Beatriz Menéndez

CY Cergy Paris University

Predicting changes in rocks’ physical and mechanical properties due to weathering progress is among the most challenging scientific topics in engineering geology. This study investigated the role of weathering process in changing the geotechnical characteristics of some samples with different weathering degrees from the Shirkuh batholith (west of Y...

This recommendation is devoted to testing the resistance of natural stone and fired-clay brick units against salt crystallization. The procedure was developed by the RILEM TC 271-ASC to evaluate the durability of porous building materials against salt crystallization through a laboratory method that allows for accelerated testing without compromisi...

Salt crystallization is a major cause of damage in porous building materials. Accelerated salt weathering tests carried out in the laboratory are among the most common methods to assess the durability of material to salt decay. However, existing standards and recommendations for salt weathering tests have limitations in terms of effectiveness and/o...

This work proposes sustainability criteria for the selection or design of restoration mortars based on their physical and mechanical properties, durability, price in the French market, and the environmental impact estimated by the global warming potential. A score is assigned to the mortars based on normalized values of their physical and mechanica...

This paper presents an experimental assessment of the effects of silica (SiO2) nanoparticles on the properties and performance of lime restoration mortars. Mortars were fabricated using calcareous aggregates, and two different types of limes (air, hydraulic) and different amounts of SiO2 nanoparticles. In order to isolate nanoparticles effects on m...

Twelve experimental restoration mortars were formulated using air lime, hydraulic lime or Portland cement as binders. A cradle-to-grave life cycle assessment was used to quantify the potential environmental impacts on the categories of global warming potential, abiotic resources depletion potential-fossil fuels, acidification potential, and the pho...

Three different stone coating products including industrial resin, resin-anatase nanoparticles and resin-rutile nanoparticles (NPs) were used to evaluate their stone surface protection effect against thermal shock and salt crystallization on three types of porous travertine stones. The results showed that the use of nanoparticles of both TiO2 polym...

In the present work, we investigate the mechanical weakening and deformation induced by water on a microporous carbonate rock, the Obourg Chalk from Mons Basin (Belgium), through conventional triaxial tests and injection tests. The injection tests were conducted by waterflooding critically loaded rock samples, initially in dry condition, in a way t...

The RILEM TC ASC-271 is developing a new laboratory test to assess the durability of porous building materials to salt crystallisation. The test encompasses two phases: salt accumulation and damage propagation. This paper focuses on designing a procedure for the accumulation phase; this is considered successful when salts crystallise at the materia...

In order to improve the ecological footprint of the restauration mortars while keeping their efficiency, we have tested several combinations of natural hydraulic lime and air lime with natural aggregates and additives. Repair mortars should be compatible with the support (stones, bricks) and protect original materials from environmental agents; aes...

The work presented here corresponds to some preliminary results of a project whose goal is to study the effects of nanoparticles on the characteristics and performance of lime mortar. As a starting point, a commercial lime mortar was used to produce a set of test specimens to which SiO2 nanoparticles were added in quantities ranging from 1 to 7 wt%...

Persepolis historical complex hosts palaces and tombs which are constructed by stone blocks. These stones suffer from various weathering. Hence, in this study, physico-mechanical properties of Persepolis stone are investigated in relation to some important weathering factors including freezing–thawing, thermal shock and salt crystallization. This s...

Carbonate rocks are well-known to be tremendously heterogeneous. They mainly consist of component particles (from biological and non-biological origin) embedded in a lime-mud matrix and/or in a cement (composed of even smaller particles). The size, shape, density and spatial arrangement of those particles, alongside with natural fractures and crack...

Changes induced by climate change in salt weathering of built cultural heritage are estimated in different ways, but generally as a function of phase changes phenomena of two common salts, sodium chloride and sodium sulfate. We propose to use not only these salts, but also other common salts as calcium sulfate, or mixtures of chlorides, sulfates, a...

The durability of building materials with respect to salt crystallization is commonly determined by accelerated weathering tests, carried out in the laboratory. An effective laboratory weathering test should assess the durability and, in the case of conservation of historic buildings, the compatibility of repair materials with those existing. Besid...

Salts are among the most active weathering agents acting in the degradation of cultural heritage, especially on stone and brick buildings. Most of the previous works on salt weathering studied only single salt composition despite the fact that in buildings a mixture of different salts is always present. This paper presents a methodology to estimate...

