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The paper presents the lithologies used in the stone products of Neviodunum (modern Drnovo in Slovenia), a Roman municipium in south‐western Pannonia. For this purpose, 95 stone monuments were assessed. Petrographic and biostratigraphic analyses were carried out on 56 archaeological and 57 geological samples. Our research shows that, besides some rare exceptions, most stone products refer to three lithostratigraphic units: the Middle Miocene ‘Lithothamnium’ Limestone Member of the Laško Formation, the Upper Cretaceous Krško Formation and the Early Jurassic Krka Limestone Member of the Podbukovje Formation. [ABSTRACT FROM AUTHOR]

This paper aims to bring to light and edit nine Byzantine funerary inscriptions discovered in the town of El-'Irāq (western Governorate of Karak, southern Jordan). All these pieces belong to the period ranging from the 5th to the 6th centuries ce. Like the majority of the inscriptions from the area, these epigraphs consist of short epitaphs engraved on rectangular tombstones made of local limestone and adorned with Christian symbols. The main novelty of this work is the appearance of two anthroponyms that have not been attested to date in the local epigraphic record: Γομολλα and Ἠλίος. [ABSTRACT FROM AUTHOR]

Natural aggregates from sedimentary rock, like limestone and dolomite, are of a great use in various practical applications. To evaluate their quality, among others, the test of methylene blue adsorption (MB value) using a filter paper is recommended. However, one can consider it as a rough test. In this paper we wished to evaluate its quality by comparison with a more precise spectrophotometric method, i.e., to perform adsorption isotherms of methylene blue from aqueous solutions, as well as determine other parameters characterizing the aggregates. For this purpose, methylene blue adsorption on samples of limestone and dolomite natural aggregates having various grain sizes were studied to assess quality (fine particles content) of the manufactured aggregates. To determine the amount of adsorbed dye two methods were used: the methylene blue stain test and the dye adsorption from its solutions at various concentrations under static conditions. From the linear form of Langmuir adsorption isotherms of methylene blue, the monolayer capacity was determined, and then the specific surface areas of all fractions of aggregates. The structural (N2 adsorption/desorption), textural (SEM/EDS) and crystallographic structure of the aggregates were studied. It was determined that the MB values for 0–2 and MBF for 0–0.125 mm aggregates fractions fulfill the criteria set out in the specifications required for pavement construction. A very good repeatability of the adsorbed amount of methylene blue on the dolomite and limestone aggregates were obtained by these two different methods. These results confirm the reliability of the method blue test used typically in industrial conditions. The measured specific surface areas of limestone and dolomite using N2 adsorption (SBET) are smaller than SMB determined by methylene blue adsorption from aqueous solutions. This is because in aggregates, apart from calcite and dolomite, there is a small admixture of quartz and clay minerals. During N2 adsorption in dry condition, the external surface of the grains is determined, while in the aqueous solution of methylene blue, both the external and inner surfaces of clay minerals are determined. [ABSTRACT FROM AUTHOR]

The aim of this paper is to investigate the adhesion of municipal solid waste incinerator bottom ash (MSWIBA) and limestone to asphalt using the principles of surface energy theory. MSWIBA asphalt mixes are known for their satisfactory water stability, with adhesion being a crucial factor, as demonstrated in previous freeze-thaw splitting tests. Contact angles of ground MSWIBA and limestone were measured using a capillary rise test, eliminating the influence of material surface structure. Subsequently, adhesion work and spalling work were calculated to correlate with water-induced damage. The results showed that the sequence of adhesion work was fine MSWIBA > limestone > coarse MSWIBA, while the sequence of spalling work was coarse MSWIBA > limestone > fine MSWIBA. The adhesion of MSWIBA asphalt mixes was evaluated using the water boiling test image method to validate the findings of surface energy theory. In both asphalt tests, the spalling rate followed this sequence: coarse MSWIBA > limestone > fine MSWIBA. The Adhesion index ER ranked as follows: ER Fine MSWIBA > ER limestone > ER coarse MSWIBA. These results suggest that the water stability of MSWIBA asphalt mixes is influenced by the surface energy of the components. Consequently, indices derived from surface energy theory can be applied in formulating and predicting the properties of MSWIBA asphalt mixes. [ABSTRACT FROM AUTHOR]

In this paper, the limestone reservoir of the Upper Permian Taiyuan Formation in the Ordos Basin is taken as the research object. Through various analysis and testing methods, the characterization and classification evaluation of pore structure were carried out. The core porosity and pore structure characteristics were analyzed using nuclear magnetic resonance, gas measurement, and CT scanning. Based on the characteristics of the limestone reservoir, the optimal parameters of NMR testing were calibrated, the NMR testing method of limestone reservoir properties was established, and the NMR porosity of limestone was calculated. Using the core gray map obtained using CT scanning imaging technology, the three-dimensional digital core model of limestone was constructed, its pore space was extracted, and the porosity, pore fractal dimension, and tortuosity were calculated. The results show that with the thermodynamic experiment, the porosity of the sample will remain basically unchanged after 180 min, and the pressure in the sample was measured after 4 h and no air leakage was found. The T2 spectrum of saturated marlite is in the form of three peaks, two peaks, and one peak. On the whole, the p1 peak of the T2 spectrum of limestone corresponds to micropores, and most of the p2 and p3 peaks correspond to mesopores–macropores. The pore size of high porosity samples is 150–350 nm, and the micropores are well developed; the pore size of medium porosity samples is 80–150 nm, and some samples are well developed; the pore size of low porosity samples is mostly bimodal, with two peaks >> 300 nm and <<100 nm. With the increase in depth, the porosity decreases gradually, the fractal dimension decreases, and the tortuosity increases. The research results provide data support for the characterization of the pore structure of the limestone reservoir in the Taiyuan Formation of the Ordos Basin. [ABSTRACT FROM AUTHOR]

