Fine Aggregate In Concrete Research Articles

Comparative study on the performance of fresh concrete comprising manufactured sand vs. river sand during full-scale long-distance pumping

The shift from river sand (RS) to manufactured sand (MS) as a fine aggregate in concrete is driven by environmental sustainability concerns. However, negative impacts of MS on concrete workability have raised doubts about its suitability for long-distance pumping in construction projects. This study evaluates the performance of MS concrete compared to RS concrete of the same strength grade during long-distance pumping. A full-scale coiled pipeline with measured length of 348 m was built, twelve batches of C30 and C60 concrete were prepared, and pumping tests were conducted at discharge rates of 2.5–18.9 liter per second (L/s). The workability and rheological parameters were assessed before and after pumping. The measured and predicted pumping pressure were analyzed and calculated based on rheological parameters and lubricating layer (LL) parameters. Results indicate that MS increased the yield stress and decreased the LL thickness index of C30 concrete, while it decreased the viscosity coefficient of C60 concrete. Post-pumping, the change in yield stress was similar for both MS and RS concrete, but MS reduced the plastic viscosity change in C60 concrete. MS did not significantly affect the pumping pressure loss, but influenced the pumping pressure prediction deviation by influencing the thixotropy. The classic pumping pressure prediction model developed by Kapan obviously overestimated the pumping pressure during long-distance pumping, and the deviation was more prominent in high-strength concrete pumping. MS increased the thixotropy of C30 concrete and reduced the prediction deviation of pumping pressure, but had the opposite effect on C60 concrete.

Research on freeze resistance and life prediction of Desert sand–Crushed stone fine aggregate concrete

Despite the global abundance of Desert sand (DS), its application in engineering remains limited. This application can help alleviate challenges related to high unit costs and the scarcity of natural fine aggregate supplies. Freeze resistance experiments were conducted on C30 concrete incorporating varying proportions of DS, including 0 %, 25 %, 50 %, 75 %, and 100 %. DS was mixed with Tuff crushed stone fine aggregate (Manufactured sand, referred to as MS). The freeze durability of the composite fine aggregate concrete was comprehensively evaluated from three perspectives: surface morphology, a macroscopic analysis including mass loss and relative dynamic elastic modulus (RDEM), and microscopic examinations encompassing pore structure observation and scanning electron microscope (SEM) imaging. Utilizing the damage degree index of the dynamic elastic modulus and the Weibull distribution model, the life prediction process was conducted to elucidate the time-varying behavior of DS-MS concrete. According to the test findings, the concrete specimen DS25-MS75 demonstrates the highest freeze resistance. The mass loss rate shows a pattern of initial decrease followed by an increase with higher desert sand admixture, whereas the RDEM initially increases and then decreases. Optimal desert sand admixture levels can prevent and delay concrete degradation, thereby enhancing its freeze resistance. Excessive desert sand content leads to increased water demand during the curing process, resulting in elevated porosity and facilitating the formation of voids. Under the action of freezing and thawing cycles in water, DS25 %-MS75 % concrete has the longest expected service life with an actual life of 101 years, while DS100 %-MS0 % concrete has the shortest service life with an actual life of only 54.5 years.

Microbial self-healing cement-based materials co-reinforced by Mg2+: using recycled aggregates as carriers

Microbial self-healing cementitious materials have attracted widespread attention due to their targeted repair of cracks, but their practical application is limited by cost. In this study, self-healing mortar was prepared using recycled concrete fine aggregate as a cementitious material to investigate the effect of magnesium ions on crack repair, to explore the compatibility of self-healing components and cement, and to assess the cost and environmental impact of this self-healing mortar. The results showed that the mineralization efficiency was the highest at 31.1% with a Ca/Mg molar ratio of 3, and the 28 d crack repair rate reached 97.8%; yeast and peptones in the self-repairing system slowed down the rate of cement hydration, whereas magnesium chloride and calcium lactate facilitated the hydration reaction. The use of recycled concrete fine aggregate (RCA) reduces the cost of the self-repairing material and the CO2 emission, and improves the application of microbial self-healing cementitious materials potential.

