Granitic Material Research Articles

Three-dimensional mesoscopic investigation on the dynamic compressive behavior of coral sand concrete with reinforced granite coarse aggregate (GCA)

In the construction of island and reef engineering, coral concrete shows a good application prospect due to its abundant raw materials. However, the porous and fragile mechanical characteristics of coral reefs limit their use as coarse aggregate in the preparation of coral concrete materials. This study utilized hard and dense granite as the coarse aggregate and regarded coral sand concrete as a two-phase composite material consisting of spherical granite coarse aggregate (GCA) and coral mortar. It investigated the enhancement effect of granite on coral concrete from a microscopic perspective. Five 3D mesoscopic models with different GCA contents and randomly distributed aggregates were established to reveal the variation patterns and failure mechanisms of coral sand concrete under impact loading with GCA. The findings demonstrate that the K&C model can effectively simulate the dynamic compression behavior of coral mortar and granite materials. Under the action of a half-sine incident wave, the dynamic compressive strength of the samples increases with the increase in GCA, demonstrating that the addition of GCA can effectively enhance the impact resistance of coral sand concrete. As the content of GCA increases, the sensitivity of the samples to the loading wave amplitude also increases accordingly.

Newly identified uranyl vanadate mineral formation in the Thrace Basin, NW Türkiye: Insights into identification and origin of carnotite and tyuyamunite minerals

The Thrace Basin is located in the northwest of Türkiye, bounded by the Rhodope Zones to the west, the Strandja (Istranca, Strandzha) Massif to the North, and the İstanbul Zone to the east. The Stranja Massif’s basement is composed of the Tekedere Group, which includes Paleozoic gneisses and schists, as well as the Şeytandere Metagranite, consisting of altered and unaltered metagranites. Unaltered metagranites are characterized by large feldspar crystals and are typically white and pink in color, while altered metagranites are typically yellow color. The subject of this study Şeytandere metagranites which the uraninite mineral, for the first time, was identified in unaltered metagranite samples, while carnotite and tyuyamunite minerals were identified in altered meta-granite samples. The morphologies and elemental compositions of these minerals were identified by Scanning Electron Microscopy (SEM) and Energy Dispersive X-ray Spectroscopy (EDS). The SEM-EDS analyses revealed that the major elements of carnotite [K2(UO2)2(V2O8)(H2O)3] and tyuyamunite [Ca(UO2)2(V2O8)(H2O)8] are of K, U and V and Ca, U and V, respectively. In the investigated samples carnotite has a plate-like morphology, whereas tyuyamunite shows a fibrous apperance. This investigation shows that carnotite and tyuyamunite are epigentically formed from uranyl vanadate minerals in the Şeytandere metagranite. These minerals indicate uranium leaching from granitic materials and re-deposition as fine specks in open pores by circulating meteoric water. The leached uranyl ions, combined with vanadate ions, form carnotite and tyuyamunite under weathering conditions.

Differences and implications of strontium distribution coefficient on various granite compositional materials.

The distribution coefficient (Kd) of radionuclides is a crucial parameter in assessing the safety of high-level radioactive waste (HLW) geological repository. It is determined in the laboratory through batch and column experiments. However, differences in obtained Kd values from distinct experiments have not been thoroughly assessed and compared. This study evaluated strontium (Sr) sorption on different granite materials using static batch and dynamic experiments (column and core-flooding experiments). The results from batch sorption experiments showed higher Sr sorption on granite under acidic and strongly alkaline conditions, low solid-liquid ratios, and low ionic strength. In column experiments, a two-site sorption model was used to simulate Sr transport in crushed granite and mixed pure minerals. The sorption of Sr on crushed granite exhibited a higher affinity than that of mixed pure minerals. The dual-porosity transport model was employed to investigate Sr transport behavior in fractured granite in the core-flooding experiment. Kd obtained from batch sorption experiments are four to twenty times higher than those from column experiments, and two to three orders of magnitude higher than that from a core-flooding experiment. The results of this study provide valuable insights into safety assessment for the HLW geological repository.