The occurrence of subsurface karst caves can cause the development of superficial depressions which, in turn, may pose a construction hazard. Identifying such a substratum requires integrated non-invasive measurement methods. The main objective of the study was to demonstrate the effectiveness of the non-invasive ERT, TLS, and GPR survey techniques in identifying the karst floor and determining the direction of discontinuities around the cave. The paper analyzes the limitations of the methods used in the study of heterogeneous media. These limitations are related to the methodology and measurement conditions, data processing, and interpretation in the context of the resolution and depth range. The study was conducted using the example of the Jaskinia pod Świecami cave, formed in the Sarmatianal calcarenites in Poland. The research confirmed its complex karst-anthropogenic genesis. The cave was formed as a result of the infiltration of rainwater and the dissolution of limestone by groundwater, while the paleokarst forms that are characteristic of it and of the surrounding caves and occur in their vicinity, i.e., narrow ridges called "karst candles", were formed as a result of water circulation during the local permafrost degradation in the middle Pleistocene. However, these forms were modified in the Upper Pleistocene and Holocene, as indicated by ERT images. [ABSTRACT FROM AUTHOR]

Because of the gradual depletion of gravel and river sand resources and restrictions on quarrying activities to maintain the ecological balance, limestone crushed sand with a high content of limestone fillers is being explored to be used, as an alternative source of supply, in Portland cement concrete (PCC) for rigid pavement. This paper aims to first present mechanical test results carried out on three types of PCC formulated with crushed limestone sand as fine aggregates, devoid of superplasticizers. Since shrinkage cracking is an important problem for rigid pavement, the shrinkage behaviour of these concretes is then experimentally investigated. Furthermore, three existing models (ACI-209, Eurocode2, and triple-sphere models) and a novel-developed model are used to estimate the mixtures' shrinkage. Results showed that the designed mixtures exhibited normal shrinkage values. The shrinkage modelling revealed that the proposed model well fitted the experimental data. Besides, Eurocode2 and ACI-209 models may be adapted for the case of limestone concretes containing a high content of limestone fillers and then used to accurately estimate their shrinkage strains. However, the triple-sphere model was unsuitable for these concretes and overestimated their ultimate shrinkage since it does not take into account their high filler content. Nevertheless, by adjusting the paste shrinkage expression, the ultimate shrinkage strain values of the tested mixtures were improved. [ABSTRACT FROM AUTHOR]

Limestone is commonly used in cement concrete due to its unique nature and type. It has physical effects (nucleation effect and dilution effect) and chemical effects on the hydration process of cement. This paper reviews the effects of three representative limestone materials on the hydration process, hydration products, and hydration kinetics. In the hydration process, the reaction was delayed by limestone powder with a particle size larger than 20 μm and calcium carbonate whiskers due to their dilutive effect. On the other hand, limestone powder with a particle size smaller than 20 m and calcium carbonate nanoparticles facilitated the reaction through nucleation and chemical effects. Limestone has a similar effect on hydration products, promoting the production of C-S-H through nucleation. The mechanism of action for this nucleation effect depends on the differences in crystalline form and particle size of the three types of micro- and nano-calcium. Chemical effects impact the amount of AFt produced, with the generation of new products being the main reaction influenced by the limestone admixture. [ABSTRACT FROM AUTHOR]

Considering its size and ruins, Sagalassos is an important Pisidian city that has yielded a great number of finds, providing information on a wide range of topics, including funerary practices. In this article, a funerary altar found in Ağlasun (Ağlasun District of Burdur Province) and stored in the depots of the Sagalassos excavation house will be discussed in terms of its typological, iconographic, epigraphic and decorative elements. The grave altar is rectangular in form and made of local limestone. It is known that grave altars of different forms and featuring various figures and decoration elements were used as grave markers in the necropolis for libations and identification of the dead within the framework of the cult of the dead. The object examined in this paper had a similar function. The reliefs present on the shaft of the altar have been interpreted iconographically in the light of the present inscriptions. According to the information obtained from the inscription, the altar was built on behalf of a family. The names of family members are written on the front and right side. Therefore, the figures depicted on the same side can most probably be identified as the mentioned family members. While the open parchment roll indicates education, the depicted phiale is a vessel typically used for ritual libations. Based on our typological, stylistic and iconographic evaluations on the object, as well as the inscription, the altar can be dated to the 3rd century AD. [ABSTRACT FROM AUTHOR]

The current building industry is essentially changing due to implementation of new approach, which is predominantly motivated by the need to reduce its negative environmental impact. The paper is focused on the experimental evaluation of carbonation resistance in terms of accelerated tests performed on the concrete on the basis of blended binding system incorporating milled limestone. The used commercially produced cement was additionally modified by the limestone powder. The obtained results confirmed, that currently used design standards are convenient to real carbonation process, however further clinker replacement by the milled limestone causes significant loss of the durability of the hardened concrete. [ABSTRACT FROM AUTHOR]

The Balkan region is rich in limestone deposits, which have created one of the largest hotspots of subterranean biodiversity. This paper gives an overview of the diversity of subterranean terrestrial arthropods in Resava Cave in eastern Serbia. This cave is protected and has the status of a natural monument. At the same time, it is one of the most visited caves in Serbia and its surroundings. Our study comprises the results of three years of biospeleological investigations of the famous Serbian cave in combination with data from the few available literature sources on the arthropod fauna of the cave. The arthropod samples were collected both manually and with pitfall traps. A total of 107 arthropod species from the four major subphyla were registered in the cave: 66 species of Hexapoda, 27 species of Chelicerata, 11 species of Myriapoda and three species of Crustacea. For four troglobitic, 16 troglophilic and 87 trogloxenic species recorded in the cave, descriptions of their microhabitats and information on their distribution in the cave are given. Considering the medium size of Resava Cave and the lack of permanent water flow in the two main levels on the one hand, and the large number of arthropod species recorded on the other, the cave is relatively rich in hypogean terrestrial arthropod fauna compared to other caves in Serbia that have been biospeleologically studied so far. [ABSTRACT FROM AUTHOR]

This paper conducts a critical evaluation of the applicability of traditional methods and neural network-based methods in separating pore space from the matrix on computed tomography (CT) scanning images of two types of coral reef limestone specimens with coarse and fine pores. By comparing with the manually labelled "ground truth," it is shown that the Otsu method and other traditional methods have good segmentation accuracy and high efficiency when subjected to specific image preprocessing schemes, but their robustness is poor. UNet neural networks with a mixed contrast training dataset have high accuracy and strong robustness, but they are complex and computationally expensive. The three-dimensional reconstruction and analysis of the spatial distribution of porosity shows that the coral reef limestone specimen with coarse pores has a clear pore structure, while the rock matrix and pores are interlaced in the specimen with fine pores. Last, the statistical analysis of porosity and the pore distributions prove that the segmentation accuracy has a significant influence on the subsequent pore analysis. The current study highlights the importance of using appropriate image segmentation schemes and provides useful guidance for future interpretation of pore structure features of coral reef limestone based on CT scanned images. [ABSTRACT FROM AUTHOR]

