Grey Tuff Research Articles

Sustainable manufacturing of new construction material from alkali activation of volcanic tuff

The current climate emergency leads to reduction of virgin raw material extraction and promotes circular economy. In this framework, alkali activation of unemployed fraction of grey tuff, combined with glass waste, provides a range of sustainable construction materials. For the sake of sustainability, tuff powder was subjected to rapid attack (30 min), operated by a ‘weak’ alkaline solution (3 M NaOH), and then left to dry at low temperature (75 °C) for 72 h. The addition of Triton X-100 surfactant was considered to obtain foams starting from slurries with different liquid-to-solid ratio. A thermal treatment was applied to selected samples, at low temperature (700 °C). Despite the ‘mild’ activation conditions, all products survived after immersion in boiling water or acid solution, already in the unfired state, according to the formation of a multiphasic gel. The strength-to-density ratio, especially for foams, in both unfired and fired form, compares well with that of already existing construction materials (e.g. it could exceed 5 MPa cm3/g).

Multidrum Stone Columns at the Pompeii Archaeological Site: Analysis of Geometrical Properties and State of Preservation

The seismic vulnerability of ancient free-standing multidrum stone columns is an important issue for the preservation of Greek and Roman archaeological sites. Such elements show a complex and highly non-linear dynamic behavior, requiring specific and sophisticated structural analysis. Different numerical studies on the dynamic behavior of ancient multidrum stone columns found that their seismic response is sensitive to their geometrical parameters, as well as to the material elastic properties, the kinetic coefficient of friction and the amplitude and frequency of the seismic action. Therefore, in the present research, a detailed survey of free-standing multidrum stone columns representative of a wide range of elements at the Pompeii Archaeological site was developed to provide a primary evaluation of the seismic vulnerability of such elements based on their geometrical properties. The study focuses on 103 multidrum grey-tuff columns, from four areas at the site: tetrastyle atrium of Casa del Fauno at Regio VI and Quadriportico dei Teatri, Foro Triangolare and Palestra Sannitica at Regio VIII. Grey tuff was a typically locally sourced natural stone, used as a building material in ancient Pompeii. The research areas included both private (Casa del Fauno) and public buildings (Quadriportico dei Teatri, Foro Triangolare and Palestra Sannitica). The mean overall geometrical properties affecting the seismic behavior of the columns in each research area and the discussion of the collected results are herein presented.

Effect of adding graphene oxide (GO) to Poly (ɛ-caprolactone) (PCL) to induce osteoinductive properties

The lithological analysis of the southern façade of the Sarno Baths, a complex building located in the south-western part of the ancient city of Pompeii (Naples, southern Italy), was addressed to define the types of stone used as blocks and ashlars of the three nearly completely preserved levels. Lithological analysis, coupled with petrographic (optical and electron microscopy) and mineralogical study of the lithotypes macroscopically defined, revealed the use mainly of volcanic and volcano-clastic rocks, and in particular of: (i) yellow tuff supplied from the yellow facies of the Campanian Ignimbrite (about 39 ky BP); (ii) grey tuff from the Campanian Ignimbrite; (iii) leucite phonolitic tephrite from the lava flows of Somma Vesuvius; (iv) travertine from the Sarno limestone (Calcare del Sarno) (Cretaceous). On the basis of the lithological mapping, the basement results mainly composed of leucite phonolitic tephrite, associated to travertine and sporadically to yellow tuff, whereas the other two overhead levels are mainly constituted by tuff and travertine, respectively. In particular, the tuff distribution on the level upon the basement shows a prevalence of grey tuff on the western portion, yellow tuff on the eastern one and in the opus reticulatum band running all along the façade, and marked at the top by a trachyte stringcourse. Travertine blocks in the uppermost façade were probably placed as integration during the restoration works carried out at the end of the 19th century. The distribution on the façade of elements made of different rock types, characterised by different bulk density and mechanical properties, confirms ancient Roman builders’ deep knowledge on the technical features of these materials and their structural behaviour.