Evolution of Crack Source Mechanisms in Laboratory Hydraulic Fracturing on Harcourt Granite

Hydraulic fracturing has gained escalating significance in recovering unconventional reservoirs. However, the failure mechanism and its evolution with progressive fluid injection are not fully understood for granitic materials. To investigate, triaxial hydraulic fracturing on Harcourt granite and acoustic emission (AE) monitoring was performed by the self-developed multi-physical rock testing platform (MRTP). Source mechanism analysis suggests that tensile cracks account for the majority (62%) of all cracks throughout the hydraulic fracturing process. Tensile cracks with large energy are induced mainly around the borehole bottom, but their average energy is smaller than shear cracks. The entire hydraulic fracturing process is divided into three stages by injection measurements. In Stage 1, AE events are recorded with low energy emissions but high signal-to-noise ratios, revealing the initiation of hydraulic fractures before peak injection pressure. Tensile cracks are more dominant (78%) than other stages. In Stage 2, the number and magnitude of AE events increase exponentially along the trace formed in Stage 1. In Stage 3, hydraulic fractures have the largest magnitude among all stages. Shear cracks are nearly the same proportion as Stage 2, but more shear cracks with large magnitudes are observed following the trace formed by tensile cracks. A dense population of shear cracks can be found at the borehole bottom, and their distribution follows the average slip plunge of individual shear cracks induced by the injection fluid.

Geochemistry of Mallampalli Group Phyllite from Pakhal Supergroup, Western Belt of Pakhal Basin in Pg Valley, Telangana: Implications for Provenance & Source Area Weathering

Phyllites from the Mallampalli group from the Pakhal Supergroup rocks of Pakhal Basin in PG Valley, Telangana,India was analyzed for their major and trace element geochemistry in order to constrain their provenance and source area weathering. The analyses of the phyllites generally define a single geochemical group by their major- and trace-element abundances. The metamorphosed sediments may be classified as immature by their high index of compositional variability values of mostly < 1. HREE are generally depleted whereas LREE are typically enriched relative to average Proterozoic upper crust. Such geochemical characteristics suggest that the source of the phyllites dominantly consisted of felsic rocks. Average Cr and Ni abundances and Cr/Ni ratios of average phyllites of the Mallampalli metasediments indicate that the source consisted of granitic material. Major element data, plotted in Al2O3 – (CaO+Na2O) – K2O ternary diagram indicate that the phyllites have not undergone significant post-depositional K metasomatism. Low to moderately high chemical weathering of the source terrane is indicated by pre metasomatized chemical index of alteration values of 60 – 86. The geochemical data further suggest that the sediments were deposited within a passive margin setting and mostly supplied by the adjacent basement granitoids.

Development of a simple and efficient two-step microwave-assisted digestion method for the determination of REEs, HFSEs and other elements in granite samples by ICP-OES

An efficient two-step microwave-assisted digestion for the determination of REEs, HFSEs and other elements in granite samples by ICP-OES.

Source identification of morainic materials in soils of the Three Lakes region (Switzerland) using the fingerprinting technique

In regions of mid- to high-latitudes, soil development patterns are intricately associated with the Quaternary glaciations, which have reworked sediments and deposited a layer of heterogeneous superficial moraines having both autochthonous and allochthonous components. While the allochtony of the morainic material in the Swiss Plateau is widely accepted, the specific proportion of various geologic origins of the soil parent material remains largely unexplored. Fingerprinting techniques have emerged as valuable tools for accurately estimating the origin of the parent material composition. They may unveil the distinct contributions of different rock types to the overall soil composition. In total, 166 sites were analysed for their geochemical composition and the relative contribution of several rock components to them, such as carbonate, sandstone and three groups of rock granite (incl. granite, granulite and gneiss), gabbro (incl. gabbro, Allalin-gabbro and diorite) and serpentinite (incl. serpentinite and eclogite). For each site, an optimal set of elements (between 11 and 17) was selected. Thereby, a three-step statistical selection process was employed that included the range tests, the Kruskal-Wallis tests and a discrimination function. We identified eight key elements – Al, Ca, P, Fe, Mn, Sb, La, and Sm – which consistently appeared across all sites during the selection process. The geochemical composition of the soils of the Three Lakes Region was mainly determined by a mixture between granitic material (53.6%) and sandstone (21.6%) with a smaller contribution of serpentinite, gabbroic and carbonate material. The findings highlight that the FingerPro model can effectively identify the sources of geochemical composition in soils. One major difficulty in such calculations was, however, that sandstones had a relatively variable composition owing to their different origins.