The genus KirinuaLi & Lin, 2021 belonging to the family Symphytognathidae was established based on the type species, Kirinua maguaiLi & Lin, 2021. A total of three cavedwelling Kirinua species were recorded from Guangxi, China. In this paper, another new troglobitic spider species from the limestone Jinlong Cave in southern China is described under the name Kirinua jinlong sp. nov. Detailed descriptions, illustrations, and diagnosis are given to this new species, as well as a distribution map for all known species of the genus Kirinua. [ABSTRACT FROM AUTHOR]

The Generalised Hoek-Brown (GHB) failure criterion is one of the most used criteria to study the behaviour of the rocks; affected parameters of the Hoek-Brown equation are Geological Strength Index (GSI), intact rock constant (mi), and Disturbance factor (D). GSI is one of the rock classification systems used to evaluate jointed rocks. In light of this equation, this paper studies the stability of unsupported twin tunnels in a weak rock by changing the mentioned parameters (GSI, mi) to find the relation between the stability and these parameters under different distances between the centres of the tunnels (L). The tunnels have a circular cross-section with a diameter (B), and they have been modelled in three dimensions using Rocscience software package (RS3). The results showed that the stability of the tunnels, which was represented by the strength reduction factor (SRF), increased as a result of increasing L/B or GSI in the studied range; for mi, the modelling results showed that the SRF value increased while mi value was increased. [ABSTRACT FROM AUTHOR]

Conventional convolutional neural networks (CNN) are deficient in the rock type recognition due to large convolutional kernels and numerous network parameters necessitated for recognition of complex images. The advanced convolutional neural network, Visual Geometry Group-16 (VGG16) model, which is based on multiple small convolutional kernels and fully connected layers, attains higher classification accuracy, yet is limited by low computational efficiency. In this paper, we propose a novel approach that integrates the advanced VGG16 with the Principal Component Analysis (PCA), a dimensionality reduction technique. This integration, referred to as the PCA-VGG16 model, aims to enhance the computational efficiency of automatic rock type identification. A dataset comprising 3000 images of six rock types: limestone, shale, dolomite, quartzite, marble, and granite, is assembled for training and testing of the PCA-VGG16 model. The feasibility of the PCA-VGG16 model for classification prediction is demonstrated through evaluation metrics including accuracy, loss value, and F1-score. A comparative analysis with the CNN and VGG16 models reveals that the proposed PCA-VGG16 model exhibits superior classification accuracy and reduced training durations, making a very promising advancement in the field. Furthermore, an in-depth analysis is conducted to understand the impact of dataset size and key hyperparameters (such as epochs and batch size) on the classification accuracy of the PCA-VGG16 model. The findings indicate that a minimum dataset of 1500 sample images is necessary to achieve a classification accuracy above 90%. For optimal model performance, a division of training, validation, and test sets approximately at 6:2:2, along with two epochs and a batch size of 128, is recommended in this study. [ABSTRACT FROM AUTHOR]

This paper presents the preliminary results of an investigation on the unexplored topic of polychromy on provincial stone sculptures from the Roman provinces in Germania through the innovative application of heritage materials science techniques. A group of three life-sized statues dating to the 1st Century CE recovered from Ingelheim, near Mainz, retains remarkably well-preserved traces of pigments. These are ripe for emerging non-invasive technologies supplemented by micro-sampling to validate results and provide information relating to mixing and layering not available to the naked eye. The most strikingly visible areas of extant polychromy were retained on the sculpture of a young woman, reported on here as the first phase of this programme of research. The results suggest that the statue was originally covered in a gypsum layer before the application of complex and diverse recipes of pigment applied as mixtures and in layers to create required hues and shadowing on sculpted features. The palette includes ochres and green earth mixed with small amounts of minium (red lead), realgar and lapis lazuli (ultramarine blue) added to create skin tones, and a vibrant blue-green tunic created from Egyptian blue, bone black, ochres, cinnabar and green earth; the palla and peplos contained ochres, bone black, and orpiment, and mixes of these created the detail of coloured jewellery. Of great interest was the detection of bone black on many features, particularly as a shading agent to enhance sculpted features, such as folds in cloth, providing a more realistic and flowing articulation. This is a revolutionary observation that provides previously unexplored insights into artistic polychromic practice in Antiquity. [ABSTRACT FROM AUTHOR]

In this paper, we report on a biostratigraphic, magnetostratigraphic, and stable isotope (δ13C and 3He) analysis across three pelagic limestone sections of the Campanian Scaglia Rossa Formation exposed in the classic Bottaccione Gorge at Gubbio (Umbria region), near the village of Furlo, and near the town of Apiro (both in the Marche region), all located in the Umbria-Marche basin of the northeastern Apennines of central Italy. These sections record the coincidental occurrence of an extraterrestrial 3He (3HeET) anomaly known as K1 and a negative shift in the δ13C record known as the early Campanian event. Cyclostratigraphic spectral analysis of the Furlo section based on a highresolution magnetic susceptibility record in these pelagic limestones revealed that the regular orbitally forced Milankovitch cycles are somewhat disturbed or blurred through the interval of the coincident 3HeET K1 anomaly and the early Campanian event isotopic anomaly, suggesting a causal effect resulting from the enhanced influx of extraterrestrial material (i.e., interplanetary dust particles and a myriad of small meteorite impacts). This would have altered the transparency of the atmosphere, causing a short-lived climate change event. [ABSTRACT FROM AUTHOR]

