represented by better grindability, lower firing temperature with improved mechanical strength and lower porosity. Disadvantages concern increased slip viscosity, worse powder compressibility, resulting in larger firing shrinkage, and a darker colour of the tiles due to relatively high amounts of iron oxide.

This paper reports novel data concerning the volcanic formation of the Piperno, a stone that has been used for a long time in the monumental architecture of Naples and the Campanian region (Southern Italy). A careful field survey of the outcrops or underground sites so far accessible allowed us to draw a lithostratigraphic reconstruction of the formation and enabled the recognition of the three main layers exploited in past centuries and which provided dimension stones for architectural and structural purposes. Petrophysical and mineralogical characterization also enabled us to discriminate the same layers previously identified. Different scoriae/matrix ratio, scoriae dimension and welding degree are the most peculiar features of these horizons. The combination of these three parameters, even though they did not affect the use of Piperno as dimension stone, somehow determined its variable susceptibility to the weathering agents. However, a linear relationship between the exposure time and the decay of the stone itself, at a parity of weathering intensity, was not observed. This assumption was proved by verifying that the specific layers of the volcanic sequence controlled the weathering degree of Piperno from monuments disregarding their age of emplacement.

Zeolite-rich volcanic tuffs are widely distributed in almost every country of the world, where they are present in low-, medium-, or high-grade million-ton deposits. Even though the formation of the zeolite minerals may have followed different genetic paths, the zeolitic rocks have in common a matrix of finely crystalline zeolite that cements the other nonzeolitic particles and is responsible for the overall mechanical properties of the material. Zeolitic tuffs have been employed since pre-historic times in construction, mostly as dimension stone. This use is still the most common of natural zeolites in the building industry, although other applications have recently come to the forefront, such as lightweight aggregate or as additives for manufacturing blended cements. Given the fact that much of this material is excavated and used locally and that the market demand is strongly affected by the trends of the building industry, estimates of the worldwide zeolitic tuff production for construction purposes are difficult to make. In Italy, where the use of zeolitic tuff as dimension stone is commonplace, about 75 quarries were reported in operation in 1992 with total production of about 3 x 106 tons per year (Aiello 1995). More recently, this production has decreased, due to the crisis of the building industry, and in 1998 it amounted to about 1.5 × 106 tons per year. In Japan, the production of tuff as dimension stone is currently about 4 × 105 tons per year (N. Kuchitsu, National Research Institute of Cultural Properties, Tokyo, Japan, pers. comm., 1996). Considering that zeolitic tuff is used as dimension stone in many other countries as well, e.g. Bulgaria, Cuba, Germany, Greece, Hungary, Mexico, Romania, and Turkey, the current worldwide zeolitic tuff consumption as dimension stone is about 3 × 106 tons per year. Information is even more …

Three Italian zeolitized volcanoclastic deposits with predominant phillipsite, chabazite or clinoptilolite were selected to investigate their attitude to form ceramized products of the Cs- and Sr-enriched forms and to evaluate the effectiveness of immobilization by means of leaching tests. The mineralogical evolution was carefully followed after thermal treatments at increasing temperatures (800 °C up to 1100 °C) which led to the crystallization of prevailing pollucite for Cs-exchanged phillipsite and chabazite and of a Sr-feldspar (about 35 wt.%) along with cristobalite and amorphous matter for all Sr-exchanged zeolites. Cs-enriched clinoptilolite at the same temperature was almost totally amorphous. Leaching tests confirm the substantial immobilization of the polluting cations in the ceramized materials with slight higher values only for the Cs-enriched clinoptilolite, mostly amorphous. Finally, calorimetric tests account for a hydrolysis process widely decreasing after thermal treatments at 1100 °C for phillipsite and chabazite, both Cs- and Sr-enriched, substantially similar for Sr-enriched clinoptilolite and definitely increased in the prevailing amorphous Cs-enriched clinoptilolite. © 2011 Elsevier B.V. All rights reserved.