Effective removal of arsenic from contaminated groundwater using an iron-based metal-organic framework

This study investigates the potential of an iron-based metal–organic framework (MOF) material, Fe-benzene-1,3,5-tricarboxylate (Fe-BTC), for arsenic removal from water. We conducted batch and column experiments to evaluate the effects of varying mass dosages of MOF and pH ranges on arsenic adsorption. Our batch experiments revealed that increasing the mass of Fe-BTC MOF led to higher adsorption capacity. Furthermore, within the range of pH values analyzed, Fe-BTC demonstrated stable arsenic adsorption capacity, suggesting that pH conditions did not significantly affect its performance. In the column experiments, we used granitic material amended with compost and compared arsenic concentration breakthrough curves with and without the presence of MOF to assess its efficiency in arsenic removal. Without MOF, we observed rapid arsenic arrival followed by a slow increase in concentration, indicating anomalous transport dynamics induced by the compost. The addition of MOF resulted in prolonged arsenic arrival and a stabilized lower concentration, indicating effective arsenic adsorption. Fe-BTC MOF exhibited a six-fold increase in arsenic adsorption compared to its absence when added to the soil material. We employed a fractional order advection–dispersion equation model to characterize and predict the physical and chemical dynamics in the column experiments. The transport model accurately matched the arsenic breakthrough curves in the column experiments by capturing the non-Fickian transport and sorption chemical dynamics. The model indicated that compost had an insignificant impact on arsenic adsorption due to flow heterogeneity, while higher dosages of MOF resulted in increased arsenic adsorption and non-Fickian dynamics.

Insight into immobilization mechanism of nuclear waste management by granite: Impact of waste chemical species

Nuclear waste immobilization is one of the ways to alleviate the harm of radioactive waste produced in the nuclear field to human beings and the environment. In the current study, granite was utilized as a substrate material for the immobilization of simulated radioactive waste. Based on the obtained results, the relationship between the waste chemical species and the physicochemical properties, such as solid-solubility of waste, infrared, density and leaching data, was systematically studied as well. The findings indicate that the granite substrate used for the immobilization of the simulated waste (Nd2O3) exhibits a solid-solubility limit of 27 wt%. When the added content of waste is below 27 wt%, all Nd elements are immobilized into the glassy phase. However, when the waste content exceeds 27 wt%, in addition to being immobilized in the glassy phase, the presence of Nd2O3 reacted with Ca3Si3O9 to form Ca2Nd8(SiO4)6O2. As the Nd2O3 content increased from 20 wt% to 25 wt%, the microstructures related to Si-, Al-, and Fe-are more involved in the immobilization of waste. However, the appearance of Ca2Nd8(SiO4)6O2 and Nd2O3 makes the density and Vickers hardness of the matrix not increase further. The maximum density and hardness values are 3.17 g cm−3 and 7.88 GPa, respectively. The leaching results show that the cured body has good anti-leaching performance (LRNd = ∼10−6 g cm−2 d−1). Finally, the comparison of vacancy formation energy of Nd in Nd2O3 and Ca2Nd8(SiO4)6O2 proved that the formation of Ca2Nd8(SiO4)6O2 is beneficial to the immobilization of simulated waste. This study provides a certain reference for the selection of nuclear waste solidification substrates. This kind of granite material from nature has the potential advantages of low cost and better immobilization effect on waste, and may be more suitable for the treatment of radioactive waste in the future.

