Natural Sand Research Articles

Waste glass as a substitution for binder and sand in concrete: mechanical and physical properties

Replacing cement with glass powder (GP) and natural sand with glass sand (GS) in concrete could provide a compelling pathway to a sustainable construction to reduce environmental impacts of both concrete and waste glass. An experimental investigation on concrete, where cement is substituted by GP, fly ash (FA), and ground granulated blast furnace slag (GGBS) and natural sand is substituted by GS, is presented. 17 mixes were considered, and workability, density, elastic modulus, compressive strength, and water absorption were evaluated. Results indicate that the GP particle size significantly affects the concrete properties. Increasing the GP particle size decreases the concrete compressive strength and elastic modulus. The replacement of cement with GGBS at a 55% level has a positive effect on the mechanical characteristics of GP concrete, with an average enhancement of 11% in the compressive strength and 4% improvement in the elastic modulus at 28 days. Replacing sand by the GS at up to 25% develops comparable mechanical properties to those of conventional concrete, with only a 3% and 2% reduction in 28-day compressive strength and elastic modulus, respectively. 50% GS and 35% GGBS develops similar mechanical properties in the waste-based concrete in comparison to the conventional concrete. Incorporating 55% GGBS or 15% FA/40% GGBS reduces concrete water absorption when compared to that of cement-based concrete.

Ultra-High-Performance Concrete with Local Materials as Overlay Reinforcement of Slab Structural

This research is an initial study on the strengthening of the existing normal reinforced concrete slab structure with Ultra-High-Performance-Concrete (UHPC) overlay using local materials without nano materials. The study began with the production of a UHPC mixture referring to a previous researcher, Meng (2017), with the type of SCM as a research variable. The cement used was OPC I, with the composition of SCM: silica fume content of 10%, 15%, and 20% with a fixed fly ash content of 15%. The maximum size used is the aggregate that passes the 4.75 mm sieve, is a combination of crushed stone (55%) and natural sand (45%). The ratio of water binder, w/b used is 0.22, superplasticizer content is 1% of the total weight of cementitious materials, and steel fiber content is 2% of the volume of concrete. Tests were carried out on the mechanical properties of UHPC. The results of the highest compressive test of the UHPC mixture, applied as an overlay on normal reinforced concrete slabs, became a hybrid composite structural element, which was then tested under flexural loads using the third point method. In addition to hybrid composite panels, a normal reinforcement concrete slabs were also made as a control specimen. The dimensions of the test specimens for the hybrid composite plate are 1000 mm x 400 mm x 60 mm and the thickness of the UHPC overlay is 20 mm thick. The test results show that the highest compressive strength of concrete was achieved by the mixture with the composition of SCM: 15% silica fume and 15% fly ash, which is 74.13 MPa at the age of 7 days; and at the age of 28 days obtained 65.17 MPa; thus, lower than the compressive strength of UHPC in general. However, the application of the highest performance concrete mix as overlays reinforcement for normal reinforced concrete slab has quite an effect on the hybrid composite slab. With the overlay, there is an increase in the flexural load capacity and ductility of the slab structure by 71%, and 166.22%, respectively. In addition, there is a difference in the stiffness behavior of the slab structure, in normal reinforced concrete structures, the stiffness would decrease after the first crack appears; however, in this hybrid composite structure, the stiffness will increase after the crack appears. The hybrid composite slab's crack pattern propagation behavior is also improved and distinct.

Utilization of Coal Bottom Ash as a Natural Sand Replacement in Mortar Containing Fly Ash

