Rock Quarry Research Articles

Strength studies on Geopolymer Concrete produced by Recycled Coarse Aggregate and Quarry Stone Dust as Fine Aggregate

Geopolymer concrete is one of the trending techniques adopted to replace the conventional binder by any alumino-silicate material like fly ash or GGBFS. Approximately Geoploymer concrete are as productive as conventional concrete. But the key pro of Geopolymer concrete utility is to recycle concrete waste and demolition waste are transformed into coarse aggregate, which reflects in the environment and economic benefits. The natural fine aggregate (NFA) is replaced by the residue quarry fines obtained from the crushed quarry rock often termed Quarry dust or Quarry stone dust (QSD) by proportions 0%, 20%, 40%, 60%, 80%, and 100%. In this research study, fly ash is utilized as the binding material activated by the di-solution of NaOH and Na2SiO3 collectively to initiate a chemical reaction to attain productive strength. From the overview of previous papers literature, the geopolymer concrete is not having any proper mix design procedures, Therefore the trial and error method adopted. This research is conducted to study over results of the practical approach on geopolymer concrete composed with 40% of recycled coarse aggregate (RCA) in place of Natural coarse aggregate and varying different percentages of QSD in the place of Natural fine aggregate.

Comparison of the existing and calculated blast design parameters for the rock mass conditions at Bamesso-Latet rock quarry

Blasting is the most cost effective methodology to break rock for mining engineering applications. A good production blast will break only the rock that is needed to be removed, leaving the host rock with minimal damage. Accurate measurement of blast, fragmentation is important in mining and quarrying operations, in monitoring and optimizing their design. Currently, there are several methods available to predict damage due to blasting. The accuracy of many of these methods is questionable, and in most cases, the methodologies over predict the results. This paper presents a practical method (i.e. Langefors’s method) that we shall use in Bamesso-Latet rock quarry to do a comparison between the existing and calculated blast design parameters. The proposed method allows to assess the rock damage from blasting. It shows great potential as a practical aid to control and get a good quality of the fragmented material in Bamesso-Latet rock quarry.

Modelling of thermo-mechanical effects in a rock quarry wall induced by near-surface temperature fluctuations

Mechanical response of rock masses to the periodical fluctuation of surface temperatures is a relevant topic to be focused on for the comprehension of short- to long-term stability of rock slopes continuously stressed by slight yet periodical actions. To better understand how preparatory factors can lead rock masses toward failure, thermal and strain monitoring activities are ongoing in a selected quarry wall, where an experimental test-site was implemented on a jointed rock block. The role of pervasive joints in perturbing the heating-cooling process of the rock mass and their related effects was already output by direct and remote monitoring. For these purposes, FDM numerical modelling was focused on the comprehension and simulation of induced mechanical effects due to cyclical thermal forcings over a simplified 2D half-space. Therefore, the role of rock mass joints on both heat propagation and resulting thermo-mechanical effects was analysed, basing on monitoring data, field experiments and numerical modelling. Numerical results output the role of periodic daily, annual and compound thermal input in inducing irreversible deformation along joints under different rock mass jointing configuration, as a function of the intrinsic period of thermal input and joint attitude. Temperature distribution across joints was also analysed as a possible constraining effect for time and space distribution of yielding. A sensitivity analysis of heat propagation conditions was performed in order to infer the role of joint sets on induced thermo-mechanical strains at the rock block scale. A non-negligible influence on surficial as well as deeper portions of the rock mass was observed, highlighting how near-surface temperature fluctuations can drive the long-term evolution of rock block conditions towards failure.

Slake Durability Index of the Stone Aggregate Used in the Morelia Michoacán Region

The study of durability is very important because buildings are expected to last; since durability is attributed to the materials used in construction, the study of such materials is required. Among them, stones play a fundamental role as part of the structures, as well as stone aggregates in the elaboration of asphalt blends and concrete blends. Bearing this facts in mind, quarry stones of volcanic and crushed materials were studied in the mexican state of Michoacán.In this work, the Id2, density, and absorption data were correlated to obtain a mathematical model that helps predict Id2 and verify the relationship between the variables. On the other hand, logistic regression was used to classify rock quarries according to their durability index.