Structural behavior of the deep hole internal grinding machine structure with artificial granite material

Structural behavior of the deep hole internal grinding machine structure with artificial granite material

LATE-OROGENIC GRANITOIDS OF THE TERVU AGMATITIC ZONE IN THE SOUTHEASTERN PART OF THE SVECOFENNIAN BELT (THE NORTHERN LADOGA AREA, RUSSIA)

The formation of breccia zones was taking place with the simultaneous healing of them by granitic materials at the final stages of the Late Proterozoic magmatic and metamorphic activity in the region 1.86 Ga ago. The Tervu breccia zone with granitic agmatites has a sublatitude orientation, which is discordant in relation to the early structures and Kurkieki enderbite and Lauvatsari-Impiniemi diorite-tonalite complexes in the Svecofennian rocks of the Ladoga region. There are the largest granitic bodies in this area – Tervu and Peltola intrusions located in the Tervu breccia zone. The U–Pb age of monazite from granites of the Peltola intrusion is determined as 1859 ± 4 Ma, and coincides with the age of the granites of the Tervu intrusion (1859 ± 3 Ma). This assumes that the granites of both intrusions and some surrounded smaller bodies were intruded simultaneously into the tectonically weakened space when plastic deformations turned to elastic-plasticity ones during at the late-orogenic stage. The results obtained reveal the features of the tectonic development of the joint zone of the two largest blocks of the Fennoscandinavian shield – the Karelian craton and the Svecofennian belt.

Late Orogenic Granitoids of the Tervu Agmatitic Zone in the Southeastern Part of the Svecofennian Belt (Northern Ladoga Area, Russia)

The Tervu breccia zone was formed at the final stages of the Late Proterozoic magmatic and metamorphic activity (1.86 Ga ago) and healed with granitic material shortly after its formation. The Tervu breccia zone with granitic agmatites has a sublatitudinal orientation, which is discordant in relation to the earlier structures and Kurkijoki enderbite and Lauvatsaar–Impiniem diorite–tonalite complexes in the Svecofennian rocks of the Ladoga region. The largest granitic bodies in this area, the Tervu and Peltola intrusions, are located in the Tervu Zone. The U–Pb age of monazite from granites of the Peltola intrusion is determined as 1859 ± 4 Ma and coincides with the age of the granites of the Tervu intrusion (1859 ± 3 Ma), which indicates that the granites of both intrusions and some surrounding smaller bodies were intruded simultaneously into the tectonically weakened space at the late-orogenic stage while plastic deformations were turning to elasto-plastic ones. The results obtained reveal the features of the tectonic development of the junction zone of the two largest blocks of the Fennoscandinavian shield, the Karelian Craton and the Svecofennian Belt.

Experimental Investigation of Mechanical and Fracture Behavior of Parallel Double Flawed Granite Material under Impact with Digital Image Correlation

During the excavation of underground projects, the rock masses left as the bearing support system are also subjected to dynamic loads from the excavation activities ahead. These rock masses have been damaged and fractured during the initial exposure (dynamic loads) and are subjected to static loads in the subsequent process as the support system. In this study, granite rock samples and specimens with different angles were produced, preloaded with different confining pressure, and under a combination of dynamic and static loading tests using a modified dynamic and static loading system: split Hopkinson pressure bar (SHPB). The peak strain and dynamic modulus of elasticity are weakened by the inclination angle in a similar way to the strength, with the specimens showing an evolutionary pattern from tensile strain to shear damage. The change in the inclination angle of flaws would weaken the dynamic and combined strengths, and a larger inclination flaw results in a significant decrease in its strength. Fractal analysis revealed that the fractural dimension was closely related to the fissure angle and showed a good linear correlation with the strain rate. This study will provide an important security assurance for deep mining.

Study on dynamic mechanical properties and constitutive model of granite under constant strain rate loading

A systemic understanding of the dynamic mechanical properties and dynamic constitutive model of granite is of great significance to the study of natural disaster prevention and protection of granite buildings. In the present study, constant strain rate loading tests of granite specimens under different impact velocities were carried out by using a shop-fabricated cylindrical conical striker and split Hopkinson pressure bar (SHPB) test system. The compressive strength of granite material increases with the strain rate, and therefore, a continuously smooth uniaxial dynamic strength criterion suitable for describing the changes in the dynamic increase factor (DIF) with strain rate was proposed and tested. The granite specimen under impact loading was intact when the strain rate was lower than 80 s−1, cracked when it was 80 to 90 s−1, fractured when it was 90 to 135 s−1, and crushed when it was over 135 s−1. Ultrasonic wave tests were performed to evaluate the damage caused by impact, and the quantitative relationship between the damage value and peak stress was established based on regression analysis. The results showed that the stress threshold causing damage was 50.15 MPa with a corresponding strain rate of 31.7 s−1 and a peak strain of 3670 microstrain. A new constitutive model describing the dynamic mechanical properties of granite was developed based on a nonlinear viscoelastic model (the ZWT model), and the constitutive parameters were then determined. A user-defined material subroutine named VUMAT of ABAQUS finite element software was applied to describe the established constitutive model and simulate the impact process of granite. The results confirmed that the developed constitutive model can well describe the prepeak dynamic mechanical properties of granite under impact compression.