Bryozoan and Lithothamnion limestones (BLL) from central- southern Italy, commercially known as Perlato Royal Coreno, were used for a long time in the monumental architecture of the Campa- nia and Lazio regions. In this paper, new mineralogical-petrographical and engineering- geological data about BLL are reported and the relations between the lithofacial and technical features of this stone are investigated. A field survey of the main limestone outcrops allowed a lithostrati- graphic reconstruction of this formation to be drawn and the eight main lithotypes presently used as dimension stones to be recognized. Mineralogical and petrographical characterization was performed by means of X-ray powder diffraction and optical microscopy observa- tion of thin sections (under transmitted, UV-reflected light and cold cathodoluminescence). Petrophysical characterization enabled to com- pare some engineering-geological properties and to evaluate the influ- ences of rock fabric, chemical composition, fractures and stylolithes on the technical features of the stone. Ageing tests were also performed. Finally the main weathering phenomena affecting the stone were recognised through a detailed study on the facades of the bell tower of the Santa Chiara monastery in Naples.

The crystal structure, crystal chemistry, and low-temperature structural evolution of natural thomsonite from Terzigno, Somma-Vesuvius volcanic complex, Naples Province, Italy, have been investigated by means of in situ single-crystal X-ray diffraction, electron microprobe analysis in the wavelength dispersive mode, and Raman spectroscopy. Six structure refinements have been obtained at different temperatures: 295.5, 248.0, 198.0, 148.0, 98.0, and 296.0 K (after the low- T experiments). The reflection conditions and the structure refinements prove that the crystal of thomsonite here investigated is orthorhombic with a = 13.0809(3), b = 13.0597(3), c = 6.6051(1) A, V = 1128.37(14) A 3 , and space group Pbmn , which differs from thomsonite from different localities reported in previous studies (with a ~ 13.1, b ~ 13.06, c ~ 13.2 A, and space group Pncn ). The refined bond distances suggest that the Si/Al-distribution in the tetrahedral framework is fully “disordered,” giving rise to the halving of the c axis relative to that found in “ordered” thomsonites. The extra-framework population consists of: (1) one site about 50% occupied by Ca (labeled as “Ca”); (2) one site occupied by Na (~70%) and Ca (~30%) (labeled as “Na”); and (3) three water molecule sites (“W1,” “W2,” “W3”). The structure refinements allowed the location of all the proton sites, and the hydrogen-bonding scheme in the structure is provided. The low-temperature refinements show no significant change in the structure within the T -range investigated. The evolution of the unit-cell volume with T exhibits a continuous and linear trend, without any evident thermo-elastic anomaly, with thermal expansion coefficients α V = V −1 ·∂ V /∂ T = 20(2)·10 −6 K −1 (between 98.0 and 295.5 K). A list with the principal Raman active modes is provided and a comparison with the vibrational modes previously found for “ordered” thomsonite is carried out.

This research provides possible opportunities in the reuse of waste and particularly muds, coming from both ornamental stone (granite sludges from sawing and polishing operations) and ceramic production (porcelain stoneware tile polishing sludge), for the manufacture of lightweight aggregates. Lab simulation of the manufacturing cycle was performed by pelletizing and firing the waste mixes in a rotative furnace up to 1300 degrees C, and determining composition and physicomechanical properties of lightweight aggregates. The best formulation was used to produce and test lightweight structural concretes according to standard procedures. Both granite and porcelain stoneware polishing sludges exhibit a suitable firing behavior due to the occurrence of SiC (an abrasive component) which, by decomposing at high temperature with gas release, acts as a bloating promoter, resulting in aggregates with particle density1 Mg/m3. However, slight variations of mixture composition produce aggregates with rather different properties, going from values close to those of typical commercial expanded clays (particle density 0.68 Mg/m3; strength of particle 1.2 MPa) to products with high mechanical features (particle density 1.25 Mg/m3; strength of particle 6.9 MPa). The best formulation (50 wt.% porcelain stoneware polishing sludge +50 wt.% granite sawing sludge) was used to successfully manufacture lightweight structural concretes with suitable properties (compressive strength 28 days20 MPa, bulk density 1.4-2.0 Mg/m3).

