Granite Aggregate Research Articles

Performance assessment of a rock aggregate heat exchanger exposed to daily temperature variation

Opportunities exist to utilize rock aggregate to condition ventilation air at mine sites in humid continental climates. Vale’s Creighton mine in Canada proved that a natural heat exchanger offered significant energy savings; however, the system was not suitable to establish design guidelines. A novel prototype-scale outdoor 30 m3 rock pile heat exchanger experiment was constructed to characterize the thermal response to measurable aggregate parameters with insight shared regarding their sensitivity. This paper validates an unsteady 3D CFD numerical methodology involving the thermal non-equilibrium porous zone model with lab-scale-derived correlations against weather-influenced temperature data and proposes guidelines for improving performance: Increasing pile flatness was beneficial for damping whereas increasing hemispericality was beneficial for phase shifting. A CFD case study requiring 47 m3/s (100,000 cfm) ventilation flow found that a rock pile constructed using traditional methods could achieve 100% damping with 6,000 m3 of granitic rock aggregate at a pressure penalty of 2,500 Pa.

Experimental investigation on the effects of a new anti-stripping additive on performance properties of asphalt and its mixtures

• A new compound anti-stripping additive called DMA-NSDD was developed. • The asphalt and its mixture performance was investigated by experiments. • A comparison was made of the performance of seven asphalts and their mixtures. • The performance of asphalt with DMA-NSDD and its mixtures was markedly improved. This study aims to investigate the effects of a new compound anti-stripping additive called DMA-NSDD, which comprised dopamine methacrylamide (DMA) that is a marine biomimetic material and nano-silicon dioxide dispersion (NSDD), on the performance properties of asphalt and its mixtures by experiments. The main steps of DMA synthesis were described. The test methods used in this study for asphalt and asphalt mixture performance were also introduced. The performance properties of asphalt with DMA-NSDD and its mixtures were investigated by comparing with those of virgin asphalt, styrene–butadienestyrene (SBS) modified asphalt, anti-stripping asphalts DMA, NSDD, LYKB™, and GLWS™, and their mixtures. Results showed that the marine biomimetic material DMA could be used in asphalt and its mixtures to increase their performance properties. Compared with SBS, DMA, NSDD, LYKB™, and GLWS™, the asphalt–aggregate adhesion and water stability of the asphalt mixtures with DMA-NSDD were the best and enhanced most significantly. The high- and low-temperature performance of the asphalt mixtures with DMA-NSDD was also notably improved, although it was second only to that of the SBS-modified asphalt mixtures. Overall, with DMA-NSDD, the performance properties of asphalt mixtures with granite aggregates improved more than those of asphalt mixtures with limestone aggregates.

INFLUENCE OF SODIUM AND POTASSIUM FORMATE ON THE ASR REACTIVITY OF GRANITE AGGREGATE

Use of de-icing agents is necessary in winter to maintain appropriate quality of road and airport surfaces. Formate or acetate de-icing agents are safer for aircraft and the environment than the commonly used sodium chloride, but may cause an alkali-silica reaction in concrete. The study investigated the influence of sodium formate and potassium formate on the occurrence of ASR (alkali-silica reaction) in mortars with granite aggregate. Accelerated mortar-bar tests at 80°C using various de-icing agents were performed and detailed studies of the SEM-EDS microstructure were carried out.

Concrete impact strength as a measure of the resistance of a structure to external destructive energy

This paper presents authors’ own tests of the impact strength of concrete. The impact tests were carried out using a pendulum ballistic hammer, two types of concrete with natural aggregate: with pebble (river) gravel aggregate and medium-grained crushed granite aggregate. The concretes were tested on cubic specimens with varying W/C ratios (0.40; 0.45; 0.50; 0.55). The surface roughness of the grains in the aggregates used for the concretes was measured using a profilometer. Concrete impact strength was determined by the energy absorbed by the specimen until failure. Concrete impact strength (EA) was compared with compressive strength (fc), tensile strength (fct) and stress intensity factor (K1c).

Ex-situ and In-situ Manufacturing Procedures for Optimizing the Characteristics of a Soil Concrete Based on Lateritic Gravels and Granitic Aggregates: Application in Road Construction

Ex-situ and In-situ Manufacturing Procedures for Optimizing the Characteristics of a Soil Concrete Based on Lateritic Gravels and Granitic Aggregates: Application in Road Construction

Performance of Porous Asphalt Mixtures Containing Recycled Concrete Aggregate and Fly Ash.

