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A favorable environment for fungi colonization in building materials' surfaces can emerge when certain hygrothermal conditions occur. Thus, reducing fungal growth susceptibility is of major interest. Furthermore, if the integration of bio-wastes is performed in parallel with the development of innovative materials for this purpose, a more sustainable and environmentally friendly material can be obtained. In this study, the fungal susceptibility of lime mortars incorporating almond-shell powder (ASP) microparticles (2 and 4%, wt.–wt. in relation to the binder content) was evaluated. The particle-dispersion technique was employed to prepare the bio-waste introduced in the mixtures. The fungal susceptibility of ASP samples was compared with nanotitania (n-TiO2) with recognized antifungal properties. Mechanical strength, water absorption, and wettability tests were also performed for a better characterization of the composites. Although the addition of 2% ASP led to mechanical properties reduction, an increase in the compressive and flexural strength resulted for 4% of the ASP content. Difficulties in fungal growth were observed for the samples incorporating ASP. No fungal development was detected in the mortar with 2% of ASP, which may be correlated with an increase in the surface hydrophobic behavior. Furthermore, mortars with ASP revealed a reduction in water absorption by capillarity ability, especially with 4% content, suggesting changes in the microstructure and pore characteristics. The results also demonstrated that an improvement in the physical and mechanical properties of the lime mortars can be achieved when ASP microparticles are previously subjected to dispersion techniques. [ABSTRACT FROM AUTHOR]

Slaked lime is traditionally a suitable material for use in construction activities in historic and traditional buildings whose constitutive characteristics demand compatible and appropriate material solutions. Therefore, knowing the physical and mechanical characterization of lime pastes and mortars for use in restoration is considered an important step in the process of scientific development of a material that, in the Mexican case, has lacked scientific rigor in its production, use and commercialization. With this in mind, the present article aims to investigate the characteristics of lime pastes and mortars that have been used in the traditional way and the new limes that exist in the market, offering suitable options for restoration, for which an integrated methodology was used consisting of physical tests such as surface area, electrical resistivity, pulse velocity, colorimetry, and mechanical tests such as compressive strength, giving as a result that "traditional slaked" lime is more likely to deteriorate than powdered lime, which leads us to conclude that powdered hydrated lime has optimal characteristics for restoration activities. [ABSTRACT FROM AUTHOR]

This study examines the mortar materials used in the construction of the walls at the Archaeological Roman Fortification site (Ovidiu, Romania) on the shore of Siutghiol Lake. Several analyses were conducted to determine the mortars' basic physical properties, mineralogical composition, and microstructural characteristics in order to describe the mortars used in the construction of the Roman fortress. The investigation utilized X-ray diffraction (XRD), energy dispersive X-ray fluorescence spectroscopy (XRF), scanning electron microscopy (SEM-EDAX), and differential thermal analysis (TGA-DTA). The results indicated that siliceous aggregates and lime binders were used in the production of the studied mortars, the structure was constructed in the sixth century, and the raw materials used to construct the site are of local origin. Using the methods mentioned above, there is the possibility of recreating the fortification's mortar formula using contemporary materials and recommending intervention materials for the preservation of the archaeology of the Roman Fortification. Furthermore, this study opens up many other research opportunities regarding the reuse of mortars extracted from archaeological sites in the rehabilitation process by integrating them into new mortar recipes that can then be tested to compare the results with those obtained from standardized recipes. [ABSTRACT FROM AUTHOR]

In every restoration project, knowledge of the mechanical properties of the original materials is considered essential for engineers, not only for the structural assessment of the monument, but also for the selection of compatible restoration materials. In the case of mortars, however, direct or indirect determination of their mechanical properties is usually challenging, due to the limited size and number of available samples. Hence, alternative non- or micro-destructive techniques need to be exploited for the evaluation of the compressive and flexural strength of historic mortars. In this study, the micro-destructive scratching resistance test is used to assess the compressive and flexural strength of a variety of lime-based mortars, that were either designed and produced in the laboratory using different binders, aggregates and admixtures, or sampled in-situ. Sound linear correlations observed between the intrinsic specific energy, resulting from the scratching resistance test, and the compressive and flexural strength of the laboratory designed and produced mortars validate the potential of the scratch tool in assessing the aforementioned mechanical properties of lime-based mortars. This is further confirmed by results on historic mortar fragments. Therefore, the use of the novel micro-destructive scratch tool is recommended in cases where lime mortar sampling is limited, in order to provide reliable estimates for the mechanical properties of historic mortars. [ABSTRACT FROM AUTHOR]