Coupled thermal-hydraulic simulations of fracturing in granite under high temperature and high pressure treatment via peridynamic

This paper described an improved multi-layer computational method based on fully coupled thermal-mechanical ordinary state-based peridynamics (OSB-PD), which enables simulating fracturing in granite under coupled thermal-hydraulic effects. Four computational layers, i.e., pre-treatment thermal layer (PTL), mechanical loading layer (MLL), interactive thermal layer (ITL), and hydraulic mechanical layer (HML) were included in this method. PTL was used to simulate the heterogeneity of granite materials by creating initial pre-existing microcracks. MLL was utilized to apply borehole pressure, while ITL was designed to generate real-time thermal forces. HML was employed to apply equivalent hydraulic pressure to cracks, and distinguish between thermal-induced and hydraulic-induced damage. Two verification cases, including hydraulic fracturing and sleeve fracturing of granite specimens at different pressurization rates, as well as the steady-state heat conduction of a hollow cylindrical specimen, were simulated to investigate the convergence, capability and accuracy of the numerical method. The proposed method was then applied to the hydraulic fracturing of granite under high temperature and high pressure (HTHP) treatment. The complex interactions among natural pre-existing microcracks, thermal-induced microcracks and hydraulic-induced cracks was properly predicted. The effect of cold water (temperature gradient) on the fracture morphology and breakdown pressure of granite specimens was also discussed. A systematic comparison with the experimental results shed lights to the failure mechanisms of granite specimens subjected to HTHP hydraulic fracturing tests.

Thermal effects on fracture toughness of cracked straight-through Brazilian disk green sandstone and granite

Cracked straight-through Brazilian disc (CSTBD) samples prepared using two rock materials were used for thermal treatment from room temperature to 700 °C. Uniaxial splitting experiments were performed using an automatic electro-hydraulic servo press to study the evolution laws of physical and fracture properties of different deep rock materials under high-temperature geological conditions. The fracture characteristics were measured using an industrial camera and digital image correlation technology to analyze the effect of high temperature on fracture properties and failure modes of the CSTBD samples after different thermal treatments. The micro-damage properties of green sandstone and granite materials were obtained using a scanning electron microscope (SEM). The following conclusions were drawn from the test results: (1) With the increasing temperature, the fracture characteristics of green sandstone and granite change from brittle fracture to plasticity fracture, the longitudinal wave velocity of granite decreases sharply at 600 °C, and the damage factor reaches 0.8748 at 700 °C. (2) The fracture toughness of green sandstone and granite decreases with increasing temperature; however, the decreasing range of granite is larger than that of green sandstone. (3) As the temperature increases, the fracture morphologies of green sandstone and granite materials become rougher, whereas thermal damage cracks of granite and intergranular fractures inside sandstone as well as pores of sandstone increase. (4) The crack tip opening displacement and peak strain corresponding to peak load increase with the temperature. • The effect of thermal treatment on the fracture characteristics of granite and green sandstone materials was studied. • The evolution law of fracture toughness of rock with temperature was studied. • The fracture morphology of granite and green sandstone after thermal treatment was analyzed using SEM. • The CTOD and strain field curves of CSTBD specimens after thermal treatment were calculated using DIC technology.