This study investigates the effects of two waste materials from construction and industry, namely recycled concrete aggregate (RCA) and Type C fly ash, on the overall performance of a special type of pavement surface mixture, porous asphalt mixture. Mixtures of different combinations of RCA (for partial aggregate replacement) and fly ash (for filler replacement) were prepared in the laboratory and tested for a variety of pavement surface performance parameters, including air-void content, permeability, Marshall stability, indirect tensile strength, moisture susceptibility, Cantabro loss, macrotexture, and sound absorption. The analysis of the results showed that incorporating RCA or fly ash in a porous asphalt mixture slightly reduced the air-void content, permeability, and surface macrotexture of the mixture. A 10% replacement of granite aggregates with RCA in the porous asphalt mixtures led to a reduction in mixture stability, indirect tensile strength, resistance to raveling, and sound absorption. The further substitution of mineral filler with fly ash in the mixture, however, helped to offset the negative impact of RCA and brought the mechanical properties of the mixture with 10% RCA to levels comparable to those of the control mixture.

Adhesion Characterization of Palm Oil Mill Sludge Modified Asphalt Binder

The adhesion of mineral aggregates to asphalt binder is an essential point that attributes to the quality and performance of the asphalt mixture. Moreover, the considerable problem to the asphalt pavement could come from the lack of bonding between the materials. Generally, adhesion of mineral aggregates depends on the source or type of aggregate and asphalt binder. This study investigated the adherence coverage of palm oil mill sludge (POMS) modified binder with granite aggregate. Base asphalt binder of penetration grade 60/70 was blended with 1%,2%,3%,4% and 5% of POMS to produce the modified asphalt binders, respectively. Consequently, POMS modified binders were mixed with the granite aggregate to produce loose mix samples. In this current study, boiling test procedure was used to reduce the adhesive bonding of the loose mix sample. Then, Image J software was used to evaluate the stripping area of the samples. The results from image analysis revealed that different stripping areas due to different amounts of POMS incorporated in the modified asphalt binder. Up to 4% POMS modified asphalt showed an acceptable resistance toward moisture compared to un-modified asphalt. Image J helped to produce a clear stripping result compared to visual observation. In conclusion, POMS could be used as an asphalt modifier with satisfactory adhesion properties.

Effect of Antistripping Additives on the Cohesion, Adhesion, and Performance of Different Asphalt Mixtures in Dry and Wet Conditions

Most available tests of asphalt mixture performance against moisture damage or the effect of additives examined the asphalt mixture’s overall performance. Considering the different mechanisms of moisture damage, studying antistripping additives’ effect on failure mechanisms might provide a better view of the asphalt mixture’s performance against moisture. Accordingly, herein, the effects of various antistripping additives, including a liquid antistripping additive (dodecylamine) and a nano-magnesium hydroxide additive, each at two bitumen weight percentages, with two types of aggregates with different mineralogical properties and a PG 64-16 bitumen on moisture damage mechanism were investigated. The cohesion and adhesion mechanisms of moisture damage were examined using the pull off test, and the asphalt mixture’s overall performance was assessed using the indirect tensile strength (ITS) test in multiple dry and wet conditions (1, 2, and 3 freeze-thaw cycles) according to the modified Lottman test. The results revealed that the use of 0.4% dodecylamine and 1% nano-magnesium hydroxide in the mixtures made with lime aggregates increases the tensile strength ratio (TSR) from 62.67% to 85.4% and 84.8%, respectively. In mixtures made with granite aggregates, TSR increased from 54.45% to 72.49% and 71.35%, respectively. The failure mechanisms’ assessment showed that the use of 1% nano-magnesium hydroxide in mixtures made with granite aggregate elevated the pull off in the adhesion failure mechanism by 80%, and the pull off increased by 70% in the cohesion failure mechanism. Moreover, the pull off increased by 63% for limestone mixtures in the cohesion failure mechanism and by 56% in the adhesion failure mechanism. The dodecylamine additive with the highest pull off and ITS ratio in all freeze-thaw cycles was more suitable than nano-magnesium hydroxide to promote the asphalt mixtures’ overall performance against moisture. The statistical analysis also indicated the significant effect of dodecylamine and nano-magnesium hydroxide additives on asphalt mixtures’ moisture sensitivity reduction at a 95% confidence level. The findings show that some additives have a stronger effect on adhesion strength and some effect on cohesion strength, but the additive that better improves the overall asphalt mix performance depends on mix design characteristics and aggregate and bitumen type.