Volcanism in The Pre-Semilir Formation at Giriloyo Region; Allegedly as Source of Kebo-Butak Formation in the Western Southern Mountains

Kebo-Butak Formation was known to be the oldest volcanic rocks limited in regional terms in the lower Baturagung Hills, Gedangsari area, Gunungkidul Regency. The main constituents of the Kebo-Butak Formation consist of intersection of volcanic-clastic rocks and calcareous sediments, locally also found basalt lava with pillow structures; which distinguished it from other volcanic rock formations in the Southern Mountains. This study aims to determine the relationship of volcanic rocks exposed in Giriloyo with the Kebo-Butak Formation in the Baturagung Hills; the chronostratigraphy and the history of volcanic activities that produced the volcanic rocks of Giriloyo. This research was approached by volcanic geological mapping using surface mapping suported by gravity anayses. From the bottom to the top of the frontier areas result volcaniclastic rocks consisting of black tuffs with several fragments of volcanic bombs with basalt composition intersecting with thin basaltic lava inserted by calcareous claystone having an age of N5-7 (Early Miocene); pyroxene-rich basalt volcanic sequence consists of thick layers of tuff with creamy-brown color intersecting with lava and breccia inserted by calcareous sandstone aged N7-8; dikes, lava and agglomerates with basaltic composition and lava and agglomerates with andesitic composition. Stratigraphically, the volcanic rocks exposed at Giriloyo correlated with the volcanic rocks exposed at Karangtalun (Wukirsari) were under the Semilir Formation, bordered with normal fault N210oE/77o, the hanging wall composed by light grey tuff of Semilir Formation. Gravity analyses found high anomalies below the Semilir Formation exposed at Karangtalun-Munthuk (east of study area) continued to below the Giriloyo area. The high anomalies were identified as the igneous/ignimbrite volcanic sequence. Descriptively and stratigraphically, the Giriloyo volcanic sequence are a part of Kebo-Butak Formation. The petrogenesis of the volcanic rocks will be discussed in further research to interpret magmatological properties, the evolving paleo-volcano, and the absolute age of the rocks.

Stones of the façade of the Sarno Baths, Pompeii: A mindful construction choice

Abstract The lithological analysis of the southern facade of the Sarno Baths, a complex building located in the south-western part of the ancient city of Pompeii (Naples, southern Italy), was addressed to define the types of stone used as blocks and ashlars of the three nearly completely preserved levels. Lithological analysis, coupled with petrographic (optical and electron microscopy) and mineralogical study of the lithotypes macroscopically defined, revealed the use mainly of volcanic and volcano-clastic rocks, and in particular of: (i) yellow tuff supplied from the yellow facies of the Campanian Ignimbrite (about 39 ky BP); (ii) grey tuff from the Campanian Ignimbrite; (iii) leucite phonolitic tephrite from the lava flows of Somma Vesuvius; (iv) travertine from the Sarno limestone (Calcare del Sarno) (Cretaceous). On the basis of the lithological mapping, the basement results mainly composed of leucite phonolitic tephrite, associated to travertine and sporadically to yellow tuff, whereas the other two overhead levels are mainly constituted by tuff and travertine, respectively. In particular, the tuff distribution on the level upon the basement shows a prevalence of grey tuff on the western portion, yellow tuff on the eastern one and in the opus reticulatum band running all along the facade, and marked at the top by a trachyte stringcourse. Travertine blocks in the uppermost facade were probably placed as integration during the restoration works carried out at the end of the 19th century. The distribution on the facade of elements made of different rock types, characterised by different bulk density and mechanical properties, confirms ancient Roman builders’ deep knowledge on the technical features of these materials and their structural behaviour.

Microwave Treatment of Stone Surfaces for the Devitalization of Biodeteriogens

The experimental work described in this paper is aimed at evaluating the possibility of applying microwave heating to a restoration project. The technique involves the application of microwaves to stone surfaces affected by biodeterioration. Results showed that the pests were completely devitalised. The materials chosen for the survey were yellow and grey tuff. Samples of both tuffs were taken in the area of agro nocerino-sarnese and samples of lime mortar and brick were taken from a ruin located in Saint Eustachio (AV). The methodology consists of two phases: in the first, samples of material are placed in a reverberation chamber and treated by varying the parameters of power and exposure time; in the second, they underwent chemical-physical analysis aimed at establishing whether the treatment had induced aesthetic and/or structural alterations. The procedure was performed both on intact samples and on powdered samples for further analysis. Specifically selected and treated samples were subjected to colorimetric analysis, thermogravimetric analysis, of x-ray diffraction, infrared spectroscopy, SEM, and analysis of transport properties and compressive strength. Results from the chemical and structural analyses relating to the samples treated with the protocol showed no differences between the treated and untreated material. The only difference between the two types of material used related to the absorption capacity of water after treatment. From this, it can be deduced that the heating of stone materials using microwaves devitalizes pests, while leaving the substrate unaltered and the microstructure unaffected by any change.