The physico-chemical compatibility of the most frequently used commercial stone-repair mortars applied to repair surface damage of a common limestone (Euville stone) employed in the basements of historic buildings from Paris was assessed. The characterization of anhydrous raw mortar materials, of stone and mortar samples collected from these buildi...

The influence of different factors, brine composition, environmental conditions and pore structure, on salt weathering of porous carbonate building stones is investigated. The main goal of this study is to highlight the differences in weathering between single salts and a mixture of different salts. Two kinds of weathering mechanism are studied, th...

The physico-chemical compatibility of the most frequently used commercial stone-repair mortars applied to repair surface damage of a common limestone (Euville stone) employed in the basements of historic buildings from Paris was assessed. The characterization of anhydrous raw mortar materials, of stone and mortar samples collected from these buildi...

An original testing protocol was designed to study the substitution of in situ fluids in reservoir rocks with minimal impact on the in situ effective stress. The weakening effect of the substituting fluid can therefore be easily identified. Our results for the weakly-consolidated Sherwood sandstone show that (i) the strength and static elastic modu...

Non-destructive techniques have always been used in the study of built cultural heritage because of the high cultural value of the concerned objects and the need to preserve them as intact as possible. In this chapter, different non-destructive techniques applied to the conservation of historical building are presented. The selected techniques conc...

Stone-mortar specimens manufactured with limestone and commercial stone-repair hydraulic mortars have been exposed to accelerated ageing tests, salt crystallisation (mixture of sodium chloride, sodium sulphate, calcium sulphate and potassium nitrate) and acid vapours exposure (sulphurous and nitric acid) besides, their corresponding control specime...

The most frequently used restoration mortars used for stone repair of historic buildings from the city of Paris (France) have been selected to study their durability and interaction with one of the most common natural stone used in the basements of these buildings. Three commercial, ready to used, mixtures of natural and hydraulic limes (NHL, HL) m...

Several methods are compared for the detection of moving capillary fronts in spontaneous imbibition experiments where water invades dry porous rocks. These methods are: (i) the continuous monitoring of the mass increase during imbibition, (ii) the imaging of the water front motion using X-ray CT scanning, (iii) the use of ultrasonic measurements al...

To assess water‐weakening effects in reservoir rocks, previous experimental studies have focused on changes in the failure envelopes derived from mechanical tests conducted on rocks fully saturated either with water or with inert fluids. So far, little attention has been paid to the mechanical behavior during fluid injection under conditions simila...

Most buildings of architectural heritage in Paris and its surroundings are built with Lutetian limestone. Several historic buildings of the ‘Vexin Normand’ region show Lutetian limestone in the upper parts of their walls, while the lower parts are built with a chalk known as ‘Pierre de Vernon’. The ‘Pierre de Vernon’ appears up to the first metre,...

Fossil-bearing shale specimens that include sulfides in their compositions are chemically reactive and sometimes also mechanically fragile. This decay is often related to iron sulfate efflorescence resulting from the oxidation of sulfide compounds. The processes underlying these degradations are poorly known, thus impeding the elaboration of curati...

Sodium sulfates are well known to be the most damaging salts in building materials and rocks. Unfortunately, the crystallization processes of sodium sulfates are not completely understood. In addition, the metastable heptahydrate has long been neglected in scientific works on salt damage until recently. In this study, we use temperature monitoring...

Laser scanning confocal microscopy can be used to image the pore structure of geologic materials in three dimensions at a resolution of 200 nanometers. The technique involves impregnation of the void space with an epoxy doped with a fluorochrome whose fluorescent wavelength matches the excitation wavelength. Optical sections with a thickness of les...

4 Vol., ca. 750 p. : ill., fig., tables ; 30 cm .

Sodium sulfate is widely regarded as the most damaging salt for porous building materials. To understand this complex and incompletely understood phenomena, it is important to predict which phases will crystallize under a range of environmental conditions and which phase transitions will cause damage. In this study we present data on the crystalliz...

The banks of the River Seine in Paris are inscribed on the UNESCO List of the World Cultural Heritage since 1991 because they are studded with a succession of masterpieces such as Notre- Dame Cathedral, Sainte Chapelle, Louvre, Place de la Concorde, Tour Eiffel, and with prestigious museums: Louvre, Orsay, Quai Branly, Petit Palais…Unfortunately, t...