The substantial generation of waste ashes from coal thermal power plants (CTP), particularly fly ash (FA) and bottom ash (BA), poses significant environmental challenges; meanwhile, the exhaustion of natural river sand for the construction industry is more serious. The study aims to explore the use of BA as a sand replacement and FA as a partial cement substitute in mortar production, focusing on sustainability. In this research, FA and cement served as binder materials, with FA comprising 15% of the total binder mass. BA was incorporated as a fine aggregate, replacing sand at varying levels of 0%, 25%, 50%, 75%, and 100% by weight. The study assessed the effects of BA substitution on the mortar's compressive strength (CS), ultrasonic pulse velocity (UPV), water absorption (WA), thermal conductivity (TC), and resistance to sulfate attack. Additionally, scanning electron microscopy (SEM) was utilized to analyze the mortar's microstructure. Results indicate that substituting sand with BA negatively impacted all tested properties. As BA content increased, CS, UPV, and TC of mortar samples decreased, while WA and sulfate expansion increased markedly. At 56 days, the mortar samples exhibited CS values ranging from 20.6 to 57.0 MPa, UPV values from 3395 to 4203 m/s, WA values from 5.58% to 18.70%, and TC values from 0.89 to 1.73 W/m·K. Furthermore, the control mortar demonstrated a length change of 0.0218% due to sulfate attack, whereas the length changes for specimens with 25%, 50%, 75%, and 100% BA replacement were approximately 68.8%, 96.3%, 155.0%, and 162.4% higher, respectively.

Replacing Sand in Concrete: Review on Potential for Utilization of Bottom Ash from Combustion of Wood in Circulating Fluidized Bed Boilers

Aggregates such as sand and gravel are the most mined resources on Earth and are the largest component in concrete. They are essential for construction but are becoming increasingly scarce. At the same time, large amounts of biomass ashes are produced in wood-fired power plants, offering potential as a partial substitute for decreasing sand resources. Due to the combustion technology of circulating fluidized bed boilers, their bottom ash offers high potential as a viable alternative to natural sand. This review examines previous research to assess the feasibility of replacing sand in concrete with bottom ash. Specific cementitious products are identified, where the substitution could realistically be performed in the concrete industry. Benefits and issues with partial substitution of bottom ash from wood combustion are discussed, and gaps in the research regarding sand replacements with bottom ash, notably the durability of the resulting concrete, are shown. Bottom ash has positive properties relevant for use in mortar and concrete, both regarding physical and chemical properties. Although limited research exists in the field, several researchers have demonstrated promising results when substituting sand for bottom ash in mortars. For lower substitution levels, little effect on the fresh and hardened properties is found.

Freezing desert soil changes the wind–sand movement pattern

In the Ulan Buh Desert, which is located in a seasonally frozen region, a frozen soil layer can appear in the winter after the wind erosion of dry sand from the surface of a mobile sand dune, thus altering the wind–sand transport process. To clarify the wind–sand transport pattern after the emergence of a frozen soil layer, this study used wind tunnel experiments to study the variations in the wind erosion rate and sediment transport pattern of frozen and nonfrozen desert soil with different soil moisture contents (1–5%). The results revealed that the relationships of the wind speed, soil moisture content and wind erosion rate are in line with an exponential function, and the wind erosion rate decreases by 6–52% after the desert soil is frozen. When the soil moisture content of the nonfrozen desert and frozen desert soil is 4% and 3%, respectively, the wind erosion rate of the soil can be reduced by more than 65% compared with that of natural dry sand (soil moisture content of 0.28%), i.e., the wind erosion rate can be effectively reduced. The sediment transport rate of nonfrozen desert soil decreases with increasing height, with an average ratio of approximately 65% for saltation. The sediment transport rate of frozen desert soil first increases but then decreases with increasing height, with an average ratio of approximately 80% for saltation. When sand particles hit the source of frozen desert soil, the interaction between particles and bed surface is dominated by the process of impact and rebound, so that more particles move higher, and some sand particles move from creep to saltation. In summary, freezing has an inhibitory effect on the wind–sand activity of desert soil, and freezing makes it easier for sand to move upwards.

Failure analysis and damage characterization of steel fiber reinforced manufactured sand concrete column under axial compression

AbstractManufactured sand (MS) is a beneficial and sustainable supplement to natural sand (NS). This study investigated the mechanical properties of manufactured sand concrete (MSC) columns under axial compression. The effects of test parameters including MS replacement rate, reinforcement ratio, slenderness ratio, and steel fiber content on the failure modes, concrete strain, stiffness, and flexibility, etc., were analyzed and demonstrated. The results showed that the MS replacement rate and reinforcement rate presented less effect on the concrete strain, whereas decreasing the slenderness ratio of the specimens and increasing the steel fiber contents significantly increased the strain of the concrete. The 100% MS replacement rate exhibited little effect on the strain of concrete and the stiffness of members, while the bearing capacity was increased to 9.3% compared with the 0% MS replacement rate. Incorporating steel fibers significantly improved MSC's mechanical properties and increased the members' strength and flexibility. In addition, the constitutive model of MSC was established, and the model's accuracy was verified based on finite element analysis, which exhibited favorable accuracy with an error of less than 5%.