Using limestone powder (LP), the by-product of manufactured sand, to replace part of fly ash (FA) or manufactured sand could not only turn waste into treasure and decrease the price of concrete, but could also enhance the performance of concrete and reduce environmental pollution. However, the impact of various LP incorporation methods on the performance of mass concrete was inconsistent. In this paper, the effects of LP on the workability, compressive strength, constrained expansion rate, hydration temperature and impermeability of mass concrete were studied by replacing FA or manufactured sand alone and replacing FA and manufactured sand simultaneously. The results showed that the impact of LP on the performance of mass concrete was equal when it replaced FA alone and FA and manufactured sand at the same time. When the replacement amount was 20%, the workability, expansibility and early strength of concrete were improved, but the later strength and impermeability were slightly reduced. The workability, compressive strength, expansibility and impermeability of mass concrete were improved when manufactured sand was replaced alone, and the optimal dosage was 10%. The LP, moreover, reduced the hydration temperature peak of concrete in three kinds of mixing methods, but the temperature peak appeared earlier. At lower dosages, LP optimized pore structure and promoted the early hydration of cement through filler effects and nucleation effects. When LP replaced manufactured sand, the microstructure of concrete was more dense, so the replacement of manufactured sand had a better effect on the improvement of concrete properties. A reference value for the use of LP in mass concrete is provided in this study. [ABSTRACT FROM AUTHOR]

In this paper, the effect of ternary binder containing Portland cement type I (PCI), slag, and limestone (LS) powder in varying proportions on the suction development and the mechanical strength of cemented paste backfill (CPB) was investigated. Mechanical tests, microstructural analyses (thermo-gravimetry analysis (TG/DTG) and mercury intrusion porosimetry), and monitoring (suction, electrical conductivity, and temperature) experiments were conducted on CPB. In the first part of this study, binary binders with two different PCI:slag proportions, 50:50 and 80:20, were examined with no LS, followed by the slag replacement with increasing weight percentages of LS from 0% to 20% by weight of the total binder, with constant cement content. The results indicate that the slow slag hydration kinetics decreased the suction and strength gain rate at a young age in the binary sample with high slag content (50 wt.%); however, its latent hydraulic and pozzolanic properties enhanced the strength gain at a later age, from 28 days. The addition of 5 wt.% and 10 wt.% LS to the ternary binder system improved the early age strength of CPB up to 7 days and 1 day, respectively, compared with the binary control samples, i.e., CPB with slag and without LS. While the addition of up to 10% LS to the ternary binder improved the rate of suction development and increased suction at early ages, beyond 10%, the addition of LS slightly decreased mechanical performance at all ages. Overall, the results obtained reveal that up to 50 wt.% slag with up to 10 wt.% LS with cement could be used as a ternary binder to improve the early age strength and suction development rate of CPB studied without significant loss in compressive strength at advanced ages. The results of this research could be of great benefit to the mining industry through the use of a ternary binder to replace cement, which could improve the overall performance of the CPB system, facilitate a more sustainable CPB design, and improve tailings management practices and overall economics. [ABSTRACT FROM AUTHOR]

Understanding of the geodynamic evolution of the Tethyan realm cannot be complete without paleogeographical reconstructions of the North Qiangtang Block (NQB) that occupies a central position in Tibet. However, the reliability of such a reconstruction for the Paleozoic still requires substantial improvement. In this paper, we present paleomagnetic results obtained from the Middle Permian limestones and Upper Permian volcanic rocks in the Tanggula area, aiming to provide precise constraints on the NQB kinematics during the geodynamic evolution of the Tethys realm. Combined with other available paleomagnetic data from the NQB, our results suggest that the block was stably located at ~24°S for a long time before the Middle Permian, started to drift rapidly northward in the Middle Permian, and reached ~8.4°S in the Late Permian. The NQB continued drifting rapidly northward during the Triassic until merging with the southern margin of Eurasia in the Late Triassic. We reviewed new and available paleomagnetic and geological data and proposed a revised model for the tectonic evolution of the eastern Tethys realm. The NQB likely belonged to a ribbon-like separate continental archipelago in the middle of the Paleo-Tethys Ocean during the early--late Paleozoic. The Cimmerian continent, including the South Qiangtang Block (SQB), rifted away from the northern margin of Gondwana and drifted northward to ~22°S in the Middle Permian. The continent approached or partially collided with the NQB, resulting in the rapid northward movement of the NQB and the formation of the Longmuco--Shuanghu suture between the NQB and SQB. [ABSTRACT FROM AUTHOR]

There is a lot of evidence that people used stone in the construction of buildings, as well as for other purposes in the municipality of Livno throughout history, as evidenced by numerous archaeological finds. Ever since the Bronze and Iron Ages, and through the Roman, medieval and Turkish periods, stone has been the main building material in these regions. In recent times, two dimension stone quarries have been opened on the territory of the municipality of Livno, one in the locality of Pogledala, east of the city, and the other in the locality of Kik, located between the Kamešnica and Dinara mountains. Both quarries were opened in massive limestones of Upper Cretaceous age. High-quality limestone with the commercial name "Silit light" is being exploited at the Pogledala quarry, and at the Kik site exploitation has been interrupted, but there is a great possibility of its continuation. [ABSTRACT FROM AUTHOR]

Advanced drilling was employed for the ongoing excavation of a tunnel on Wu-Kai Expressway in Chongqing, aiming to characterize the ground condition ahead of the tunnel face and avoid potential geohazards. Measurement While Drilling (MWD) system and the hydraulic rotary crawler drilling machine are used for the advanced drillhole in the weathered argillaceous limestone rock mass. However, the MWD data exhibits random variations in penetration rate and cannot be correlated with ground conditions. In addition, there is little MWD data on the weathered argillaceous limestone with time-series algorithm in relevant open literature. This paper presents further analysis of the MWD data, resolves the random variation issue in penetration rate, and re-interprets the MWD data along three advanced drillholes in this tunnel project. The re-calculated penetration rate with the time-series algorithm for each drillhole is a stepped function of the drillhole depth. The constant penetration rates for the different homogeneous zones can be further correlated with the weathering degrees of the rock and compared with those from other five ground sites with different ground conditions in China and London. The findings of the paper can enhance the general applicability of MWD data for accurate profiling of weathered argillaceous limestone rock mass for safe tunnelling. [ABSTRACT FROM AUTHOR]