THE FIRE RESISTANCE OF CONCRETE MADE WITH RECYCLED PLASTIC AS PARTIAL REPLACEMENT FOR COARSE AGGREGATE

This research is aimed to investigate the fire resistance of recycled discarded plastic when used as partial replacement for normal granite coarse aggregate in concrete when exposed to elevated temperatures. Discarded Polyethylene Terephthalate (PET) bottles were cut into a maximum size of 20mm to produce Recycled Plastic Aggregate (RPA). The replacement of normal aggregates with RPA were in proportion of 0%, 5%, 10%, 15%, 20%, 25% and 30% by weight of normal coarse aggregate. The compressive performance of the concrete made with RPA were studied by casting three 100 mm cubes for each of the percentage replacements and tested at 7, 14 and 28 days of curing age. A set of three (3) concrete cubes for each percentage replacement was cured for 28 days and subjected to a temperature of 718oC for a duration of 15 minutes in a furnace. Results of slump tests on fresh concrete showed that workability decreased with increase in RPA. Densities and compressive strengths for normal cube samples not subjected to elevated temperatures and the sample subjected to temperature of 718oC increased with increase in curing age and decreased with increase in percentage of RPA. The result showed that the concrete specimen with 10% replacement of RPA was optimum for good thermal stability.

Effect of Aggregate Type on Properties of Ultra-High-Strength Concrete.

In this work, we present an analysis of natural fine aggregates’ influence on the properties of ultra-high-strength concrete. The reference concrete mix was made of natural sand with the addition of fly ash and microsilica. It was assumed to obtain concrete with a very high strength without the addition of fibers and without special curing conditions, ensuring the required workability of the concrete mix corresponding to the consistency of class S3. The reference concrete mix was modified by replacing sand with granite and basalt aggregate in the same fractions. Five series of concrete mixes made with CEM I 52.5R cement were tested. Experimental investigations were carried out regarding the consistency of the concrete mix, the compressive strength, the flexural strength and the water absorption by hardened concrete. A comparative analysis of the obtained results indicated significant improvement in the concrete strength after the use of basalt aggregate. The strength of the concrete series based on basalt aggregate, BC1, allowed it to be classified as ultra-high-performance concrete. Concrete based on sand, SC1, was characterized by the lowest compressive and flexural strength but obtained the best workability of the mix and the lowest water absorption. The results presented in the paper, show a significant influence of the type of aggregate used on the mechanical and physical properties of ultra-high strength concrete.

The Influence of the Type of Cement on the Properties of Surface Cement Concrete.

The aim of this work was to reduce the carbon footprint of cement concrete by using multi-component cement with a high content of blast furnace slag. The analysis consisted of comparing the properties of the concrete mix and the hardened concrete made of the CEM I 42.5 R-NA cement commonly used in Poland and the CEM III cement with a large amount of blast furnace slag. The tests used cement in a constant amount of 380 kg/m3, granite aggregate of 2/8, 8/16, 16/22 mm and sand of 0/2 mm. As part of this project, detailed tests of the concrete mix and hardened concrete were carried out in terms of compressive, bending, fracture and frost resistance after 150 cycles of freezing and thawing, and the pore structure in hardened concrete was assessed according to PN-EN 480-11. The endurance tests were performed after 7, 28 and 90 days. On the basis of the obtained results, it was found that the highest compressive strengths above 70.2 MPa were obtained for concrete with CEM III, 64.5 MPa for concrete with CEM I. Additionally, for concrete with multi-component cement, smaller drops in compressive strength were obtained and a more favorable pore distribution in hardened concrete was obtained. Concrete intended for road surfaces can be made of both CEM I and CEM III cement, as they meet the requirements of the technical specifications for roads with heavy traffic of heavy vehicles.

Strength Variability and Its Relationship with Microstructure of Coarse Granite Aggregates

Strength Variability and Its Relationship with Microstructure of Coarse Granite Aggregates

A Study on Correlation between Ultrasonic Pulse Velocity Method and Coarse Aggregate for Estimating Residual Modulus of Elasticity of Concrete Exposed to High Temperatures

In this study, the mechanical properties of normal concrete (NC) and lightweight concrete (LC) were measured upon exposure to high temperatures (20, 100, 200, 300, 500, and 700 °C). Then, analysis was conducted to predict the residual modulus of elasticity through ultrasonic pulse velocity. Crushed granite aggregate was mixed as the coarse aggregate for NC and coal-ash aggregate for LC. The effect of the water-to-binder (W/B) ratio (0.41, 0.33, and 0.28) on the mechanical properties (residual compressive strength, residual ultrasonic pulse velocity, residual modulus of elasticity, and stress–strain) of concrete was determined. The residual compressive strength, residual ultrasonic pulse velocity, and residual modulus of elasticity were higher for LC compared to NC. The correlation between the ultrasonic pulse velocity and residual modulus of elasticity was also analyzed, which yielded a high correlation coefficient (R2) at all levels. Finally, equations for predicting the residual modulus of elasticity using ultrasonic pulse velocity with R2 values of 0.94 and 0.91 were proposed for NC and LC, respectively.