Evaluating Optimum Strength of Geopolymer Concrete using Quarry Rock Dust with Inclusion of Natural and Hybrid Fibers Under Ambient Curing

Conventionally used cement –a primary binder also a necessitate element in producing concrete rates first in the construction industry. Production of conventional cement requires a greater skill and is energy intensive. The usage of waste materials in the production of concrete and reduction in cement content was only the possible alternative in the past decade. Associated risks with the production of Ordinary Portland Cement are well known. A greener aided with a natural friendly claim can be made only with the usage of the waste materials and reduction in evolving respiration gas to the atmosphere. Almost all works are carried out using source material fly ash, with fine aggregate and coarse aggregate. Concrete plays a vital role in the construction industry and on the other hand, river sand; one of the essential material has become very expensive which is a scarce material. Depletion of sand is a hectic issue due to increased usage of sand in construction. No other replacement materials such as quarry rock dust is not concentrated in casting geopolymer specimens. Even though in some research papers the replacement materials are added only in partial replacement without aiming on 100% replacement. Many researches mainly focus towards test results of GPC specimens using steel fibers, glass fibers. But the study related to natural fibers and hybrid fibers are found scarce. The main part of this work aimed at characterizing the engineering strength properties of geopolymer concrete by 100% replacement of fine aggregate with quarry rock dust. Hence, combination of flyash and quarry rock dust in GPC have been considered for evaluating the mechanical properties of geopolymer concrete. Also, investigation focuses on incorporation of three different fibers namely polypropylene fibers(PF), coir fibers(CF) and hybrid fibers(HF) in different percentage of proportions such as 0.5%,1%,and 1.5% to determine the maximum strength properties of GPC.

Assessment of the spectral component of seismic vibrations of protected objects during explosions in rock quarries

The article was awarded to the honored practitioner of the URSR graduate School, the laureate of the State Prize of Ukraine, professor Vynoslavskiy Vasiliy Mikolayovich, a stretch of 27 years dean of the faculty of mining of the Kiev Polytechnic Institute. 14 September 2020 year 100 years from the day of the birth of him. The article briefly describes his life path and achievements, his life position and scientific achievements. Purpose. The purpose of this article is to study the dissipation and energy distribution of explosive pulses as they pass through the rock massif and the foundation of protected objects, as well as to study the amplitude and energy of seismic oscillations of protected objects under the action of an explosive pulse. Methodology. To study the dissipation and energy distribution of explosive pulses and the interpretation of the results in this article used the methods of spectral analysis (study of autocovariance functions, joint covariance functions, energy autospectras and cross-spectral analysis).Findings. The amplitude of seismic oscillations of the output pulse (foundation surface) for the system "soil - foundation" is 7.35 times lower than the amplitude of soil oscillations at a distance of 70 m from the experimental object, the energy decreased by 8.23 times. This indicates that the foundation of the research object absorbed about 88% of the seismic energy that approached it. The frequency range 5-9 Hz is resonant. In this range, the oscillation frequency of the object foundation is close to the oscillation frequency of the input pulse, which leads to an increase in the energy and amplitude of seismic oscillations and the formation of microcracks in the foundation. For the system "foundation - the top of the tower" the amplitude and energy of oscillations at the top of the tower is 2 times greater than on the surface of the foundation. This fact indicates that due to the significant height of the towers (42.6 m), there is a rocking under the action of an explosive impulse. The maximum amplitude of oscillations of the top of the tower and the surface of the foundation is observed at a frequency of 5 Hz. This indicates that the foundation and towers respond to the explosive impulse as a single object. The nature and form of phase-amplitude characteristics of mutual spectra (hodographs) indicate that the experimental system "source of the explosion-soil massif-foundation-tower for cement storage" is unstable and part of the energy is spent on the formation of microcracks. Originality. The method of research of the characteristics of the rock massif and protected objects used in the article indicates the possibility of a more detailed study of the mechanism of development of microcracks and their transition to unstable destruction. Practical implications. The practical value of the results lies in the information obtained to protect research objects from the negative and destructive effects of seismic pulses, as well as the ability to influence the flow and energy dissipation of explosive pulses by changing the parameters of the explosion or other engineering solutions.