Results of a research carried out on the lavas from Campi Flegrei and Somma-Vesuvius volcanic districts are reported here. The lavas have been widely employed, since Roman age, in several important monumental buildings of the Campania region, mainly in the town of Naples and in its province. They are classified as trachytes (Campi Flegrei products), tephri-phonolites and phono-tephrites (Somma-Vesuvius complex) from a petrographical point of view. Sampling was carried out from well-known exploitation districts. A substantial chemical difference between the products of the two sectors was confirmed, while petrophysical characterization evidenced similarity among the two different materials, although some differences were recorded even in samples coming from the same exploitation site.

A detailed mineralogical and petro-physical characterization was carried out on Campanian Ignimbrite (CI) formation, a volcaniclastic rock widespread over the Campania region. This stone represented and still is an important building material since historical times. Given the huge extension of this formation (about 30 000 km 2 ) the attention was mainly focused on the historical exploitation areas that provided building materials for the medieval village of Casertavecchia. Building stones (different facies of CI) used facciavista in some relevant monuments of this village were also characterized to carry out a comparison with the in situ corresponding rock. At the same time a complete survey of all the lithotypes used for the facades of the village as well as their state of conservation and weathering phenomena was also performed. As expected, CI in its different facies resulted the most common building stone, also affected by severe weathering such as lacks, alveolization and biological patinae, decay forms likely related to the high textural heterogeneity of the rock. Mineralogical and petro-physical characterization allowed to distinguish, within the investigated outcrop area, three different facies: dark, light and earthy grey tuff (DGT, LGT and EGT, respectively). Differences in mineralogical data mainly consist in the presence of clay minerals in the EGT facies only. K-feldspar always occurs in very high amounts (80–90%). As far as geomechanical parameters are concerned, the most pronounced differences are recorded in water absorption capacity, ultrasonic velocities and UCS values. These tests evidenced a substantial homogeneity of DGT and LGT facies and an overall worse behavior of EGT. Tests performed on CI samples from both monuments and outcrops gave similar results. This evidence strengthened the former hypothesis of a location of CI historical quarrying sites close to Casertavecchia. The only exception is the tuff used for the Mastio of the castle, whose chemical features are definitely referable to a different volcaniclastic formation. © 2004 Elsevier SAS. All rights reserved.

Low-cost zeolitic rocks are promising substitutes for feldspathic fluxes in ceramic bodies, since their fusibility, modest hardness and high cation exchange capacity (CEC) should improve grinding and sintering. Five large-scale Italian deposits of natural zeolites with different mineralogy were characterised and tested in porcelain stoneware bodies. Their behaviour during processing was appraised and compared with that of zeolite-free bodies. Zeolites increased the slip viscosity during wet grinding, causing a coarser grain size distribution and consequently some drawbacks in both unfired and fired tiles. After overcoming this hindrance by dry grinding of zeolite rocks, the technological behaviour of zeolite-bearing tiles appear to be similar to that of current porcelain stoneware, though with larger firing shrinkage and residual closed porosity.

The aim of this research is to assess the possible use of Italian zeolitic rocks for the production of lightweight aggregates. In particular, both the expansion at high temperature and the technological features of fired products were investigated. Fifteen zeolite-bearing volcanoclastites from Northern Sardinia and three zeolitized tuffs from Campania and Tuscany (Sorano and Campanian ignimbrites and Neapolitan Yellow Tuff) were taken into account. The firing expansion turned out to be mainly dependent on the chemical composition (especially SiO 2 and fluxing oxides such as Fe 2 O 3 , Na 2 O, K 2 O, MgO and CaO) and the water content (largely related to the zeolite amount) of the raw materials. Other relevant parameters were the temperature of maximum expansion (ranging between 1350 and 1500 °C, without additives) and soaking time (between 2 and 5 min). Some products are highly impervious to water (water absorption below 1%) and exhibit a considerable firing expansion (>100% in volume), a low bulk density (0.5–0.7 g·cm −3 ) and fair technical properties (loose weight and strength of particles). These encouraging results make some of the investigated tuffs interesting raw materials for the production of lightweight aggregates.