Presentation of thermodynamic and dynamic modules methods to investigate the effect of nano hydrated lime on moisture damage of stone matrix asphalt

ABSTRACT Stone matrix asphalt (SMA) mixtures are the most resistant type of asphalt mixtures today in which the aggregate skeleton bears the bulk load. In this study, the effect of nano hydrated lime (NHL) on the moisture sensitivity of SMA mixtures was investigated. To examine the effect of NHL, the surface free energy (SFE) method and the dynamic modulus (DM) test were applied under wet and dry conditions on mixtures constructed with limestone and granite aggregates. The SFE results indicated that the granite aggregates had a greater polar component and limestone aggregates had a higher non-polar component which shows their higher moisture resistance. The adhesion free energy (AFE) results showed that the adhesion of base bitumen and limestone aggregate was higher, and using NHL improved the AFE values. The results of DM tests indicated that as the load cycles raised, the wet to dry DM ratio reduced and using NHL increased this ratio. The reduction slope of the DM ratio in samples constructed with granite aggregates showed a faster trend compared to limestone aggregates, and using NHL improved the resistance of SMA mixtures constructed with granite aggregates to moisture more than limestone aggregates.

Study on Laterite Aggregate on Concrete Strength

The research was conducted to collect previous research that talked about the performance of laterite aggregates used in the production of concrete mix with the addition of fly ash. The later aggregate is chosen because it is widely distributed in a tropical country such as Malaysia and Indonesia and the main objectives of this research are to determine the effect of laterite aggregate on the strength of concrete, to determine the comparison of the strength of concrete containing laterite aggregate and granite aggregate. To determine the effectiveness of laterite concrete aggregate using fly ash. Use a compressive strength test. The aggregate will be stronger and more durable when exposed to sunlight and the rain can also replace laterite aggregates in place of the granite aggregate in the future and the descriptive method was used and information was collected to know the performance and effectiveness of concrete in terms of its new properties.

Analysis of Ultrasonic Pulse Velocity Correlations for Estimating Residual Compressive Strength of Concrete Subjected to High-Temperature Hysteresis: Influence of Various Aggregates

In this study, the compressive strength and ultrasonic pulse velocity (UPV) behaviors of concrete at high temperatures by aggregate type were comparatively analyzed in accordance with the CEN and CEB Codes. The aggregates adopted were divided into limestone, granite, river gravel, and crushed stone, and the target temperatures were set to 100 °C, 200 °C, 300 °C, 400 °C, 500 °C, and 600 °C. The analysis items were specified as compressive strength (Fc), UPV, ratio of compressive strength (Fcratio), and UPV ratio (UPVratio); in addition, the correlations between Fcratio and UPV were analyzed and compared to the previously proposed estimation equations for concrete at room temperature. Accordingly, the Fcratio of limestone and river gravel aggregates exceeded the UPVratio at temperatures lower than 300-400 °C; however, UPVratio tended to be higher at subsequent temperatures. For granite aggregates, UPVratio was higher than Fcratio over the entire temperature range, while crushed stone aggregates exhibited higher Fcratio than UPVratio. Both Fcratio and UPVratio of granite aggregates exceeded those of limestone aggregates, while the UPVratio and Fcratio of river gravel aggregates were higher and lower than those of crushed stone aggregates, respectively. Consequently, a strength estimation equation was proposed by analyzing the correlations between Fcratio and UPV, and was inferred to be better than the existing strength estimation equations.