Lime materials are in great demand for the restoration of the walls of historical buildings. However, lime coatings have insufficient resistance during operation. The purpose of this work was the modification of lime mortars with silicic acid sol in order to obtain more durable crystalline materials for construction purposes. A technology has been developed for obtaining a silica-containing additive, which consists in passing a liquid glass solution with a density of 1.053 kg/m3 through a cationic column and obtaining a silicic acid sol with a pH of 3–4 and a charge of (−) 0.053 V. The regeneration time and the amount of sol have been determined. Regularities of change in the radius of particles of silicic acid sol depending on age are determined. It is established that at an early age (up to 5 days), the radius of sol particles can be determined in accordance with the Rayleigh equation, and at a later age, in accordance with the Heller equation. The results of the calculation show that at the age of 1–5 days, the radius of the sol particles is 17.1–17.9 nm, and then the particles become coarser and the particle radius is 131.2–143 nm at the age of 19 days. The work of adhesion of silicic acid sol to lime and the heat of wetting are estimated. It is shown that the work of adhesion of water to lime is 28.9 erg/cm2, and that of the sol is 32.8 erg/cm2. The amount of heat Q released when lime is wetted with SiO2 sol is 15.0 kJ/kg, and when lime is wetted with water, it is 10.6 kJ/kg. [ABSTRACT FROM AUTHOR]

Ammonium carbonate was used as the carbonation accelerator for air-hardening lime mortars in this study. Various analytical methods, including XRD, IR, TGA-DSC and SEM were employed to access the phase transformation, degree of carbonation and microstructural features of the lime-based mortars. The paper explores the correlation between the mechanical strength, microstructure of cured lime mortars and the composition/carbonation degree with the crystallization behaviors in Ca(OH)2/CaCO3 binders. The results indicate that ammonium carbonate significantly accelerates the carbonation reaction and increases the early mechanical strength of air-hardening lime mortars. The mechanical strength of these modified lime mortars can be comparable to that of natural hydraulic lime (NHL). The aggregation behaviors of nano-CaCO3 under kinetic control, are believed to contribute much to the compact pore-structures and robust mechanical strength of lime mortars. This viable accelerating carbonation method holds promise for enhancing the properties of various lime-containing building materials in conservation and modern buildings. • Ammonium carbonate is effective in accelerating the carbonation of aerial lime. • Lime mortars modified by ammonium carbonate rival natural hydraulic lime (NHL). • The mechanical strength is highly related to carbonation degree and pore structure. • Nano-CaCO 3 play pivotal role in compacting the pore structure of lime mortar. [ABSTRACT FROM AUTHOR]

The most used binders for coating and laying mortars are Portland cement and hydrated lime. The hydrated lime has been used for centuries due to its properties. However, the construction field has been modernizing and seeking improvements, which led to the use of industrialized mortars. Those mortars are made from a controlled manufacturing and dosing process and typically do not contain lime. Instead, it contains chemical additives that provide the same properties of lime(workability and water retention), without interfering with the compressive strength. Nevertheless, there are still gaps regarding the performance of these mortars, mainly related to the safety of buildings in fire situations. To evaluate these materials regarding a fire situation, the residual compressive strength was identified as one of the most important parameters. In addition, non-destructive tests, such as the ultrasonic test, has been proved to be a great tool to help in this evaluation. In this context, this work aims to investigate the relationship between the residual compressive strength and the UPV of industrialized mortars and mortars with lime, for usual strength classes (laying and coating mortars) subjected to high temperatures. From the results, lime mortars showed lower values for residual UPV. Moreover, the addition of lime was found to be a relevant parameter in evaluating the residual UPV of mortars, while the strength class, for a range of 5-20 MPa, did not show high relevance, indicating that mortars with and without lime should be studied individually. In addition, unlike many studies that propose a correlation without any standard methodology, this work proposes a correlation following a standard methodology and proves, through a validation with data from literature, that residual UPV and residual compressive strength are correlated through a logarithmic regression. Therefore, this work makes a great contribution by providing an estimation of compressive strength through an NDT testing, helping practitioners to adopt a thumb rule in the lab and in the field, especially in post-fire evaluation. [Display omitted] • The addition of lime is a relevant parameter in evaluating the residual UPV of mortars. • The addition of lime in mortars is more relevant to the microstructure of the mortar than to the f c. • The greater the cracking, the lower the f c of lime mortars. • There is a logarithmic relationship between Residual UPV and Residual f c of mortars. [ABSTRACT FROM AUTHOR]