Crushed Stone Utilization in replacing Silica Sand in Ultra-High Performance Concrete

Ultra-High Performance Concrete (UHPC) offers superior load-bearing capacity and durability, yet its reliance on natural Silica Sand (SS) contributes to high production costs and environmental concerns. This study examines the feasibility of substituting SS with Crushed Stone (CS) aggregates in UHPC production. Through a combination of theoretical analysis and experimental investigation, an optimal mixture is identified, and the effects of CS aggregates on key UHPC properties, including flowability, air bubble content, and compressive strength, are evaluated. The experimental results indicate that UHPC incorporating CS aggregates achieves compressive strengths exceeding 130 MPa at 28 days. The Scanning Electron Microscopy (SEM) analysis reveals that the Interfacial Transition Zone (ITZ) surrounding CS aggregates exhibits lower local stiffness due to the predominance of calcium hydroxide (CH) and ettringite crystals. Furthermore, the microstructural analysis identifies the presence of elongated particles (accounting for up to 32% of the mixture) and microcracks within the CS aggregates, which contribute to a reduction in compressive strength. Consequently, UHPC produced with CS aggregates achieves approximately 84% of the compressive strength of UHPC utilizing SS aggregates. Despite this reduction in mechanical performance, the cost-effectiveness of CS-based UHPC is significantly superior, with a 29% reduction in the overall production costs and a 16% improvement in the cost-to-performance ratio compared to SS-based UHPC. These findings demonstrate that CS aggregates provide a viable and economically advantageous alternative to SS in UHPC production, offering significant cost savings while maintaining the essential mechanical properties required for structural applications.

Strength performance and microscopic mechanism of cement mortar incorporating fine recycled concrete aggregate and natural sand

Strength performance and microscopic mechanism of cement mortar incorporating fine recycled concrete aggregate and natural sand

Sustainable use of recycled sand in alkali-activated cement and Portland cement mortars: A comparative study with natural sand

Sustainable use of recycled sand in alkali-activated cement and Portland cement mortars: A comparative study with natural sand

Enhancing the shear strength of sand through capsule-enclosed tung oil: a self-healing approach

The development of self-healing soil emerges as a possible solution to provide an autonomous and sustainable geomaterial to ground infrastructure with enhanced durability. This study aimed at developing a capsule-enclosed healant to enhance the shear strength of sand. Encapsulated tung oil was released in sand from calcium alginate capsules when subjected to void ratio changes under compaction. The released tung oil will harden and bond sand grains after a 30-day drying period. The release amount of tung oil was tracked at different void ratios (0.754–0.976) and capsule dosages (0.99%–3.85%), with its effect on strength evaluated by drained triaxial compression tests. The inclusion of capsules with fresh (liquid) tung oil decreased the peak strength and dilatancy of sand. However, enhanced peak strength/stress ratio compared to natural sand at effective confining stress of 50–100 kPa was achieved after stabilization with aged (hardened) tung oil. The critical state line of the sand-capsule composites located below that of clean sand in e-p′ plane, with the lines almost converging in the q-p′ plane. The role of tung oil bonding was separated and explained in terms of bonding energy. The combined effect of capsule dosage and bonding on peak strength were quantitatively captured. The soft capsule decreased friction angle while the bonding contributed to cohesion increase, leading to peak strength enhancement at mean effective stress lower than 500 kPa.