Sustainable use of recycled fine aggregates in steel fiber-reinforced concrete: Fresh, flexural, mechanical and durability characteristics

Recycling construction waste is a viable tactic for advancing environmentally friendly building methods. With regard to concrete applications, the purpose of this research is to determine whether it is feasible to use recycled fine concrete aggregates (RFA) in lieu of natural fine aggregates (NFA) and to lessen the environmental impact of natural resource depletion and landfill space. A sustainable steel fiber-reinforced concrete was created by replacing NFA with RFA at the replacement ratio of 0 %, 50 %, and 100 %. Steel fibers (SF) were also included to mixes at three different contents of 0, 25 and 50 kg/m3 in order to further improve the qualities of the concretes. Thus, the aim of this paper is to appraise how the addition of FRA affects the mechanical, freeze-thaw, fresh, and non-destructive qualities of concrete. Nine concrete mixtures were cast, and tests were made to evaluate the following properties: flowability, fresh concrete unit weight, tensile and compressive strengths, elastic modulus, surface hardness, crack mouth opening displacement (CMOD), freeze and thaw performance, sulfate resistance and abrasion. Moreover, microstructure properties of concrete were also analyzed. The outcomes revealed that the mechanical, flexural, and durability performances of the concrete mixtures were enhanced by substituting RFA for NFA. The mixture with 50%RFA and 50 kg/m3 SF gained maximum compressive strength of 44.82 MPa which was 20.7 % greater than the reference mixture (RFA0F0). The mixture containing 100 % RFA and 25 kg/m3 SF had the highest elastic modulus and showed an approximately 33 % augmentation in elastic modulus as per the reference mixture. The mixture with 100%RFA and 50 kg/m3 SF exhibited the largest tensile strength indicating 60 % tensile strength enhancement as per the reference mixture. Combined use of RFA and 50 kg/m3 SF in concrete mixtures had the best abrasion and freeze-thaw resistance. SF incorporated concrete mixtures with RFA exhibited worse sulfate resistance. This study contributed significantly to global resource efficiency and environmental preservation by shedding light on the sustainable use of RFA and SF in the making of concrete. The results made important contributions to global research and promote environmentally friendly building methods all throughout the world.

Recycle of steel slag as cementitious material and fine aggregate in concrete: mechanical, durability property and environmental impact.

Using steel slag (SS) as cementitious material and fine aggregate in concrete is an effective and environmental method for SS consumption and cost reduction. In this paper, SS was recycled in large volumes in concrete as partial cementitious material and fine aggregate. The compressive strength and reaction mechanism of cementitious material with different SS powder contents including 20%, 25%, 30%, and 35% were presented. The results indicated that 20% of SS powder improved the compressive strength by 34.57% and the hydration products were ettringite (AFt) and calcium silica hydrate(C-(A)-S-H). Furthermore, the mechanical and durability performance of concrete with SS as fine aggregate were investigated. When the SS substitution rate was 75%, the compressive strength was increased by 37.83%. The volume shrinkage rate and 28d-carbonation depth were reduced nearly by 64% for 90days and 2.33mm, respectively. The chloride ion penetration resistance reached the optimal grade Q-V and abrasion resistance was improved by nearly 24%. Along with the reduced CO2 by 210-294kg/m3 and the decreased cost by 12.61 USD/m3, it is regarded as an effective method to consume steel slag. As such, this research provided a scientific and systematic basis for the large-scale disposal and utilization of industrial waste residues as well as recycled materials preparation.