Liesegang rings have been noticed in laboratory experiments with lime mortars but very few references mention their presence in mortars exposed outdoors. To date, authors have linked the occurrence of Liesegang patterns to mortars prepared with long matured limes, but here we show that very coarse and poor quality lime mortars may also develop similar patterns. SEM observations and EDS measurements on samples taken from exposed mortars show that calcium content varies along the banding sequence, and measurements made along naturally occurring banded patterns prove that the spacing law characteristic of the Liesegang phenomenon applies to them. One case showed that the carbonation banding follows a trendily revert pattern, while a second one fits in an equidistant-type pattern. The occurrence of such irregular patterns may be governed by the presence of a drying process superimposed on the normal diffusion process along the carbonation front. [ABSTRACT FROM AUTHOR]

• The potential of brick waste recycling and its use in aerial lime-based mortars is investigated. • The incorporation of brick dust in lime mortars generated a pozzolanic reaction. • Brick dust improved the compressive strength. • Brick dust increased the hygric and hydric expansion of lime-based mortars. To preserve architectural heritage for future generations, restoration materials such as mortars should be compatible with the historic substrate. Pozzolanic mortars are a compromise solution between Portland cement-based mortars and aerial lime-based mortars. This paper investigates the recycling of brick waste in the Meknes region of Morocco to formulate pozzolanic mortars. Nine different mortars were made using aerial lime, sand and brick dust. They were characterized in terms of shrinkage, color, mechanical and hydric properties. The study revealed that Meknes brick dust exhibits a pozzolanic activity and reduces shrinkage. Moreover, it increases hydric and hygric expansion, enhances mechanical strength and affects the color of mortars. An appropriate recipe for restoration mortars could then be proposed to restore regional architectural heritages, depending on the properties of their historic substrates. [ABSTRACT FROM AUTHOR]

• Lime powder mortars present higher carbonation rate in relation to lime putty ones. • The pore distribution is unimodal for lime powder mortars and bimodal for putty ones. • Water capillary rise coefficient is higher for lime powder mortars. • Lime powder mortars present higher compressive strength compared to putty mortars. • The aggregates' mineralogy does not affect significantly the mortars' characteristics. The aim of this work is to study the influence of calcium hydrated lime (lime putty or hydrated lime powder) to the chemical and physico-mechanical characteristics of lime mortars. The mortars were designed with the same mixing ratio of lime/aggregates and evaluated till 18 months of curing. The carbonation rate is evaluated via DTA/TG, the pore structure by mercury intrusion porosimetry and the hygric properties via capillary rise and water immersion tests. Mortars' shrinkage and apparent density were also measured along with mechanical strength and static and dynamic modulus of elasticity that were evaluated by using conventional mechanical tests and ultrasonic technique. The obtained results revealed that lime powder mortars present a higher carbonation rate and higher values of compressive strength compared to lime putty mortars. Lime powder mortars also exhibit a unimodal pore size distribution (while lime putty mortars present a bimodal one) and higher capillary rise coefficient and porosity accessible to water in respect to lime putty mortars. [ABSTRACT FROM AUTHOR]