Palm fruit bunch fiber impact on compressive strength of cement mortar with different fine aggregate types

Depletion of high-quality natural sand deposits and sustainability concerns are popularizing manufactured sand use in cementitious composites. Meanwhile, palm fruit bunch fiber (PFBF) improves the properties of cementitious composites, but it is unclear how PFBF interacts with different fine aggregates to affect mortar strength. This study investigated the impact of PFBF on the compressive strength of cement mortars containing manufactured sand (granite quar- ry dust) and natural sands (river and pit). The aggregates were used with Portland cement to fabricate mortar cubes, which were tested after 28 days. The control mortars (0% PFBF) of quarry dust, river sand, and pit sand recorded strength of 24.2 MPa, 21.5 MPa, and 10.4 MPa, respectively. At the optimum fiber content, the strength of the quarry dust and pit sand mor- tars increased marginally to 24.7 MPa and 12.2 MPa, respectively. However, river sand mortar strength considerably increased to 26.1 MPa. Interestingly, the quarry dust and pit sand mortars generally experienced strength loss before reaching their peak at 2.0% and 2.5% fiber content, respectively. In comparison, river sand mortar consistently gained strength before peaking at 2.5% PFBF. Hence, pre-optimum fiber contents could enhance river sand mortar strength but hinder quarry dust and pit sand mortar strengths. By standardizing the PFBF-reinforced mortar strengths against the control strengths, PFBF enhanced pit sand mortar strength the most, fol- lowed by river sand mortar, but it mainly reduced quarry dust mortar strength. Mortar design must, therefore, optimize PFBF dosage considering the unique characteristics of each sand type.

Investigation on Mix Proportions of Ultra-High Performance Concrete with Recycled Powder and Recycled Sand

The construction waste of brick and concrete can be used to produce recycled powder and recycled sand, which can replace cement and natural sand, respectively, in concrete. This can reduce the cost of concrete, reutilize construction waste and decrease environmental pollution. The idea of producing UHPC incorporating both RP and RS by standard curing instead of steam curing is proposed in this study. The optimal mixture design of ultra-high-performance concrete (UHPC) with both recycled powder and recycled sand is investigated. Based on the revised Dinger–Funk model, the optimal mix proportions of green UHPC (GUHPC) with recycled powder and recycled sand were calculated on this basis, and the effects of the superplasticizer content, water–binder ratio, recycled powder and recycled sand replacement ratio on the workability and mechanical properties of GUHPC at different ages were investigated through the designed experimental program. The test results show that when the superplasticizer to cementitious material ratio was 0.8%, the flowability and the 28 d compressive strength were highest. When the water–binder ratio was 0.16, the flexural strength and compressive strength of the GUHPC at different ages were the largest. As the replacement ratio of the recycled powder increased, the workability of the GUHPC decreased. However, even when replacement ratio of recycled powder was 30%, the flowability was still higher than 180 mm. The flexural strength and the 28 d compressive strength increased first and then decreased. Compared with mixtures without RP, the 28 d compressive strength increased by 6.4% and reached the maximum value when the replacement ratio of the RP was 30%. The comprehensive contribution of recycled powder to the strength was analyzed. Recycled powder can enhance the contribution of cement to GUHPC strength, and the enhancement effect increases with increases in the recycled powder content and age. The optimal replacement ratio of recycled powder is 30%. As the replacement ratio of the recycled sand increased, the flowability of the GUHPC first increased and then decreased, and the flexural and compressive strength decreased. The toughness was analyzed by the flexural strength to compressive strength ratio (f:c). With increases in the recycled sand, the f:c at 3 d of age increased, the f:c at 7 d of age showed no significant change, and the f:c at 28 d of age first increased and then decreased. The f:c at 28 d of age reached a maximum value of 0.316 when the replacement ratio of recycled sand was 50%. Therefore, the replacement ratio of the recycled sand was selected to be 50%. The optimum mix proportions of GUHPC were obtained by considering the workability, mechanical properties and amount of recycled material.