Exemplification of sustainable sodium silicate waste sediments as coarse aggregates in the performance evaluation of geopolymer concrete

This investigation presents the experimental studies on mechanical properties of geopolymer concrete (GPC) developed with the addition of sodium silicate waste sediments (SSW) as coarse aggregates. Conventional crushed granite coarse aggregate (CA) was replaced by SSW from the sodium silicate manufacturing plant. The GPC was developed by replacing the natural CA with SSW from 0% − 70% with a trend in exercising circular economy in the concrete. The GPC with 100% CA was used as the control specimen to compare the results of different replacement levels of SSW. A low calcium Fly ash (FA) and Ground granulated blast furnace slag (GGBS) were used as binder materials, along with sodium hydroxide and sodium silicate solutions as activator solutions. The sodium hydroxide of 4 M and sodium hydroxide to sodium silicate ratio of 1:1.5 were used in the development of the mixes. Two types of curing conditions namely, ambient and oven curing were adopted. The M30 grade design mix was used for control and CA replaced specimens. The mechanical properties such as compressive, tensile, and flexural strengths along with the elastic modulus of GPC at the ages of 7-, and 28-day were investigated. Microstructural analysis was conducted to examine the influence of SSW on the strength characteristics of GPC. The analyses were performed to evaluate the energy requirement and CO2 emission of GPC and OPCC (Ordinary Portland Cement Concrete) in the production of 1 m3 concrete based on the previous literature. The significance of the proposed research work emphasizes the utilization of waste SSW as an aggregate material for the development of GPC. Therefore, a sustainable GPC mix can be developed with lower energy requirement and CO2 emission. The results revealed that the specimens with 40% SSW cured at 60 °C produced the targeted strength of 34.6 MPa. Meanwhile, the mixes with 40% − 70% of SSW exhibited superior performance in terms of cost and eco-efficiencies.

Effect of specific heat capacity of aggregates and nano-graphite on self-healing of hot mix asphalt under microwave radiation

This paper aimed to investigate the effect of nano-graphite (NG) as a conductive additive and specific heat capacities of aggregates on the self-healing performance of the asphalt mixtures. In this research, three types of aggregates, including Limestone, Granite, and Dolomitic Limestone, with different contents of NG (5%,10%, 20%, and 30% by the weight of bitumen) were used. The indirect tensile tests (IDT) were applied to evaluate the microwave healing capability of broken samples. The healing index (HI) analysis showed that the optimum amount of NG was 10% by weight of bitumen, which restored tensile strength in healed samples above half of their original strength. Also, it was found that among the mixtures containing optimum NG, the sample with Granite aggregate consumes 16% and 30% less heating energy than samples with Dolomite Limestone and Limestone aggregates, respectively. In addition, results indicated that the HI of broken samples in the 24-hour rest period at ambient temperature has increased by 15 to 30 % compared to the 12 h.

Effect of Spent Garnet Waste as Partial Fine Aggregate Replacement on Properties of High Strength Lightweight Aggregate Concrete

As time goes on, the usage of natural resources for concrete production affects the environment. Both the quarrying activities for granite aggregate harvesting and sand mining destroys the environment. At the same time, industrial by-products namely palm oil clinker (POC) and spent garnet waste which thrown as waste, also cause pollution. The inclusion of spent garnet waste as fine aggregate replacement in POC lightweight aggregate concrete production would reduce the consumption of river sand. This research investigates the effect of using spent garnet waste as a fine aggregate replacement on workability, dry density, and compressive strength of POC lightweight aggregate concrete. Five concrete mixes were prepared by varying the percentage of spent garnet waste as a fine aggregate replacement up to 40% by the weight of fine aggregate. All concrete specimens underwent water curing until the testing age of 7 and 28 days. The specimens were tested to determine dry density and compressive strength. Overall, the use of spent garnet as partial fine aggregate replacement influences the concrete properties. Inclusion of 20% spent garnet in concrete resulted in formation of semi-lightweight concrete with density of 2240 kg/m3. On top of that, the concrete with spent garnet exhibit higher compressive strength of about 60MPa which is about 14% higher than control specimen. Conclusively, the utilization of spent garnet as a partial fine aggregate replacement would save river sand consumption and reduce the dumping of spent garnet.

Effect of Coal Bottom Ash as Partial Sand Replacement for Lightweight Aggregate Concrete

Environmental degradation due to disposal of waste namely coal bottom ash waste from thermal power plant, clinker waste of palm oil mill and river sand mining activity for concrete production need to be resolved. Palm oil clinker lightweight concrete with zero granite aggregate that been produced in effort to reduce dependency of natural stone consumption has been further explored its potential in this research. Thus, the present research investigates the compressive strength, water absorption and acid resistance of lightweight aggregate concrete containing coal bottom ash as partial sand replacement. Five types of concrete mixes were produced using 0%, 10%, 20%, 30% and 40% coal bottom ash as fine aggregate replacement. After curing process, specimens were immersed in acid hydrochloric solution before subjected to compressive strength testing. Findings show that all specimen experience strength reduction after exposed to acidic environment. On overall, the use of coal bottom ash influences the durability performance of lightweight aggregate concrete.