Recognizing the challenges of low strength, inadequate cementation, significant pore development, and excellent connectivity of reef limestone, as well as the persistent issues of 're-leakage' and increasing leaks when using rigid bridge plugs, this paper posits the use of materials possessing both flexible and rigid properties for the prevention of leaks and plugging in reef limestone formations. Consequently, a plugging material exhibiting external flexibility and internal rigidity is developed (EFIR Material). This synergistic approach employs the deformability of flexible materials and the skeletal support of rigid materials to create a high-strength, dense plugging section. The new design enhances the formation's pressure-bearing capacity while effectively addressing leakage issues. The material's functional structure design, a core-shell structure of EFIR, is achieved by reverse-phase suspension polymerization of acrylamide (AM), 2-acrylamide-2-methylpropanesulfonic acid (AMPS), and alkyl ketone polymer (NVP), water-soluble monomers functioning as the shell and modified sand as the core. The results indicate that EFIR retains significant flexibility and strength upon water absorption and expansion. A sand bed made from 10 to 18 mesh calcareous sand exhibits excellent sealing properties. The optimal dosage of 3%-4% produces robust sealing effects, withstands pressures up to 7 MPa, and results in a tightly cemented, high-strength sand bed post-sealing with reef tuff, displaying high-quality sealing that is resistant to re-leakage. [Display omitted] [ABSTRACT FROM AUTHOR]

Cement manufacturing, a fundamental process industry characterized by high CO 2 emissions, sees over 58% of its emissions stemming from the limestone calcination process. However, this significant source of CO 2 has not yet been adequately addressed by most existing cement decarbonization processes. As such, systematic environmental and economic comparisons between different cement processes are essential. This paper proposes a new cement process (NCP) that uses natural gas to react with limestone to reduce CO 2 emissions and simultaneously produce high-value-added chemical products (methanol). To explore strategies for further improving the performance of the CO 2 emission reduction, two processes are developed, integrating the organic Rankine cycle (ORC) and carbon capture and storage (CCS) units with the traditional cement process (TCP) and the NCP, namely TCP-ORC-CCS and NCP-ORC-CCS respectively. Life cycle assessment (LCA) and economic analysis were performed on the TCP, NCP, TCP-ORC-CCS, and NCP-ORC-CCS processes, revealing their advantages and limitations in different scenarios. LCA adopts the "cradle to gate" system boundary, which includes the whole cement process from ore mining to clinker generation and other processes used for carbon reduction. The LCA results show that four cement processes exhibit different environmental performances when choosing different allocation methods. Under economic allocation, the global warming potential (GWP) of TCP, NCP, TCP-ORC-CCS, and NCP-ORC-CCS are 933, 300, 432, and 194 kgCO 2 eq/ton·clinker, respectively. The comprehensive analysis indicates that NCP has the best comprehensive economic and environmental performance when natural gas and methanol prices are 332 and 319 $/ton, respectively. The price fluctuation of natural gas and methanol is found to greatly impact the levelized cost of clinker (LCOC) of NCP through sensitivity analysis. NCP is economically preferred over TCP when the price of methanol (MeOH) is at least $76 above approximately two-thirds of the price of methane (CH 4). Similarly, NCP-ORC-CCS is more advantageous than TCP-ORC-CCS when the price of MeOH is at least $87 above nearly two-thirds of the price of CH 4. This study provides a comprehensive analysis for low-carbon cement process design to achieve CO 2 emissions reduction. [Display omitted] • Detailed designing and modeling of the low-carbon cement processes. • Adopt CH 4 to calcine limestone, producing syngas and CH 3 OH for carbon reduction. • A framework of life cycle environmental and economic assessment is established. • NCP's GWP and LCOC are 67.84% and 20.79% lower than TCP under specific conditions. • Price fluctuation of CH 4 and CH 3 OH strongly impacts the LCOC of NCP-based. [ABSTRACT FROM AUTHOR]

The benefits of limestone waste as a partial replacement of cement have been well established. In this paper, to better understand the effect of limestone waste on the properties of cement-based materials, the hydration process and microstructural properties of cement are evaluated. The results showed that the limestone waste decreased the fluidity of cement mortar, while the mortar having up to 10 % limestone waste provided competitive properties with pure cement mortar. It is concluded that the presence of limestone waste has both negative and positive effects simultaneously on the hydration and microstructural properties of the cement paste. During the hydration process, the net reaction heat of limestone waste in the cement blends ranged from 0.38 J/g to 4.1 J/g. In addition, the thermodynamic modeling and XRD indicated that the monocarbonate and hemicarbonate were stable in the limestone-cement blends, and the limestone waste increased the stability of ettringite. • The effect of limestone waste on the hydration and strength development of cement was investigated. • The net reaction heat of the limestone fines in the cement system was 3.5 J/g∼4.1 J/g. • An appropriate content of the limestone waste improves the chemical shrinkage of cement. [ABSTRACT FROM AUTHOR]

This paper focuses on the study of the reaction between limestone and sodium hydroxide solution. This reaction is used to produce alkali-activated mortars after curing and in the presence of unreactive siliceous sand. The kinetics of this reaction is investigated by semi-adiabatic calorimetry experiments. The formulation parameters are fixed but the curing parameters are tested: temperature (38 and 45°C) and time of drying (14, 25, 27 and 28 days). Their impact on reaction products (identified by FTIR and thermal analysis), on microstructure (SEM observations and porosity measurements) and on mechanical strength (flexural and compressive tests) are determined. The reaction was fast and a temperature drying was required to obtain stabilized hydration products in mortars. The products of the alkali-activation of limestone are double sodium/calcium carbonate (mainly pirssonite and with specific conditions of curing gaylussite) and calcium hydroxide. The microstructure and the proportions of reaction products, impacted by drying conditions, influence the mechanical strength of mortars. With an appropriate time (25 days) and temperature of drying (45°C), the compressive strength reached, after 28 days, almost 25 MPa. • The reaction between limestone and sodium hydroxide solution take place in two stages. • FTIR measurements allow the identification of stages of the reaction process. • Drying in the curing process is necessary to end the crystallization stage. • Curing temperature plays an important part in the nature of reaction products. • The microstructure and the strength of alkali-activated mortars are linked to the curing process (time and temperature). [ABSTRACT FROM AUTHOR]