Strength and Durability of Concrete with Quarry Dust as a Sand Substitute

Abstract Growth has increased demand for natural sand, producing depletion and environmental difficulties. Quarry dust—a byproduct of rock crushing—is studied as a sustainable substitute for natural sand in M40-grade concrete. Significant effects on workability and compressive strength at various replacement weight percentages of 10%, 20%, 30%, and 40% are the main focus. According to IS 10262-2019 and IS 516-1959, 45 concrete samples were cast, cured, and evaluated at 7, 14, and 28 days. Replacing up to 20% of fine aggregate with quarry dust boosts compressive strength. The peak strength after 28 days was 46.35 MPa, significantly less than the average mix's 47.23 MPa. Performance diminishes beyond this threshold, with strengths decreasing to 35.21 MPa at 30% replacement levels and 34.04 MPa at 40%. The results show that quarry dust can replace natural sand due to its similar physical and chemical properties. Use of recycled industrial waste in concrete saves sand supply, decreases environmental harm, and supports circular economy. This study revealed that sustainable concrete production at 20% replacement may retain durability and strength. Quarry dust's environmental benefits may help the building industry become greener and more resource-efficient. Keywords: M40 Concrete Mix, Quarry Dust, Fine Aggregate Replacement, Sustainable Construction, Compressive Strength.

Experimental Investigation On Strength Properties Of Concrete With GGBS Sand, M Sand And Flyash

In order to lessen concrete's negative effects on the environment, this article explores the possibility of using fly ash as a cement substitute. It goes on to say that fly ash may make concrete last longer and work better mechanically. The compressive strength of concrete was determined to be unaffected by the substitution of M sand for natural river sand in this experimental investigation. Additionally, it was shown that although using up to 15% fly ash as cement substitute somewhat boosts compressive strength, further increases in fly ash steadily lowers it. The impact of using GBS in place of natural fine aggregate on concrete mix characteristics was the subject of this investigation. Compressive and tensile strengths were also enhanced in GBS-bound concrete, according to the research.

Analyzing the effect of reduced graphene oxide on the physical, mechanical, and long-term durability performance of rubberized concrete

Crumb rubber concrete (CRC) modified with reduced graphene oxide (rGO) is examined to repurpose discarded tires with crumb rubber (CR) replacing natural sand in the proportions of 5, 10, and 15% and rGO replacing cement by 0.05, 0.10, and 0.15%. Thirteen mixes containing different proportions of rGO and CR were made. Workability and density tests were carried out on fresh CRC samples; while tests for compressive strength, tensile strength, and flexural strength were carried out at test periods of 28, 56, and 90 days. Acid attack, water sorptivity, and fire resistance tests were carried out after 90 days. Non-destructive tests like rebound hammer and ultrasonic pulse velocity were carried out after 28 days of curing. The results indicate an increase in the compressive strength, tensile strength, and flexural strength up to 18.7, 3.86, and 10%, respectively, including 0.1% rGO in the CRC. Non-destructive test results confirm the improved performance of rGO-modified concrete. Significant reductions in water sorptivity, mass, and compressive strength after acid exposure were also observed, indicating the enhanced durability due to the addition of rGO in CRC. Fire exposure at 200, 400, and 600 °C, resulted in compressive strength reductions of 10.56, 17.47, and 37.29%, respectively in the mixes.

Coastal Environments: LiDAR Mapping of Copper Tailings Impacts, Particle Retention of Copper, Leaching, and Toxicity

Tailings generated by mining account for the largest world-wide waste from industrial activities. As an element, copper is relatively uncommon, with low concentrations in sediments and waters, yet is very elevated around mining operations. On the Keweenaw Peninsula of Michigan, USA, jutting out into Lake Superior, 140 mines extracted native copper from the Portage Lake Volcanic Series, part of an intercontinental rift system. Between 1901 and 1932, two mills at Gay (Mohawk, Wolverine) sluiced 22.7 million metric tonnes (MMT) of copper-rich tailings (stamp sands) into Grand (Big) Traverse Bay. About 10 MMT formed a beach that has migrated 7 km from the original Gay pile to the Traverse River Seawall. Another 11 MMT are moving underwater along the coastal shelf, threatening Buffalo Reef, an important lake trout and whitefish breeding ground. Here we use remote sensing techniques to document geospatial environmental impacts and initial phases of remediation. Aerial photos, multiple ALS (crewed aeroplane) LiDAR/MSS surveys, and recent UAS (uncrewed aircraft system) overflights aid comprehensive mapping efforts. Because natural beach quartz and basalt stamp sands are silicates of similar size and density, percentage stamp sand determinations utilise microscopic procedures. Studies show that stamp sand beaches contrast greatly with natural sand beaches in physical, chemical, and biological characteristics. Dispersed stamp sand particles retain copper, and release toxic levels of dissolved concentrations. Moreover, copper leaching is elevated by exposure to high DOC and low pH waters, characteristic of riparian environments. Lab and field toxicity experiments, plus benthic sampling, all confirm serious impacts of tailings on aquatic organisms, supporting stamp sand removal. Not only should mining companies end coastal discharges, we advocate that they should adopt the UNEP “Global Tailings Management Standard for the Mining Industry”.