Ultrasonic rock microcracking characterization and classification using Hilbert–Huang transform

This study aims to set up a non-destructive method to control the quality of aggregates using ultrasonic wave acquisition and processing. Two applications are presented proving the applicability of the proposed methodology. The first is the characterization and classification of four limestone rocks from cement quarries in the northern part of Tunisia selected from different geological ages (Lower Jurassic, Upper Cretaceous, and Lower Eocene). The second application deals with assessing rock crushing-induced microcracking evolution in quarried rock from the first initial source rock mass to the final aggregate. Five stages were considered: before the blast (bench front), after the blast round (muck pile), after the primary crusher, after the secondary crusher, and after the tertiary crusher. A physico-chemical and ultrasonic characterization was performed on aggregates and core samples in order to identify their characteristics namely the crack porosity and P-wave velocity. A cluster statistical analysis was then adopted to classify the investigated samples into several groups where crack porosity is the most relevant factor in classifying their quality. In addition to measuring ultrasonic parameters such as the spatial attenuation and P-wave velocity, the ultrasonic study looks at the spectrum of the received signal (non-stationary and nonlinear signal) by measuring the instantaneous energy density with the Hilbert–Huang transform. Beyond the fact that the high negative correlation between the P-wave velocity and the instantaneous energy was identified, the methodology developed allowed to prove that the latter is a relevant factor for the classification of limestone rocks.

Building damage due to vibration from rock blasting

Construction activities such as blasting, piling, compaction, excavations, and construction traffic can produce vibrations of sufficient strength to cause damage to neighbouring buildings and structures. Therefore, many countries have national limit values for construction vibration in standards. However, building damages assumed to originate from vibrations are seldom observed. This may indicate that today's limit values are unnecessarily strict. In this field little newer research has been undertaken to scientifically observe the onset of cracking, and there is a particular lack of information about which role the frequency content of the vibration plays. In this study the onset of blast induced cracking was observed in two instrumented test structures located in a rock quarry. Two buildings were constructed, one in cast-in-place concrete without reinforcement and one made of lightweight construction blocks in expanded clay aggregate (LECA). The buildings were instrumented with geophones and Fiber Bragg Grating Sensors (strain sensors). In addition, vibrations on the ground surface and air blast overpressure were measured. Test blasts were designed to produce increasing vibration values, starting with peak particle velocities (PPVs) around 20 mm/s and ending with PPVs above 250 mm/s. No visible cracks were found on any of the two buildings. However, the last blast, which produced PPVs above 260 mm/s, resulted in a residual displacement of 0.05 mm across the 110 mm strain gage length above the door of the concrete building. The results of the test indicate that the limit values of most national standards include a large safety margin for buildings founded on rock. Further, the dominant frequency was determined by different methods and the results show a considerable deviation, with a distinct difference between methods which determine the frequency in a short time interval around the highest peak and methods which are using the entire vibration time series. In addition, methods which determines the frequency in short time intervals show a large spread in the frequency between the different vibration cycles.

Environmental impact assessment (EIA) of hard rock quarrying in a tropical river basin-study from the SW India.

The increase in demand of building stones and construction-grade sand has resulted in aggressive hard rock quarrying in many parts of the world. The problems are to be evaluated in detail for the judicious use of resources on the one hand and ensuring health of the ecosystems on the other. The present study aims to evaluate the impact of hard rock quarrying on one of the important twin- river basins in SW India, the Netravati-Gurpur river basin, which hosts the fast developing urban centre, the Mangalore city. A total of 64 hard rock quarries are located in the basin which together extracts about 6.75millionty-1 of rocks/rock products for different purposes. An assessment of the impacts of quarrying using the rapid impact assessment matrix (RIAM) reveals marginal, short-term positive impacts in economic-operational components but major negative impacts on all the other environmental components. The study indicates that the present intensity of quarrying is unsustainable with a sustainability index of - 0.25. Therefore, hard rock quarrying in the study area is to be strictly regulated for bringing down the river basin degradation to the barest minimum level and maximizing the ecosystem benefits to its full potential.