Turritelline gastropod-dominated assemblages (TDAs) are common in siliciclastic facies from the mid-Cretaceous to the Recent, but their distribution in carbonate facies has been thought to be limited to the Cretaceous and Paleogene, except for "cool-water" carbonates from the Miocene of Australia. This paper describes a TDA in a Pliocene limestone in northern Chile, the only known Neogene TDA limestone from outside Australia. This Chilean TDA probably formed in conditions of relative low temperatures and high productivity, and thus appears to support the hypothesis that TDAs largely disappeared from warm waters after the Oligocene. It is also possible, however, that it formed in conditions of warmer temperatures associated with upwelling during the Early Pliocene warm interval. • A turritelline gastropod-dominated assemblage from Chile is Early or Late Pliocene. • The limestone assemblage is a rarity in the Neogene, when most are in siliciclastics. • The assemblage formed under high-productivity conditions. • If Late Pliocene, conditions were cool water upwelling, unusual for a limestone. • If Early Pliocene, they were non-uniformitarian warm water upwelling in a warm ocean. [ABSTRACT FROM AUTHOR]

North China type coalfield are gradually mining deep, and the mixing of groundwater is intensified. Hydrogen and oxygen isotopes are important elements for tracing groundwater movement. The fractionation response mechanism under mining conditions is not clear. In this paper, combined with numerical simulation, MixSIAR isotope mixing model and other methods, according to the δD, δ18O and hydrochemical information of various water bodies, the impact of coal mining on hydrogen and oxygen isotope fractionation is analyzed from multiple perspectives. The results show that summer soil water is the main source of recharge for limestone water, accounting for 30.7%–41.5%, and the Zhan River is the main source of recharge for limestone water. Before groundwater recharge, evaporation leads to the increase of δ18O in surface water by 0.31‰–5.58‰, water loss by 1.81%–28.00%, the increase of δ18O in soil water by 0.47‰–6.33‰, and water loss by 2.74%–35.80%. Compared with the coal mining layer, the degree of hydrogen and oxygen isotope drift and water-rock interaction in the coal mine stopping layer are significantly improved. The results of numerical simulation show that the pumping activity reduces the 18O concentration in the mining layer. The ion ratio is used as a new variable to eliminate the influence of water-rock interaction when calculating the mixing ratio. The results show that the limestone water is in a state of receiving external recharge, and mixing effect increases the δ18O in limestone water by 0.86‰ on average, and the δD increases by 0.72‰ on average. The research results explain the controlled process of hydrogen and oxygen isotope fractionation under mining conditions, which is of great significance to coal mine safety production. • The contribution ratio of surface water and soil water to limestone water in different seasons was estimated. • Summer soil water is the main recharge source of limestone water. • The mixing effect increases δ18O and δD in limestone water. • The isotope exchange and water-rock interaction in coal mine stopping layer are stronger than coal mining layer. • High temperature does not promote the drift of 18O in limestone water. [ABSTRACT FROM AUTHOR]

Limestone of the purity mandated by the standards for use in cement manufacture (as raw material or as performance improver) is only a fraction of the mined material. Sometimes, limestone contains impurities like silica, clay, dolomite etc. beyond the levels specified for use as an additive or for cement production. This limestone, commonly known as low-grade limestone, also may have a potential to be used as a supplementary cementitious material. This paper reports a study conducted to understand the hydration behaviour of ordinary Portland cement in combination with low-grade limestone. Low-grade limestone samples with dolomite, silica and clay impurities were collected from various limestone mines in India and used in cementitious blends at various replacement levels after suitable processing. Reaction kinetics was studied using calorimetry and phase assemblage using techniques like X-ray diffraction and thermogravimetry. Mercury intrusion porosimetry was employed to study the microstructure of cementitious blends. Dilution effect of low-grade limestone was studied by measuring compressive strength of cement mortar cubes for various replacement levels. Shortening of induction period, increased peak heat rate and reduced time to peak were observed in the blends of ordinary Portland cement with low-grade limestone. Carboaluminate formation, ettringite stabilisation and higher bound water content were also seen. The studies showed that low-grade limestone also can be used as a partial replacement for ordinary Portland cement without compromising the strength up to 15% replacement. Higher replacement levels, although showing a reduction in strength due to dilution effect, could still be considered for non-structural applications. • A systematic assessment of the effect of low-grade limestone with different types of impurities on the hydration of ordinary Portland cement is done. • Similarities and differences in the behaviour of OPC blended with cement-grade and low-grade limestone are brought out. • Non-cement grade limestone, or low grade limestone, can efficiently be utilised as SCM with up to 15% replacement of OPC. [ABSTRACT FROM AUTHOR]

Coal gangue (CG), a byproduct of coal washing and mining, has experienced a substantial increase in production in tandem with rising energy consumption trends. The utilization of calcined CG as an additive to cementitious materials is considered a potentially effective strategy for CG management and expanding its applicability on a large scale. This research investigates the impact of calcined CG on the characteristics of blended cements by applying isothermal calorimetry, X-ray diffraction (XRD), Mercury Intrusion Porosimetry (MIP), and mechanical assessments. This paper investigates four separate binder systems: Ordinary Portland Cement (OPC), OPC incorporating 30 % calcined CG, OPC with 15 % limestone addition, and limestone calcined clay cement (LC3). The XRD analysis of the hydrate phase assemblage indicated that the hydrates in LC3 systems exhibit a notable increase, consequently leading to a significant reduction in porosity by MIP results. Furthermore, LC3 systems show greater refinement in pore structure compared to other blended cements. These findings present novel opportunities for furthering the utilization of coal gangue and extending the applications of LC3 cement. • The calcined coal gangue was successfully applied to fabricate limestone calcined clay cement. • The properties of LC3 systems are better than OPC incorporating calcined coal gangue. • The hydration kinetics is applied to understand the hydration reaction process and the reaction rate. [ABSTRACT FROM AUTHOR]

In cement suspensions, a part of the superplasticizers measured as adsorbed by solution depletion, is actually consumed uselessly by intercalation, coprecipitation, micellization and/or modification of early hydrate surface area. This amount is often referred to as lost, as it is not effective as a dispersant. Despite extensive research on the subject, mechanisms responsible for this remain unclear. With a focus on polycarboxylate superplasticizers (PCEs) and Ordinary Portland cement (OPC)-limestone blended cements, this paper proposes a "direct and delayed dosing (D3)" method to shed new light onto this age-old question. Thereby, the amounts of lost PCE are shown to be proportional to the amount of PCE included in the mixing water and to result directly from an increase in specific surface area. [ABSTRACT FROM AUTHOR]