Evaluating thermal storage capability of recycled construction materials: an experimental approach

Granular materials like sand have gained importance in thermal storage applications due to their stability and cost-effectiveness. However, excessive usage of sand can pose environmental issues. This study investigates recycled construction materials such as glass, asphalt, ceramic, and concrete as alternatives to natural sand for low-temperature TES applications. The materials were processed to similar grain sizes and evaluated for their chemical, thermophysical, and thermal storage properties through a six-hour charging cycle at 60 °C. XRF analysis revealed significant compositions, including high oxygen and silicon content in concrete and sand, respectively. Results indicate that sand with 0.189 W/m K recorded the highest thermal conductivity compared with concrete 0.172 W/m K, glass 0.131 W/m K, ceramic 0.159 W/m K and asphalt 0.159 W/m K. A higher specific heat capacity was observed in concrete at 755 J/kg K, followed by asphalt at 732 J/kg K, glass at 708 J/kg K, and sand at 688 J/kg K. However, ceramic is categorized for a lower specific heat capacity of 682 J/kg K. Absolute density evaluation indicates that sand is the densest material with 2662 kg/m3, contrary to concrete 2480 kg/m3, glass 2421 kg/m3, ceramic 2285 kg/m3, and asphalt 2436 kg/m3. More to the point, the Ragone plot for specific power and energy highlighted that ceramic has a rapid energy release and concrete demonstrated sustained energy storage capabilities. Volumetric power and energy density assessments indicated sand's outstanding performance. However, concrete registered a superior thermal storage among recycled materials. The results highlight that recycled materials, specifically concrete can be used for thermal storage applications like water heating in poor communities.

Mechanism of turbulence modulation of sediment-laden flow for the case of equilibrium suspended-load transport

The interphase interaction between water flow and sediment and particle collision in sediment laden flow will modulate the flow turbulence. Due to the complexity of suspended sediment movement, the mechanism of water-sediment interaction has always been a difficult point in the study, especially the modulation law of water-sediment interaction on flow turbulence has not reached a consistent conclusion. It is of great significance for the study of sediment laden flow to optimize the construction of the numerical model of water and sediment. In this study, a Euler solid–liquid two-phase flow model was used to investigate the effects of drag force, density gradient, and particle collisions generated by natural sand and plastic sand on flow characteristics under the condition of different sediment concentrations for the case of equilibrium suspended-load transport, so as to determine the degree of influence of various factors in the numerical simulation process on the turbulent flow properties. Results showed that the presence of sediment particles changes the flow velocity, sediment concentration distribution, and turbulent energy distribution, and that such effects strengthen with increase in sediment concentration. The effects of drag force and particle collisions on the resistance coefficient and on flow velocity are dominant. The drag force tends to reduce the resistance coefficient and increase flow velocity, whereas particle collisions produce the opposite effect. The density gradient and particle collisions are the dominant factors affecting the turbulent diffusion coefficient of the suspended load and the vertical distribution of the sediment concentration. However, they produce opposite effects that partially cancel each other. With increase in sediment concentration, the effect of sediment particles on the turbulence of sediment-laden flow increases; the drag force and density gradient inhibit turbulence, and particle collisions promote turbulence.

Mechanisms and characteristics of sand seepage deformation under groundwater level fluctuation scenarios

Mechanisms and characteristics of sand seepage deformation under groundwater level fluctuation scenarios

Effectiveness of microbial-induced carbonate precipitation for mitigating the hydraulic erosion of the riverbank.

Effectiveness of microbial-induced carbonate precipitation for mitigating the hydraulic erosion of the riverbank.