Games, banquets, handouts, and the population of Pompeii as deduced from a new tomb inscription

A monumental tomb has been discovered at Pompeii in the Stabian Gate area during renovation work on a public building, constructed in the early 19th c., that currently houses the offices of the Archaeological Park. The tomb is part of a necropolis that developed alongside an important gate in the S sector of the city walls. In this area, 19th-c. investigations brought to light the gate as well as a section of paved road and two schola tombs in grey tuff, set directly on the left side of those leaving the city, on public ground and therefore authorised by the ordo decurionum (fig, 1). The first of the tombs is that of Marcus Tullius, a prominent figure in Pompeian society known for the dedication of the Temple of Fortuna Augusta; the second belongs to the duumvir Marcus Alleius Minius. Research was first conducted here by A. Maiuri, then again in the period 2001-2 when an additional stretch of paved road and two tombs on its right side were brought to light. The new, ongoing excavation, launched in 2016 to consolidate the foundations of the 19th-c. building but complicated by that building's looming presence, led to the rediscovery of a monumental tomb which had actually been found, partially excavated and robbed at the moment of the construction of the 19th-c. building.

Preliminary assessment, by means of Radon exhalation rate measurements, of the bio-sustainability of microwave treatment to eliminate biodeteriogens infesting stone walls of monumental historical buildings.

The main purpose of the work described in this paper has been to establish the protocol for a new non-disruptive technique of intervention, based on microwave treatment, for cleaning operations on monumental historical buildings, to eliminate biodeteriogens infesting stones. Non-destructive methods in the cleaning operations, should not only preserve the physical integrity, the chemical-mineralogical and structural identity of materials, but, when the exhalation of pollutant agents (like for example Radon gas) from building materials is considered, also, make the indoor air quality (IAQ) levels healthy. Therefore, one of the main steps of the protocol proposed in this paper is concerned with the assessment of the Radon exhalation rate in order to verify that microwave treatments do not increase the Radon naturally exhalated by building materials. In this paper, the preliminary results of the Radon measurements performed on two different type of tuff samples (grey tuff and yellow tuff), typical of the Italian traditional construction heritage, with the E-PERM passive technique at the Environmental Radioactivity Laboratory (Amb.Ra.), University of Salerno, Italy, ISO 9001:2008 certified, are summarized.

M.E.T.A. - project: a software to retrain the historical buildings

The research offers an easy-to-use instrument (expert system) usable during the stage of the preliminary design, to evaluate the prefeasibility of the operations aimed to the improvement of the energy performances of the building system, compatible with historic and artistic features. The expert system has been processed in collaboration with a partner, a producer of related software and services. The application of this expert system has been conducted on a typical rustic farmhouse, placed in Falciano del Massico and erected with grey tuff in the second half of the nineteenth century.

The ornamental stones of Caserta province: the Campanian Ignimbrite in the medieval architecture of Casertavecchia

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 façades 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.

II.—The Hill of Beath, a Volcanic Neck in Fife

The Hill of Beath, which lies 3 miles to the north-east of Dunfermline, Fife, is an isolated hill with steep, but rounded, contours, and rises fully 250 feet above the surrounding plateau. Whilst the hill itself consists of dark grey tuff, the rocks forming the plateau belong to the Coal-measures of the Carboniferous Limestone series. The latter are thrown into gentle anticlines and synclines, the dip on the limbs of the folds usually lying between 10 and 15 degrees. The outcrop of the tuff has the form of an ellipse, the long axis of which trends east and west and measures nearly 1,000 yards, whilst the breadth of the ellipse is rather more than 500 yards. The distribution of the outcrops of the Carboniferous rocks around the hill and the evidence from the coal workings show that the tuff is not interbedded with the sediments, but that it breaks through them somewhat like an intrusive rock. Sir Archibald Geikie recognized that the Hill of Beath was a volcanic neck, and this view has been confirmed by recent mining operations in a conclusive manner.