Publisher Summary In Campania region (Southern Italy), the large availability of volcanic products determined the utilization of these products for structural purposes. Neapolitan Yellow Tuff (NYT), Campanian Ignimbrite (CI), and Piperno (PI) were the most widely used volcanic products in historical architecture of Campania region.. This chapter describes the mineralogical and petrographical features of these materials and the research conducted to study the decay phenomena by means of laboratory simulations, which reproduce the aging processes of the stone. Mineralogical characterization was carried out by scanning electron microscopy (SEM) observations and by X-ray powder diffraction analysis (XRPD). Open porosity was calculated by He-pycnometer. Water absorption was measured by immersion test. Ageing tests, wet-dry and salt crystallization tests, were performed to study the decay phenomena. From the mineralogical analysis, a substantial difference was found out between the NYT on one side, and CI and PI on the other. The matrix of the former is mainly constituted by zeolites, amorphous phases, and volcanic glass; and the latter (CI and PI) have a matrix constituted by feldspars and minor amount of glass. The chapter provides table to illustrate variation of the physico-mechanical properties (porosity, water absorption, and uniaxial compressive strength) after aging tests. The overall results obtained show poorer durability of Neapolitan Yellow Tuff, when compared to other stones.

Experiments on zeolitization were conducted on four synthetic monocationic glasses (Na, K, Ca, or Mg-rich glass) with Si/Al molar ratios of 2.67, similar in acidity to many volcanic glasses of partially zeolitized Italian tuffs. The products of the hydrothermal treatment at 100, 150, and 200°C of single glasses or glass mixtures with deionized H2O or monosaline solutions (NaCl, KCl, CaCl2) were characterized by X-ray diffraction, thermal, microscopic and chemical analyses. Chemical analyses of mother liquors were also performed. Mineral assemblages, containing chabazite, phillipsite, analcime, and K-feldspar, very similar to those found in altered, volcaniclastic alkali-trachytic or trachytic glass deposits were produced. Potassium was essential to chabazite and phillipsite crystallization, although phillipsite was obtained also in Ca-Na mixed systems. Sodium was necessary for analcime formation. Calcium plays only a secondary role in zeolitization, and magnesium does not favor zeolite crystallization but promotes the formation of smectite. Glass composition determines the mineral assemblages obtained and hence in those commonly found in nature.

A method, based on water vapour desorption, for the estimation of zeolite content in mixtures of hydrated phases is presented. The accuracy and reliability of the method and the ease of its application are demonstrated through an evaluation of the chabazite and phillipsite contents of Italian tuffs. The method is suitable for more general use provided that the pure phases of the mixture under investigation are available and their thermal features are known.

The survey of materials constituting the buildings of the ancient city centre of Naples and of their decay typologies was carried out. Reports were entered in a database which enabled us to draw two thematic maps in a digital format: one of materials and lithotypes, and one showing weathering. On this basis, quantitative evaluations of the lithotypes were carried out. The research pointed out that the use of different lithotypes was mainly as a result of their availability and/or ease of exploitation. Furthermore, the importance of the preservation of the quarrying sites was stressed, both for their historical and cultural interest and, above all, for possible forthcoming provisioning finalized to restorations. The analysis of the results, made on a geo-mineralogical basis, as well as the thematic maps, gives a basic tool which will be very useful to those professionals involved in preservation of cultural heritage.