• Mortars from the Roman Forum of Carthago Nova show a clear multilayered structure. • The mortars' composition varies considerably across layers (top to bottom). • TG allows quantification of cerussite, whose origin is uncertain in Roman mortars. • Hydroxyapatite linked to combustion of animals' bones was found in black pigments. • The materials are well preserved, and some mortars were likely coated (wax). This paper aims to study the construction technique and characterisation of original mortars and wall paintings at the Roman Forum district of Carthago Nova (Spain). A multi-analytical approach was conducted on original fragments using Optical Microscopy (OM), Field Emission Scanning Electron Microscopy (FESEM), colour tests (CIE L*a*b*) and contact angle measurements. Besides, the chemical composition was studied by X-fluorescence (XRF), Thermogravimetry (TG), X-ray diffraction (XRD) and Infrared spectroscopy using attenuated total reflectance (ATR-FTIR). The mortars showed a multi-layered pattern consisting of three distinguishable layers that were decorated with low-thickness coatings. The top layer composition was eminently calcitic, while the central and bottom layers were probably elaborated with pozzolanic materials. It is worth noting that unusual minerals as cerussite (PbCO 3) were identified in some layers, and probably associated to subsequent activities carried out in the site after Roman times. The top coating was made of hematite (Fe 2 O 3) for red decoration, whereas graphite (C) and hydroxyapatite (Ca 5 (PO 4) 3 (OH)) were identified in black coatings, which suggests the use of animal bones in the production of black pigments. In addition, the outer surface of some fragments was most likely coated with organic substances to enhance colour and durability. Finally, SEM examination and EDX analyses also confirmed some of the above findings and the existence of NaCl surface crusts due to natural weathering. [ABSTRACT FROM AUTHOR]

Abstract The estimation of climate conditions and different moisture sources associated with the substrate composition and features in historical buildings is crucial to evaluate the substrate biodeterioration by filamentous fungi. Knowing the main agents and their frequency in substrates is relevant to propose conservation approaches focused on buildings preservation. Therefore, the mineralogic composition characterization of the historic building mortar coatings in Porto Alegre, RS was performed by binder/aggregate proportioning, x-ray diffraction, x-ray fluorescence, and thermogravimetric analyses. The microclimate conditions of indoor environments were evaluated through relative humidity (RH) and temperature recording sensors measurements. The qualitative and quantitative identification of filamentous fungi from the mortar coating was performed by microculture and DNA extraction for PCR and molecular analysis. The analyses indicated a mortar coating predominated by CaCO 3 and MgCO 3 with quartz sand and traces ratio between 1:2 and 1:5.4. The indoor microclimate had mean RH above 70% and a mean temperature above 20°C most of the time. Approximately 60 colonies of fungi were isolated, and 13 isolates were identified as the most frequent ones; among them: Aspergillus niger, Cladosporium sphaerospermum, Cladosporium spp., Purpureocillium lillacinus, Lecanicillium spp., Trichoderma atroviride, and T. harzianum. Highlights • The correlation between the indoor microclimate and fungal deterioration in a historical building was evaluated. • Different moisture sources influenced the fungal diversity and frequency. • The correlation between the mineralogical composition of historical mortars and fungal growth was estimated. • The fungal molecular identification was performed considering the substrate and regional constraints. [ABSTRACT FROM AUTHOR]

• Comparison of Argical M1000, diatomite and brick dust pozzolans in lime mortars. • Comparison of direct and indirect methods used to determine pozzolanic activity. • Effect of pozzolanic lime mortar pore structure on freeze thaw resistance. • Optimisation of pozzolanic lime mortars for masonry in conservation applications. Degradation of hydrated lime mortars subjected to freezing and thawing is common in historic building conservation. The pozzolanic additions, Argical M1000, diatomite (diatomaceous earth) and brick dust, were evaluated for their ability to improve performance for up to 720 days. Pozzolanic reactions influenced the pore structure evolution, mechanical performance, and chemical reactivity of the mortar matrix. Argical-lime mortars exhibited a sudden failure, while a gradual reduction in mechanical strength was observed for mortars containing brick dust. A slower rate of failure in diatomite mortars was attributed to pore refinement, which was associated with superior freeze thaw performance. This study has advanced the current state of the art regarding how pore structure affects lime mortars' freeze and thaw resistance. Therefore it provides spesifications on how to optimise mortars for historic masonry. A key impact is the more effective use of lime mortars for conservation, thereby protecting heritage structures from degredation. [ABSTRACT FROM AUTHOR]