Environmental impact of quarrying of building stones and laterite blocks: a comparative study of two river basins in Southern Western Ghats, India

Mining and quarrying for minor minerals impart significant economic, environmental and social impacts in and around the affected areas. The problem is severe in the small river catchments as the effective area available for assimilating negative impacts of the activity is minimal, compared to large river basins. To address these issues, an investigation has been carried out in two river basins of southern Western Ghats (India)—the Netravati–Gurpur and Periyar–Chalakudy river basins. Both these basins host two important port cities of south India—Kochi and Mangalore. The study reveals that about 6.75 × 106 ty−1 of hard rocks are being extracted in the Netravati–Gurpur basin through 64 quarries. At the same time, the total number of quarries and extracted amounts in the Periyar–Chalakudy river basin are 525 and 10.47 × 106 ty−1, respectively. Many hillocks in the region are turned to a cluster of ugly scars, degrading the ecology and aesthetics of the area. Lowering of water table, modification or disappearance of natural drainages and environmental pollution are some of the other observations noticed in the area. The environmental impacts of laterite quarrying are comparatively less than that of rock quarrying as removal of the hard laterite cap rock enhances water percolation and makes the area more irrigable for agriculture. The study stresses the need for environment-friendly quarrying alternatives with stringent guidelines to improve the overall environmental quality of the area on one hand and to meet the developmental requirements on the other.

Hydrochemical characterization of abandoned quarry and mine water for domestic and irrigation uses in Abakaliki, southeast Nigeria

The Abakaliki area has been renowned for lead–zinc mining and hard rock quarrying, and these activities generate acid mine drainages (AMDs) and chemical dissolution of minerals into the water, respectively. This research is aimed at assessing the influence of AMDs and other dissolved elements on water quality for domestic and irrigation uses in the area. Thirty-five water samples were collected and analyzed for physicochemical parameters, including: pH, total dissolved solid, electrical conductivity, major cation and anion and heavy metals using atomic absorption spectrophotometric methods. Mathematical calculations were used to deduce irrigation parameters. Result indicates that pH of water samples is slightly basic to acidic, and EC ranges from 5.28 to 1492 µS/cm. Only samples around Nigercem, Nkalagu and lead–zinc mines at Enyigba were above WHO permissible limit for drinking water. The concentrations of Na+, K+, Ca2+, Mg2+ and HCO3− were within WHO set standard for drinking water, while Cl− and SO42− were above the WHO set standard. Irrigation parameters showed soluble sodium percentage between 8.33 and 100.00, sodium percentage ranges between 2.77 and 300.00%, Kelly ratio ranges from 0.03 to 3.00, magnesium absorption ratio ranges between 16. 92 and 123.5, total hardness ranges between 3.00 and 125.0, residual sodium bicarbonate ranges between − 23.84 and 0.11, and potential salinity ranges from 2.93 to 14.77 within the study area. Abandoned mine water in the area is fairly suitable for irrigation uses, but unsuitable for domestic uses. This is due to high chemical activities taking place in the mine ponds, and these 17 ponds have been abandoned for over 2 decades. Deductions from Soltan classification revealed that 98% of groundwater falls within deep meteoric water.

RICERCHE STORICO-ARCHEOLOGICHE DELL’UNIVERSITÀ CATTOLICA DI MILANO SUL DELTA DELL’INDO (2010-2018)

RICERCHE STORICO-ARCHEOLOGICHE DELL’UNIVERSITÀ CATTOLICA DI MILANO SUL DELTA DELL’INDO (2010-2018)

Angle impact on drill life during hole drilling land mine explosion at Quangninh area, Vietnam

Rock drilling and blasting holes created during construction of underground mining in general and in Quangninh are the interaction of the drill into the rock. Drilling efficiency and productivity depend on many parameters such as power dam, the rock solidity and the rotational speed of drilling and geometric parameters of the drill head. These parameters determine and affect the durability of the drill head. In this report, the authors present the results of experimental studies of the influence of sharp angles on the durability of the cross drill head during the drilling process and blasting rock in the Quangninh coal region. According to the results, it is established that the wear intensity f varies positively with firmness i h and inversely with the sharp angle of the drill head in the range of studied sharp angles. Nevertheless, the variation of wear intensity with regard to the change in sharp angles is not significant compared to the variation of wear intensity according to the rock strength. Research results can be used to calculate, design and choose appropriate drill rock quarry that increases the productivity and efficiency of drilling, contributing to reducing product costs.