• The failure mechanism of the Xiaba tunnel collapse was successfully revealed. • A series of effective stabilization measures have been successfully proposed. • The process of prevention and treatment of tunnel collapse has been proposed through field investigation of the Xiaba tunnel. With the increasingly complex environment faced by tunnel construction, the occurrence of collapse accidents has become more frequent. Nevertheless, there still needs to be a deeper realization of its mechanism and prevention measures. Based on this, this paper made a real-time tracking of the Xiaba tunnel collapse through field investigation and monitoring. Then, the specific failure mechanism was analyzed, and a series of comprehensive treatment measures were proposed. The findings indicated that the intricate geological conditions and continuous rainfall contributed to the occurrence of the disaster. To prevent further deformation of the surrounding rock, numerous stability countermeasures were implemented, such as pipe shed, small pipe grouting, temporary arch protection, peripheral radial grouting, and double-layer primary lining support structures. In addition, on-site monitoring data confirmed the effectiveness of these treatment measures. This case has important reference for preventing and treating tunnel collapse accidents. [ABSTRACT FROM AUTHOR]

Two economic activities have been integrated in southern Brazil: olive cultivation and sheep farming. The favorable edaphoclimatic conditions in the southern region for cultivating olive trees and cultural preferences for the consumption of sheep meat make this integration a valuable strategy. Considering that every activity causes environmental impact and the exploitation of natural resources, new systems that promote sustainable development and the efficient use of these resources become necessary. This paper presents the first study of the carbon footprint of the life cycle of integrating of sheep and olive farming, with the objective to build an inventory based on primary data collected on olive and sheep farms in Brazil, determine the carbon footprint of the conventional and integrated system and estimate the potential for mitigating GHG emissions. The evaluation was performed using the life cycle assessment (LCA) methodology. The study focuses on the detailed analysis of the processes and activities that are responsible for GHG emissions, including enteric methane emissions, methane emissions from manure management, emissions from nitrogen fertilizer use and limestone application and energy consumption. For this, two major scenarios were considered, the first centered around on the traditional olive cultivation and sheep farming systems individually, and the second involved their synergistic integration. The findings indicate that the conventional system is associated with a global warming impact of 6.8 kg CO 2 eq per liter olive oil and kg live weight. In contrast, the integrated system demonstrates a significant mitigation potential of 27.7%, resulting in a reduced global warming impact of 4.92 kg CO 2 eq. This advantage is a consequence of the synergy between the systems, as they now occupy the same area, which allows the sharing of agricultural activities and agrochemical inputs, in addition to optimizing nutrient recycling and complementing each other. Additionally, the results of a sensitivity analysis showed that enteric methane from sheep and the application of limestone to the soil are the most influential parameters on the carbon footprint, indicating that they are key parameters for the development of GHG mitigation strategies, some of which were discussed in the article. • First life cycle assessment of integration between olive and sheep farming in Brazil. • The inventory was constructed with primary data collected in situ. • The study assesses the carbon footprint of the olive and sheep farming system. • The results show environmental advantages of the integration of olive and sheep farming systems. [ABSTRACT FROM AUTHOR]

The purpose of the present study is to investigate the mechanical properties, mainly wave velocity, strength, deformability and degradation characteristics of carbonate fault rocks in the laboratory. The investigated materials present a complex behavior, mainly controlled by their tectonic disturbance, which has not been thoroughly studied due to practical limitations in sampling preparation and execution of laboratory tests. A novel procedure to prepare samples from the studied rocks was successfully performed. Two (2) intact, parent rock types (i.e., intact limestone, intact limestone-dolomite breccia) and five (5) fault rock types (i.e., two types of limestone fault breccias, two types of fractured marly limestones and one type of tectono-diagenetic dolomite breccia) were retrieved from five locations in Lefkada Island, Greece. The mechanical properties of the intact, parent rocks were determined to define the degree of strength reduction due to the tectonic disturbance of the fault rocks. The mechanical properties of the fault rocks significantly vary, a fact that is attributed to their structural and textural properties. These properties were quantified using a novel image processing technique and two (2) discrete algorithms. The durability characteristics of the studied rocks were also assessed through freeze-thaw and slake durability tests. The specimens with a higher tectonic disturbance yielded increased degradation characteristics, in repeated freeze-thaw and slaking cycles proving that the behavior of the material can drastically change over time due to weathering and erosion processes.. The findings of this paper suggest that the behavior of fault rocks cannot be approximated by the existing rock mechanics principles and therefore, a more focused methodology to derive their mechanical properties is needed. [ABSTRACT FROM AUTHOR]

This paper presents results on the behavior, in terms of CO 2 capture capacity and attrition/fragmentation tendency, for six limestones processed in a dual interconnected fluidized beds system under operating conditions simulating those of sorption-enhanced gasification in presence of water vapor. Ten calcination/carbonation cycles have been carried out for each sorbent; in particular, carbonation has been carried out at two temperature levels (650 °C and 700 °C), with a CO 2 and H 2 O inlet concentration of 10% for both gases. Degree of CaO carbonation (with related modelling) along the cycles, and particle size distribution at the end of the cycles, have been analyzed and discussed, together with results coming from ex situ impact fragmentation tests carried out in a specifically devoted apparatus. The discussion has been extended to particular cases in which the system was operated in the absence of steam, to analyze the role of this species on the sorbent behavior. [Display omitted] • Steam upon carbonation influences CO 2 capture and attrition/fragmentation. • Temperature promotes kinetics, diffusion, but also sintering in presence of steam. • In absence of steam, carbonation temperature favours larger CO 2 capture. • If steam-induced sintering is enhanced, particles are mechanically more resistant. [ABSTRACT FROM AUTHOR]