Two lime mortars were treated under laboratory conditions to assess the potential effectiveness of three consolidation treatments performed with: an ethyl silicate, a nanolime and a solution of barium hydroxide. The consolidation products were applied by direct contact capillarity. The duration and number of applications were adapted to the specific requirements of each product. Compressive and bending strength and drilling resistance were used to assess the potential effectiveness of the three treatments. The mortar made with a larger amount of a coarser aggregate showed lower porosity but a higher proportion of large pores, which was responsible for the observed higher increments in the resistance of the consolidated specimens. Compressive and bending resistance provided information on the consolidation action as a whole, while the drilling resistance measurements allowed also the identification of the consolidated thickness. The ethyl silicate was able to consolidate about 16 mm in thickness, while for nanolime this value only reached a maximum of 5 mm. The treatment with barium hydroxide showed a very distinct behaviour in both mortars reaching a larger consolidated thickness in the coarser mortar, while keeping the resistance increment ratio in a moderate value. The drilling data before and after treatment were interpreted in two ways; (i) with all the tests drilled in a same condition averaged and compared; (ii) after proceeding with a segmentation methodology addressed to identify the binding matrix and to detect the consolidation directly on it. The two methods proved to be complementary ways to characterise lime mortars and to study their consolidation. [ABSTRACT FROM AUTHOR]

The systematic analysis of mortars from monuments or historic buildings and the simultaneous study of the construction environment show that it was common practice to use naturally occurring sand from local rivers or streams for the production of the mortars. There are cases though, mainly on islands, where sands of natural origin were limited, and marine or crushed sandswere used possibly after elaboration. In all cases the particle size analysis of oldmortar confirms the presence of even distribution of the granules. As regards the design of the repair mortars, there are criteria that should be taken into consideration in order to produce materials with compatible properties. The main properties concerning sands are the grain distribution and maximum size, the color, the content of fines, and soluble salts. The objective of this research is the study of the physical characteristics of the sands such as the sand equivalent, the gradation, the apparent density, the morphology of the grains, their mineralogical composition and the influence of these properties on the behavior of lime mortars, notably the mechanical and physical properties acquired. [ABSTRACT FROM AUTHOR]

The use of lime mortar expands several millennia ago and was cited in the architectural feats of all kinds of civilizations. Besides the basic ingredients of hydraulic lime, sand and water, organic admixtures were also added to mortars to modify fresh and hardened state properties as well as its durability. The motivation of the present work is to propose a methodology for the natural replacement of synthetic admixtures by bio-admixtures as repair mortar towards protection of heritage structures. Knowing the use of Cissus glauca Roxb (CGR) in historical mortars, used in ancient temples and monuments in Kerala, it is proposed to give a technical insight to repair the mortar. Moreover, addition of CGR extract is expected to increase the durability' of lime-based mortars used for repair. In the present study, the effect of CGR extract on the properties of lime-based mortars is studied. Mortar's composition is selected with respect to the composition of historic mortars and modern restoration practice. Based on the pilot study CGR extract is added in two different concentrations 15% and 20% by the weight of binder. The consistency of modified mortars, mechanical behavior, water absorption, porosity and water/salt absorption through capillary rise have been measured. Chemical-physical properties of the resulting mortars have been evaluated by X-ray diffraction (XRD), and Fourier Transform- Infrared Spectroscopy (FT-IR) to identify their mineralogical composition and morphology by electron microscopy (SEM-EDAX). It is observed that addition of 15% CGR extract produced maximum positive effect on the strength and durability of lime mortars. It improves the mechanical characteristics and limits water and salt absorption by capillarity into mortar through its hydrophobic nature. [ABSTRACT FROM AUTHOR]

This study presents the preliminary results of investigation of the lime mortars and plasters from archaeological excavations in Hippos (Israel), using Electron Paramagnetic Resonance (EPR) spectroscopy. The research was conducted in order to characterize the building material and its reaction to ionizing radiation. The ancient settlement Hippos, situated on the east shore of the Sea of Galilee, functioned from the 3 cent. BC until it was destroyed by the earthquake in 749 AD. Lime mortars and plasters show carbonate and locally gypsum character of binder and different kind of aggregate. Samples were γ-irradiated and measured using X-band EPR spectrometer. Computer Resolution Enhancement Method was applied to the complex spectra. Some of the γ-induced EPR signals were attributed to CO and CO paramagnetic centres. Exponential growth of the dose response curve above 1 kGy and saturation for doses above 20 kGy was observed. For doses lower than 1 kGy the dose response curve has a linear character. The presence of γ-sensitive carbonate paramagnetic centres could indicate that, after further studies, well-chosen samples of mortars and plasters might be suitable for EPR dating, assuming the centres have been sufficiently bleached during the manufacturing process. [ABSTRACT FROM AUTHOR]