Transmission and Reflection Characteristics of Perforated Submerged Single and Multiple Artificial Reef Units

Abstract Submerged breakwaters formed by natural rocks dissipate the incident wave energy. Continuous quarrying of rocks has resulted in its depletion, leading researchers to look for alternate materials for the formation of such barriers. Thus, the concept of artificial reef units has evolved which has been gaining importance owing to the flexibility in molding to any desired shapes and sizes, workability and also due to the fact that it creates a habitable environment to marine flora and fauna. From the hydrodynamic performance perspective, artificial reef units are proven to be more efficient in reducing wave transmission on the lee side (e.g., Southern Caribbean shore of Dominican Republic and Vaan Island, Tuticorin, India). A comprehensive experimental investigation to examine the effect of trench width on hydrodynamic characteristics of the submerged reef system was carried out. The trench width was varied by incorporating single, double, and multiple perforated submerged trapezoidal artificial reef units. The focus of the present study is mainly on the influence of the number of reef units, relative crest width, and relative trench width of the submerged reef system on its transmission and reflection characteristics. The relative trench width was found to be an influential factor on wave transmission past the structure, and the least wave transmission was achieved for the reef configuration with eight units. The details of the experimental investigation, results and discussion are reported in this paper.

Naturally Occurring Asbestos in France: A Technical and Regulatory Review

ABSTRACT Naturally occurring asbestos (NOA) has been a well-known issue within rock quarries for a long time. In France, the subject has recently become more controversial, particularly since 2013. In fact, some mineral fibers with the chemical composition of regulated asbestos (i.e., actinolite) have been discovered in road-base aggregates and associated air filter samples. The main problem concerns the determination of the asbestiform versus non-asbestiform character of such mineral particles. The in-force standard based on the morphological identification of a fiber does not allow one to make this distinction. Presently, in France, the asbestos analysis of building material is based on a “yes” or “no” result. This method has limitations for analyzing NOA, as NOA may be present in lower concentrations in natural materials, especially in road-base aggregates. The health effects of the non-asbestiform particles, also called “cleavage fragments,” with fiber morphology are not well established. The French government mandated the National Agency for Food, Environmental and Occupational Health and Safety to conduct a review on the “state of the art” concerning the cleavage fragment issue. The conclusions of the report highlight the fact that elongate mineral particles (EMPs) are up for debate and address remaining questions concerning this subject. The next fundamental step is to secure agreement on the terminology of EMPs with the aim of comparing the studies in different disciplines.

The Dozdaqi Area; Establishment of Bronze Age in the North of Urmia Lake

The Dozdaqi Area; Establishment of Bronze Age in the North of Urmia Lake

Assessment on Workability and Strength Properties of SCC using Quarry Rock Dust and different bases of Super Plasticizers & VMA

SCC is a concrete which has the ability to flow like liquid. This flowability of concrete is achieved by limiting the size of coarse aggregate content. Also 20% of the coarse aggregate is replaced by utilizing flyash inorder to increase the percentage of powder content..And due to the scarcity and unavailability of sand, an alternate is choosen to measure the rate of workability of SCC using quarry rock dust. The main property and strength of SCC depends on its workability[1] Hence workability tests and its relative compressive strength have been conducted to measure SCC specimens with fine aggregate and quarry rock dust. Fluidity of the paste can be improved by increasing the content of water-powder ratio and by adding super plasticizers. Segregation and blockages can be avoided by reducing the coarse aggregate content. A viscosity modifying agent (VMA) helps to reduce the changes in concrete properties[2]. Thus, relative proportions of ingredients need to be carefully determined to impart self leveling and self compacting properties to SCC in the fresh stage. Thus SCC specimens have been casted with quarry rock dust and fine aggregate using three different bases of superplasticizers(HRWRA) such as polycarboxyl, naphthalene and melamine bases and VMA. And its workability and strength properties have been evaluated by conducting different tests.