[Display omitted] • Converting limestone sludge waste into hydroxyapatite rod-shaped particles by hydrothermal method. • The obtained materials were found to be effective adsorbents for Pb2+. • Preparing a novel sorbent with high adsorption capacity of 476.19 mg/g. • This provides a new avenue to address wastewater treatment and limestone sludge. This paper reports on the recycling of the Ca2+ ion-rich filtrate of limestone sludge for use as a raw material in the hydrothermal synthesis of hydroxyapatite (HAp) applicable to the removal of Pb2+ ions from aqueous solutions. Samples of HAp (eco-HAp) were prepared using a range of Ca/P molar ratios (Ca/P MRs) (1, 1.67, 2.33 and 3) and hydrothermal temperatures (393–453 K). Fourier transform infrared spectroscopy revealed the presence of O–H groups and PO 4 3–(ν1) groups (indicative of HAp). Transmission electron microscopy revealed the presence of elliptical surface microstructures. Solid-state nuclear magnetic resonance (NMR) spectroscopy revealed single crystal sites of inorganic phosphorus (31P) and hydroxyls (1H). The adsorption capacity of eco-HAp samples reached 476.19 mg/g within 20 min. The results of adsorption kinetics were characteristic of pseudo-second-order kinetics. Langmuir adsorption isotherms revealed that the Pb2+ adsorption capacity of ecoHAp was 277.77 mg/g, which can be attributed to a synergistic mechanism involving ion exchange, chemical precipitation, surface complexation, and dissolution/precipitation. Taken together, these results demonstrate the potential of eco-HAp as an adsorbent material with broad industrial applicability for the removal of heavy metals from aqueous solutions. [ABSTRACT FROM AUTHOR]

This paper developed a cost-effective and highly carbonatable industrial-grade γ-C 2 S binder sintered from limestone and sandstone, aiming to advance the industrialization of γ-C 2 S binder in construction fields. The carbonation behavior of the industrial-grade γ-C 2 S binder, including the evolution of carbonation kinetics, compressive strength, phase composition, and microstructure with carbonation duration was studied. Results showed that a temperature of 1400 °C and limestone-to-sandstone mass ratio of 2.1 can be regarded as the optimal sintering regime, which can secure a relatively complete self-pulverization of industrial-grade γ-C 2 S binder. The industrial-grade γ-C 2 S binder had a milder carbonation reaction, which can reduce the evaporation of water and lead to 48% greater compressive strength, compared to that sintered from analytically pure reagents. During carbonation, the proportion of γ-C 2 S phase significantly decreased, while the proportions of CaCO 3 and silica gel notably increased in the first 1 h, followed with a slight change in proportions of those phases with the carbonation further extending to 24 h. Similarly, the degree of carbonation rapidly increased to 36.3% in the first 1 h, followed with a slight increase to 43.7% at 24 h. The carbonation of industrial-grade γ-C 2 S, accompanied with the precipitation of CaCO 3 on γ-C 2 S phase surface and the bond of silica gel among CaCO 3 grains, contributed to the formation of nacre-bionic interlocking brick-mud microstructure. This led to the rapid enhancement of compressive strength with carbonation of industrial-grade γ-C 2 S. • Industrial-grade γ-C2S binder from limestone and sandstone was sintered. • Industrial-grade γ-C2S showed a greater compressive strength after carbonation. • Limestone-to-sandstone mass ratio of 2.1 sintered at 1400 °C was the optimal regime. • Nacre-bionic interlocking brick-mud microstructure was formed during carbonation. [ABSTRACT FROM AUTHOR]

This paper analyzes manufacture of a new eco-cement (reduced CO 2 footprint and LC3 clinker content) by replacing natural limestone with fine limestone concrete demolition waste (CDW H). The ternary cement's content was partially replaced by a binary pozzolanic admixture (10%, 20%, and 30% proportions; 1:1 by weight) composed of CDW H and commercial metakaolin (MK). Results show the ternary eco-cement meets current standards' chemical and physical requirements. The pozzolanic synergy of the additives —CDW H and MK— is comparable to silica fume, as reflected in the new mortars' intrinsic properties (capillary water absorption and electrical resistivity), microporosity, and physical and mechanical characteristics, achieving maximum performance at 20% replacement. Kinetically, in ternary eco-cements, the formation of monocarboaluminate and hemicarboaluminate phases, the non-conversion of ettringite to monosulfoaluminate, and the reduction of the Ca/Si ratio in CSH gels all benefit kinetically as the replacement content increases. Use of limestone concrete demolition waste in manufacture of LC3 eco-cements is a viable option. • Recycling of the fine fraction of limestone CDW for the manufacture of LC3 cements. • Analysis of the scientific and technical feasibility of ternary eco-cements. • Good synergy of the binary mixture CDW-MK. • New ways to recycle RCD. [ABSTRACT FROM AUTHOR]

Ultra-high-performance concrete (UHPC) made of limestone calcined clay cement (LC3) exhibits excellent mechanical properties as well as good environmental friendliness. This paper studied the improving effect of nano-SiO 2 on the mechanical properties and microstructure of LC3-UHPC. The experimental results show that the addition of nano-SiO 2 demonstrates obvious advantages. The mechanical properties of LC3-UHPC are enhanced, and the frictional bond performance between steel fiber and cementitious matrix is also improved. The fiber/matrix bond strength is increased. A constitutive model describing the single fiber pullout behavior is established, and the values of related parameters are suggested. Besides, nano-SiO 2 also refined the cementitious microstructure of UHPC and made the matrix denser. Based on the comprehensive analysis of mechanical properties and microstructural characteristics, the optimal content of LC3 and nano-SiO 2 were proposed. [Display omitted] • The performance of LC3-UHPC was improved by using nano-SiO 2. • The microstructure of UHPC using nano-SiO 2 was optimized. • The fiber/matrix bonding behavior of LC3-UHPC was improved. • Comprehensive evaluation of the influence of nano-SiO 2 was conducted. [ABSTRACT FROM AUTHOR]

The Mosasauridae underwent a major radiation early in the Late Cretaceous, with the subfamilies Plioplatecarpini and Tylosaurini appearing in the Turonian. Here we report an almost complete mosasaur skull assigned to the plioplatecarpine genus Yaguarasaurus. The specimen was discovered southwest of Vallecillo in the northeastern Mexico state of Nuevo Leon, about 80 km north of Monterrey, in a laminated limestone layer of the upper member of the Agua Nueva Formation (Upper Turonian - ?Lower Coniacian). The specimen is referred to as a new species, Y. regiomontanus. This is the first report of Yaguarasaurus from Mexico and the most complete of the Americas. At roughly 5 m in length, it is one of the earliest large mosasaurids. Along with Yaguarasaurus columbianus , Russellosaurus coheni , and an unnamed plioplatecarpine from Texas, it documents the rapid diversification and expansion of plioplatecarpines in the marine realm in the Turonian. • The Highlight of the paper is that is a new species of mosasaurus described for Mexico. [ABSTRACT FROM AUTHOR]