Gypsum is one of the most universally distributed salts in weathered materials but little is known about the influence of environmental conditions on the damage generated by gypsum in stones. To quantify the damage induced by gypsum crystallization acoustic emission techniques are employed to record the elastic energy released during salt crystalli...

This work introduces the notion of salt climatology. It shows how climate affects salt thermodynamic and the potential to relate long-term salt damage to climate types. It mainly focuses on specific sites in Western Europe, which include some cities in France and Peninsular Spain. Salt damage was parameterised using the number of dissolution-crysta...

Petrophysical properties were measured on oolitic limestone from the Oolithe Blanche formation (middle Jurassic) in the Paris Basin. Eighteen oriented blocks were collected from three outcrops regarding of the three main facies, oolitic shoal facies, tide dominated facies and prograding oolitic facies. We investigated the relationship between both...

To investigate the effect of compaction bands (CB) on fluid flow, capillary imbibition experiments were performed on Bentheim sandstone specimens (initial porosity ∼22.7%) using an industrial X-ray scanner. We used a three-step procedure combining (1) X-ray imaging of capillary rise in intact Bentheim sandstone, (2) formation of compaction band und...

Imaging fluid flow in porous rocks is a constant challenge in Earth sciences. We present the results of an experimental study to image capillary imbibition processes using an industrial X-ray scanner to investigate fluid motion processes in relation with microstructural properties for various porous rocks. Two-dimensional density maps obtained at a...

La présente étude s'intègre dans le cadre du projet de recherche SHPCO2 (Simulation Haute performance pour le stockage géologique de CO2), financé par l'ANR(1) et en partenariat avec l'IFP, ENSMSE(2), LAGA(3), INRIA(4). Il est dédié au développement d'une plate-forme informatique haute performance pour la simulation numérique du stockage géologique...

We used an industrial scanner to image capillary imbibition processes in order to get some insight into fluid motion processes in several porous rocks. Images obtained at different stages in standard capillary rise experiments on intact and damaged rock samples are analyzed. The geometry of the water front depends on the rock microstructure and its...

The Paris Basin appears to be appropriate in terms of CO2 capture and storage when considering both the amount of CO2 produced and the availability of depleted fields and deep saline aquifers. The purpose of this study is to investigate the petrophysical properties in relation with the sedimento-diagenetic environment of the "Oolithe Blanche" forma...

The aim of this study is to evaluate how the ambient temperature and the salt concentration affect the salt decay of a sedimentary stone. Samples of a detritic limestone have suffered cycles of accelerated ageing at 5, room temperature (around 22 °C) and 50 °C with brines which had different sodium sulphate concentration. The weight of the samples...

In order to get some insight into the influence of mechanical deformation on fluid flow patterns, we performed series of X-ray CT scanning runs during capillary imbibition experiments to image the water front displacement in Bentheim sandstone samples. A three steps procedure was followed: 1) intact rock samples were tested, 2) the samples were def...

The aim of this study is to understand how the porous network of a stone is modified by the crystallization of sodium sulphate. Samples of five different stones have been experimentally weathered and evaluated thanks to mercury porosimetry in three different states: fresh, weathered by salt, and weathered cleaned from the salts. Optical and electro...

We investigated the anisotropic behaviour of the Callovo-Oxfordian argillite in laboratory experiments, and analysed the rock microstructure using different imaging techniques. The starting material was a core retrieved at 460m depth in well EST204 at the site of the French Underground Research Laboratory in the Meuse/Haute-Marne region, from which...

The objective of this study is to understand and predict the alteration of porous rock by crystallization of salts. Samples of different rocks have been tested according to the EN 12370 standard test. Two parameters are proposed to evaluate the alteration of a rock during these tests. The alteration index AI represents the cycle in which the first...

L’importance de l’imbibition capillaire et des processus d’évaporation dans l’altération des pierres de construction sous l’action de la cristallisation des sels solubles est estimée par différents modes opératoires adaptés de la norme européenne EN 12370. Les différents tests consistent à modifier les conditions de l’apport en sel (sulfate de sodi...

The importance of capillary imbibition and evaporation processes in the decay of stone through salt crystallization is estimated by different experiments adapted from the European standard EN 12370. The various tests consist in slightly modifying the salt (sodium sulphate) supply in the porous network of stones as well as the amount of evaporation...