Regression Analysis by Taguchi Method on Strength of Weathered Crystalline Rock Sand Concrete

Due to industrialisation, large constructions are going on all over the world which in turn requires huge quantity of cement and sand. Cement manufacture is a main source of carbon-di-oxide emission to the atmosphere and quarrying of river sand produces scarcity as well as environmental problems. There are various waste products obtained from manufacture of other materials as well as from quarries, the handling of which is difficult and creates environmental issues. These waste materials can be used as a replacement for cement and sand. In this study weathered crystalline rock sand which is obtained from the soft outer portion of rock in quarries is used as replacement for river sand and Ground Granulated Blast-furnace Slag (GGBS) obtained from iron industry is used as replacement for cement to reduce the environmental impact as well as to help waste handling and reuse.

Mechanical Strength Properties of Geo Polymer Concrete incorporating Quarry Rock Dust and Recycled Coarse Aggregate

Utilization of waste materials in concrete are increasing day by day. Ingredient replacements in concrete using waste materials are one of such threads which bind nature and concrete in a greener way to provide a better environment for the future. Reduction in environmental pollution, effective usage of waste management, the economic factor and quality of concrete are the predominant aspects by which the replacement materials are chosen.[1] Geopolymer Concrete has emerged as one of the possible alternatives to OPC, since 100% of fly ash is used instead of Portland Cement.. In this present study, the prime material which is used as the source material is fly-ash (ASTMC618) which completely replaces cement..Also fine aggregate has become very expensive and scarcity, quarry rock dust have been replaced for fine aggregate. Almost all the demolition and construction waste have been dumped without any usage which ultimately results in pollution.[2] This prime factor is considered to reutilize recycled coarse aggregate instead of coarse aggregate . A greener aided with natural friendly claim can be made only with the usage of the waste materials. To find the better combination mix, the GPC is categorized into four types as GPC-1, GPC-2, GPC-3 and GPC-4. In all the above combination of mixes fly ash is used as prime source material whereas QRD and RCA are replaced with different combinations. Thus this paper, particularly focuses on the effect of replacement of waste materials in combination of different mixes such as FA+CA, QRD+CA, FA+RCA, and QRD+RCA in GPC. The casted specimens are cured at ambient temperature and after three days of rest period, the casted specimens are tested to determine its mechanical strength properties using standard methodology.

Altered visual environment affects a tropical freshwater fish assemblage through impacts on predator–prey interactions

Abstract Increased turbidity and siltation caused by rock quarrying, mining, and deforestation are pervasive disturbances in aquatic systems. Turbidity interferes with vision for aquatic organisms, potentially altering predator–prey interactions. We studied the effects of these disturbances in Trinidadian streams by surveying predators and their shared prey both in streams with versus without quarries as well as in a focal stream before and after the establishment of a quarry. Then, to evaluate whether differential foraging success in turbid water might underlie abundance patterns of predators, we experimentally induced turbidity in mesocosms and measured predator foraging success. Upstream quarry presence had a dramatic effect on the benthic structure of streams, greatly increasing siltation. A substantial decrease in the abundance of a diurnal cichlid predator (Crenicichla frenata) was associated with quarry presence, while a nocturnal erytherinid predator (Hoplias malabaricus) was equally as abundant in streams with or without quarries. The density of their shared prey, the Trinidadian guppy (Poecilia reticulata) remained unchanged. In mesocosm trials, Crenicichla were less successful predators with turbidity, whereas Hoplias performed equally across turbidities. These foraging success results help explain differences in demographic shifts in response to turbidity for both predators. By relating short‐term effects of an anthropogenically altered visual environment on species interactions to abundance patterns of predators and prey, this study helps to identify an important mechanism whereby changes to species’ visual ecology may have long‐term effects on population biology.