Highlights: [•] Newly-designed traditional lime mortars improving their thermal storage capacity. [•] PCM used as additive improves the thermal insulation properties of the building. [•] Lime mortar+PCM; environmentally friendly and compatible with traditional buildings. [•] Sustainable architecture. [Copyright &y& Elsevier]

This research aims to revalue the possibilities presented by lime mortars for use in renovation and as cladding material on facades. The study focuses on analyzing the technical feasibility of lime mortars with the incorporation of residues from three types of thermal insulation materials: expanded polystyrene with graphite especially suitable for use on facades; expanded polystyrene for use indoors; and insulating mineral wool. The incorporation of these construction and demolition residues makes it possible to improve several technical performance aspects of lime mortars, and to incorporate circular economy criteria in the manufacturing process of these materials. The results showed that the incorporation of mineral wool improves the mechanical resistance to the bending of mortars, increases their durability against freeze–thaw cycles and salt crystallization, and reduces the final shrinkage of mortars. For their part, mortars with the addition of polystyrene-insulating residues reduce mechanical resistance, but also reduce thermal conductivity, and are lighter, which is why they are shown as a possible alternative for use in precast. [ABSTRACT FROM AUTHOR]

• Waste glass and brick dust were valorised in lime-mortars for restoration. • Mortar substrate of the Theatre of Skikda were characterised. • Mechanical and physical criteria for restoration lime mortars are presented. • Experimental testing of repair mortars, compatible for historic buildings. Employing ceramic wastes in lime mortars for the restoration of historic buildings has environmental, cultural, social, and economic benefits. This study deals with the possibility of recycling waste glass powder and brick dust in air-lime mortars for restoration purposes. The theatre of the city of Skikda in Algeria was chosen as a case study. To correctly perform the intervention, the main pathologies and the substrate properties were investigated. Different samples of mortars (structural, plaster, external, internal) were taken from the theatre. Their physical and mineralogical properties were determined. Eleven repair mortars were investigated and waste glass powder and brick dust were added to air lime at different substitution rates: 10, 15, 20, 25 and 30%. The local raw materials used and the mortars investigated, were characterised in the laboratory to obtain their mechanical and physical properties. The results were satisfactory and fulfilled the requirements for the application of these mortars for restoration of the theatre, especially concerning mechanical performance. The mortars that were made up by substituting 30% with the two wastes, presented the highest values with an augmentation of 68.7% for mortars with waste glass powder, and 50.5 % for mortars with brick dust. The compressive strength was augmented. Furthermore, it was found that the mortars can also be used for other historic buildings. The two wastes presented pozzolanic activity and improved the mechanical strength of the mortars. From an environmental standpoint, the use of these ceramic wastes offers many advantages, encouraging their re-utilisation and, consequently, reducing landfill disposal. [ABSTRACT FROM AUTHOR]

Abstract: This study presents the preliminary results of investigation of the types and dynamics of paramagnetic centres in lime mortars from Sveta Petka church in Budinjak, Croatia, using Electron Spin Resonance (ESR) spectroscopy. The excavation in Budinjak discovered a very unique four lobed plan object Sveta Petka, with no additional finds or reliable historical records about the time of its construction. The lime mortars from the church were chosen for analysis in order to characterize the building material and to verify the site chronology by dating them. Lime mortar is valuable but problematic material for luminescence and radiocarbon dating. This type of material has not been dated before using ESR; therefore, careful studies are required to identify the useful paramagnetic centres. The ESR approach suggested in this work concentrates on a calcium carbonate signal. All samples were γ-irradiated in 60C bomb with the doses of 1, 10, 20, 50, 80 and 100kGy. In all spectra signals from Fe3+ and Mn2+ ions have been observed. Paramagnetic centres which give the ESR signals may be interpreted as CO2 −, CO3 −, CO3 3−, HCO3 2−, SO2 −, SO3 −, PO2 − and PO3 2− species. However, all spectra are complex and signals are interfering; therefore, computer resolution enhancement method will be needed in further research. The changes in ESR signals amplitude measured at magnetic field range about 3440–3450G were analysed versus the dose of irradiation, using Mn2+ signals as a reference. Exponential growth of the curve and saturation for doses above 20kGy were observed; therefore, irradiation with smaller doses is required. These preliminary studies will be helpful in future attempts of dating lime mortars by ESR method. [Copyright &y& Elsevier]