An Experimental Behavior on Green Concrete utilizing Granite Slurry Waste (GSW) as Partial Substitute of Cement

Granite Granite materials are widely used by the construction industries. Granite slurry waste is a fine powder similar to cement that is causing climate and environmental problems around the world today. Individuals’ respiratory and sensitivity issues are exacerbated by the disposal of this granite waste. Concrete seems to be the most versatile building material. The usage of GSW in concrete could help alleviate a variety of issues, including CO2 emissions in the environment. Various molds were formed in this study to investigate the durability properties of concrete (water permeability, abrasion resistance, UPV test, and modulus of elasticity (static) for green concrete to be w/c 0.4 and 0.5. More workable green concrete is obtained at the varied replacement of granite slurry waste. The result has been shown to increase the depth of water penetration and modulus of elasticity with the addition of GSW for two w/c 0.5 and 0.4. The maximum water penetration depth was reported to be 85 mm at a 30% substitution level of GSW. The abrasion loss was step by step increased with an increasing of different substitution ranges (5% to 30%) of GSW as a partial substitute of cement (OPC and PPC). The highest abrasion loss was likewise observed to be less than 1 mm. The modulus of elasticity (Static) of concrete was increase at the substitute range of 5%. The UPV test results showed that the quality of GSW concrete is good. These studies show that the inclusion of granite slurry waste in green concrete will show that it will be cheap, protect the resources, and be more sustainable.

The Adsorptive and Photocatalytic Performance of Granite and Basalt Waste in the Discoloration of Basic Dye

The present work explored the adsorptive capacity and catalytic activity of rock powders from basaltic and granitic rocks in the discoloration of synthetic and industrial effluents containing the yellow dye Basic Yellow 96. The rock powders were characterized with scanning electron microscopy associated with energy-dispersive spectroscopy, photoacoustic spectroscopy, N2 physisorption and X-ray diffraction, the latter confirming the abundant presence of silica in the four materials studied. The basaltic powders presented specific surface areas between 7 and 10 times greater than those of granitic materials, which allowed up to 92% removal of the dye in 3 h of test using the basaltic powder. Despite the smaller area, the granitic materials showed considerable photocatalytic activity in 3 h, 94%, the same as that of the basaltic materials in the photocatalysis. Granitic and basaltic photocatalysts proved to be efficient in the discoloration of synthetic and industrial effluents, although TOC analyses indicated that it was not possible to promote the pollutant mineralization in the industrial effluent. Both artificial light and sunlight were effective in the photocatalysis of the dye, although the former was slightly faster.

Laboratory investigation on engineering mechanics properties of granite after various heating/cooling treatments.

The purpose of this study is to investigate the engineering mechanical properties of granite after various heating/cooling treatments through laboratory investigation. Granite specimens were heated at different temperatures (25, 200, 400, 500, 600, and 800 °C) and cooled by two methods (natural cooling and water cooling) to investigate the change patterns of engineering mechanical properties of granite materials after heating/cooling treatments, including surface hardness, uniaxial compressive strength, modulus of elasticity, peak strain, and point load strength. The damage mechanisms of granite under different heating/cooling treatments were also revealed. Finally, the correlation between uniaxial compressive strength, point load strength, and surface hardness were analyzed by linear and nonlinear fitting methods. The results showed that the strength index of granite can be well evaluated by the hardness index, which has important engineering significance.

Characteristics of cerium doped aluminosilicate glass as simulated radioactive waste forms: Effect on structures and properties

Various cerium doped aluminosilicate glass was prepared by a high-temperature melting method using natural granite material as the only origin of the glass substrate. TG-DSC was used to understand the changes of this aluminosilicate material in the melting process. The structure of the glass was systematically studied by X-ray diffraction, scanning electron microscopy, infrared spectroscopy, X-ray photoelectron spectra. This type of aluminosilicate material begins to vitrify at about 1000 °C, and its maximum vitrification degree was obtained at 1500 °C. The structure of the glassy waste forms prepared at this temperature is mainly composed of Q3 and Q4 structural units. With the addition of cerium ions, the proportion can even reach 82%. Such good glass integrity makes this type of aluminosilicate glass density and hardness up to 2.89 g cm−3 and 7.80 GPa, respectively. However, the addition of excessive cerium ions destroys the integrity of the network, resulting in that the glass can only carry 17 wt% cerium ions at most. At this point, 55.93% of Ce4+ ions are reduced to Ce3+. In the meantime, cerium ions are evenly distributed in the glass network. This study provides a strategy for the treatment of radioactive waste with similar properties with cerium ions.