Microstructural analysis of two undeformed sandstones, the Bentheim and Rothbach sandstones, supports the origin of the macroscopic anisotropies previously investigated (ultrasonic P-wave velocity, electrical conductivity and magnetic susceptibility). The shape and spatial distribution of both grains and voids were determined by computer image proc...

This chapter discusses mechanical compaction. In response to an applied stress field or pore pressure changes, the pore space of a rock may compact or dilate. Mechanical compaction induces the porosity to decrease and, as a physical mechanism of diagenesis, it can play an important role, especially during early and intermediate burial. At depths gr...

Due to its sharp resolution ( 100 microns) that can be studied under LSCM. Three different sandstones have been studied: the Rothbach sandstone (Vosges mountains, Eastern France), the Bentheim sandstone (Germany) and the Darley Dale sandstone (UK). On each sample several three dimensional blocks have been investigated with size 228 by 152 microns a...

We have studied four different sandstones under confocal laser scanning microscopy (CLSM). In order to discriminate the void space from the grains, the samples were impregnated with a fluorescent dyed (Rhodamine B) resin and thin-sections with a thickness larger than usual were prepared and studied with CSLM. Two different kinds of samples have bee...

We present an overview of experimental results that we obtained in the last decade on the permeability evolution with stress and the analysis of stress-induced damage in sandstones. The goal of these studies was to get a fundamental knowledge on the interplay between deformation at the microscale level, fluid flow processes and the macroscopic rock...

Confocal scanning laser microscopy (CSLM) is a powerful tool to image the three-dimensional (3D) microstructure of objects in many different fields. The goal of this paper is to show that, in particular, confocal microscopy is a useful tool in geosciences because it provides accurate and relevant information on the 3D geometry of the pore space in...

Confocal Scanning Laser Microscopy (CSLM) was used to characterise 3D crack networks in La Peyratte granite samples in which cracking was artificially induced either by heating samples at selected temperatures in order to induce thermal cracking, or by performing mechanical tests in order to develop stress-induced cracking at room temperature. Our...

New data are presented on the influence of thermal cracking and stress-induced cracking on several physical properties (porosity, acoustic velocity, attenuation, electrical conductivity, permeability) of a fine-grained granite from La Peyratte, France. Two sets of samples were studied: the `TC' set was made of samples in which thermal cracking was...

The purpose of this work was to investigate the influence of cement on the mechanical behaviour of granular rocks. Following the technique described in den Brok et al. [den Brok, S. W. J., David, C. and Bernabé, Y., Preparation of synthetic sandstones with variable cementation for studying the physical properties of granular rocks. C. R. Acad. Sci....

The role played by the petrophysical characteristics of the rock matrix in the radioelement transfer phenomena through the geosphere is considered. The aim of this paper is to correlate information provided by the microcrack network, mineralogy and U-micromapping studies which can be used to quantify the extent of radioelement migration/retention i...

The micromechanics of failure in Berea sandstone were investigated by characterizing quantitatively the evolution of damage under the optical and scanning electron microscopes. Three series of triaxial compression experiments were conducted at the fixed pore pressure of 10 MPa and confining pressures of 20, 50 and 260 MPa, respectively, correspondi...

Laser scanning confocal microscopy can be used to image the pore structure of geologic materials in three dimensions at a resolution of 200 nanometers. The technique involves impregnation of the void space with an epoxy doped with a fluorochrome whose fluorescent wavelength matches the excitation wavelength. Optical sections with a thickness of les...

This paper describes an example of the use of stereological techniques for the quantification of some characteristics of the microcrack network of rocks, in this case the El Berrocal granite. From data measured in sections 2-D, 3-D characteristics of the microcrack network have been obtained. The quantified characteristics are the microcrack densit...

Blocks and cores of El Berrocal granite intersected by hydrogeologically-active fractures have been studied in order to determine (1) the extent to which diffusion of natural radionuclides has taken place from fractures into the rock matrix, and (2) the microstructural controls of diffusion. The results suggest that, in many granitic rocks, matrix...

The pore system of three carbonate rocks is studied through observation of resin and latex casts, under scanning electron microscope. The selected rocks -Hontoria and Seville limestones, and Boñar dolomite- have been broadly employed in the construction of outstanding monuments of the Spanish Historical Heritage. The degree of impregnation achieved...