Abstract: This paper studies the effect of maturation on mortars prepared according to a traditional method of slaking quicklime mixed with sand and kept wet until used (hot lime mix). Two lime/aggregate weight proportions were considered, a rich one (1:5) and a normal one (1:13). The quicklime was used as pieces of crushed calcined limestone and as micronized quicklime, both from industrial production. The mortars prepared with hot lime were kept wet for periods of 1, 7, 45 and 90days, before moulding, while those prepared with micronized quicklime were matured for 7, 45 and 90days. After the specimens were moulded, their mechanical and water-related behaviour was studied at 28, 90 and 360days. Mercury intrusion porosimetry and SEM observations were performed for some of the mortars to follow the microstructure changes. The aim was to understand the advantages and drawbacks of this traditional process and of a similar process with industrial quicklime. It was concluded that the maturation time has a very positive influence on flexural and compressive strength, cracking susceptibility and water absorption by capillarity. However, the process has also disadvantages, such as time consuming preparation and need of extreme care. [Copyright &y& Elsevier]

Abstract: Lime mortars have been used for centuries in civil engineering construction. Considering ancient monuments and historical buildings it seems that these mortars have proved to be durable and reliable materials although they are of low strength in comparison with cement mortars. Nowadays, they are used for the repair of monuments and for the manufacture of renderings and plasters. In the present paper the role of aggregates on the structure and behaviour of lime mortars is examined by studying the influence of the aggregate content and the grain size on strength, porosity and volume stability of the mortars. Capillary porosity by suction was also measured as an indicator of resistance to weathering. It is shown that coarse aggregates contribute to the volume stability of lime mortars independent of strength enhancement when adequate compaction reduces the capillary pores. The highest strength values, and consequently, the low porosity, were attained by lime mortars of low binder/aggregate ratio which contained aggregates of maximum size 0–4mm. [Copyright &y& Elsevier]

[Display omitted] • Quarry waste added to air lime mortars at 5% and 15% w/w with respect to lime. • Ball milling was applied to the waste to reduce its particle size to the nanoscale. • Mortars with 15% w/w nano-sized waste showed improved carbonation and strength. • Enhancement of carbonation reactions achieved at ambient conditions. The carbonation of air lime mortars modified by the addition of 5% and 15% w/w (in partial replacement to lime) quarry waste, rich in Ca-, Mg- and Fe-silicate minerals, is hereby investigated. Ball milling was initially applied to the waste to reduce its particle size to the nanoscale and increase its reactivity towards CO 2. The incorporation of the nano-sized waste at 15% w/w resulted in mortars with denser microstructure and higher compressive strength. This is attributed to the enhanced diffusion of atmospheric CO 2 through the mortar pore structure and the improved CO 2 uptake of the nano-sized waste additive. [ABSTRACT FROM AUTHOR]

• Brick residues (brick dust, crushed brick) have been diachronically used in mortars. • Their exploitation enhanced resistance to humidity, decreasing density. • The post-fire performance of traditional mortars has to be taken into account. • Three mortar series were manufactured and tested (L, LP, LPB) - 40% of natural aggregates was substituted by crushed brick. • The 90d post-fire testing age results were more representative - Brick residues enhanced the mortar matrix at extreme temperatures. Brick residues, such as brick dust and crushed brick, have been diachronically used in historic mortars, both as binders and aggregates. Their application served as a mean to increase the pozzolanicity of the matrixes, enhancing resistance to humidity, decrease the density of the mixtures and add special hue to the structures. On the other hand, the performance of traditional mortars at elevated temperatures is a significant aspect that should be taken into account, in order to assess the preservation state and residual capacity of historic structures, as well as to design fire resistant restoration materials, under the prism of compatibility. In this study, three mortar series were manufactured, based on lime (L), lime : natural pozzolan (LP-1:1 by weight), lime : natural pozzolan : brick dust (LPB-1:0.8:0.2 by weight). In order to envisage the role of crushed brick in the matrix, they substituted the 40% of natural aggregates in the same gradation (0–8 mm). The physico-mechanical properties of the mortars were tested at 28 and 90 days, while they were further exposed at elevated temperatures, concerning 200 °C, 400 °C, 600 °C, 800 °C and 1000 °C. Their post fire properties (physico-mechanical, microstructural) were recorded, so as to identify the preferable testing age of lime-based mortars and the impact of brick residues on their behavior. From the evaluation of the results, it was asserted that the 90d age seems to be more representative, while crushed brick and brick dust enhanced structural integrity throughout extreme temperatures. [ABSTRACT FROM AUTHOR]

The Church of the Company of Jesus in Quito (1605–1765) is one of the most remarkable examples of colonial religious architecture on the World Heritage List. This church has multiple constructive phases and several interventions with no clear record of the entire architectural site, including the historical mortars. A total of 14 samples of coating mortars inside the central nave were taken, with the protocols suggested by the research team and a comparative sample of the architectural group that does not have intervention. The analysis presented in this paper focuses on mineralogical characterization, semi-quantitative analysis by X-ray diffraction and scanning electron microscopy with microanalysis of the samples. The results showed the presence of volcanic aggregate lime and gypsum, used in lining mortars and joint mortars. Mineralogical and textural composition data have allowed the mortar samples to be relatively dated. [ABSTRACT FROM AUTHOR]

The presented work discusses results of radiocarbon dating of lime mortars sampled from walls of a Romanesque chapel at the Wleń castle. Considering a homogeneous structure of the mortars, an attempt to determine the chronology was made. Radiocarbon dating was carried out both on carbonate binders and laboratory-selected charcoals from the mortars. According to obtained data, charcoal ages are older than the age of the binders. Assuming the 12th century chronology of the chapel's erection to be correct, it was found that the applied method did not provide the result which is consistent with archaeological estimations. [ABSTRACT FROM AUTHOR]

• Pure phase crystalline Mg(OH) 2 nanoparticles synthesis with cationic surfactant CTAB. • Ca(OH) 2 nanoparticles synthesis with non-ionic surfactant Triton-X100. • Lime mortar substrates treated with Ca(OH) 2 and Mg(OH) 2 alcohol nanolime dispersions. • Mechanical properties of nanoconsolidants. • Consolidation effectiveness of treatment with nanolime. This research intends to study and optimize successful preparative strategies of nano to sub-micro limes, and to improve their efficiency in the inhibition of the degradation process and in the consolidation of wall renders. In this article we report the synthesis and characterization of nanoparticles based on alkali-earth metal hydroxides, precisely calcium and magnesium hydroxides nanoparticles (Ca(OH) 2 and Mg(OH) 2) dispersed in ethanol and 2-propanol, for cultural heritage restoration. We discuss the tests conducted to assess the mechanical properties' alteration of lime mortar specimens treated with these nanolimes (superficial hardness, dynamic elastic modulus, compressive and flexural mechanical behaviour). Particularly, the influence of the dispersions' concentration, number of applications (layers) and the slope of the treated surface during the dispersions application on the mechanical properties has been studied. The treatment with nanolime resulted in an improvement of the mechanical properties of the treated specimens. This effect is proportional to the number of layers applied and to the concentration of the alcohol dispersion applied. We also report our attempt to achieve better particles morphology by the addition of surfactants: the non-ionic t -octylphenoxypolyethoxyethanol (Triton X-100) in the synthesis of Ca(OH) 2 and the cationic hexadecyltrimethylammonium bromide (CTAB) in the synthesis of Mg(OH) 2. [ABSTRACT FROM AUTHOR]

• Agglomerating trend of nanoSiO 2 caused less increase in workability than nanoCa(OH) 2. • Adding nanoCa(OH) 2 lowered pozzolanic activity but increased carbonation ratio. • Rate of pozzolanicity increased when nanoSiO 2 was added alone or in combination with nanoCa(OH) 2. • The combined addition of nanoSiO 2 and nanoCa(OH) 2 increased porosity and capillary absorption. • The generation of less stable phases and microcracks decreased the strength but increased deformability. This research presents a novel approach based on the combination of nanotechnology and Roman technology by investigating how adding nanoCa(OH) 2 and nanoSiO 2 modify the performance of air lime mortars containing Roman ceramics. Microstructural, physico-mechanical properties were periodically controlled until 120 days of curing. XRD and TGA analyses showed that adding nanoSiO 2 either alone or with nanoCa(OH) 2 were more beneficial to improve the pozzolanic activity in the mortars. The less stable hydrated phases generated led to microcracks which eventually impaired compressive strength but enhanced deformability capacity. These results provide insight into the development of highly compatible mortars for cultural heritage. [ABSTRACT FROM AUTHOR]