Using crushed stone dust as a substitute for fine aggregates in concrete

Generation of waste from mining and high consumption of natural aggregates resulting from civil construction works have significant economic and environmental impacts. Aiming to use the stone dust residue from the rock crushing process, this study experimentally evaluates the use of crushed stone dust as a partial substitute for fine aggregates in concrete with a compressive strength of 30 MPa, thus providing an alternative in civil construction activities. Crushed stone dust was evaluated through physical, chemical, mineralogical, petrographic, and micromorphological characterization tests. The characterization results indicated that the material is classified as medium and fine sand, with 68.2% silicon dioxide and quartz peaks, i.e., similar to natural sand. Axial compression tests were performed on twenty cylindrical specimens with diameters of 100 mm and heights of 200 mm, broken at 28 days. Five of such specimens were made of reference concrete, without stone dust, while fifteen contained concretes with stone dust. In this approach, the percentage of stone dust in the concrete specimens ranged between 20%, 50%, and 100%, and compressive strength was kept constant at 30 MPa, with five cylinders with stone dust for each percentage of sand replacement. The results show the contribution of stone dust to the mechanical behavior of the concrete specimens, which corroborate the possibility of applying it as a substitute for fine aggregates, as compressive strength was higher in the concrete specimens with 20% and 50% stone dust compared to the reference concrete.

Fracture properties and acoustic emission characteristics of manufactured sand recycled fine aggregate concrete

To promote the application of recycled fine aggregates, fracture characteristics of concrete beams containing manufactured sand (MS) and recycled fine aggregate (RFA) were investigated. The fracture properties and acoustic emission (AE) characteristics of manufactured sand recycled fine aggregate concrete (MSRFAC) with 0 %, 25 %, 50 %, 75 % and 100 % RFA replacement rates were evaluated by three-point bending test of single-sided notched beams. The fracture mechanisms of MSRFAC beams were explored using AE and digital image correlation (DIC) techniques, and fracture process zone (FPZ) was qualitatively and quantitatively analyzed. The results indicated that the critical nominal stiffness, initial fracture toughness, fracture energy and characteristic length of MSRFAC decreased significantly with the increase of RFA replacement rate, up to 20.2 %, 37.7 %, 22.8 %, and 26.6 %, respectively, while the unstable fracture toughness was insensitive to the variation of RFA. Moreover, the AE activity, the tensile crack, large-scale crack, high amplitude, and high peak frequency in MSRFAC increased with increasing RFA replacement rate. According to the FPZ characteristics of MSRFAC, its FPZ length increased with the increase of RFA replacement rate, while the FPZ width decreased with the increase of RFA replacement rate. The critical FPZ lengths of MSRFAC with different RFA replacement rates were about 20.2–30.0 mm, and the maximum FPZ widths were about 26.0–36.7 mm. The RFA weakened the friction mechanism and interlocking effect between aggregates of MSRFAC, resulting in a faster FPZ propagation rate and smaller damage width of MSRFAC than normal manufactured sand concrete.

Mechanical, durability and microstructural properties of waste-based concrete reinforced with sugarcane fiber

Extensive research has focused on producing sustainable concrete by exploring waste and recycled materials as alternatives to virgin substances. However, waste-based concretes often exhibit inferior durability and mechanical performance compared to traditional concrete. Incorporating reinforcement agents can enhance their performance. This study investigates the use of sugarcane fiber as a reinforcement in waste-based concretes containing fly ash (FA), ground granulated blast furnace slag (GGBS), and recycled concrete fine and coarse aggregates (RFA and RCA). Five dosages of sugarcane fibers (0 %, 1 %, 2 %, 3 %, and 4 % by fine aggregates mass) were examined. Mechanical and durability tests, including compressive strength, flexural strength, water absorption, and chloride ion penetration, were conducted. Scanning electron microscopy and micro-porosity analysis were employed for further assessment. Results show that adding sugarcane fiber enhances the waste-based concrete properties, with 3 % being the optimal dosage. This dosage improves compressive strength by 16 %, flexural strength by 35 %, flexural load bearing capacity by 34 %, energy absorption by 107 %, and toughness index by 6 %, while reducing water absorption by 4 % and chloride ion penetration by 23 %. Further increases in fiber dosage decrease concrete properties. The enhanced behavior is attributed to reduced porosity, refined pore structure, and reduced microcrack propagation. This study underscores the potential of incorporating sugarcane fiber along with waste materials to develop eco-friendly composites, aiming to mitigate carbon dioxide emissions and address environmental concerns.

Durability analysis of metakaolin recycled concrete under sulphate dry and wet cycle

This study aims to enhance the durability, cost-effectiveness, and sustainability of recycled fine aggregate concrete (RFAC) subjected to the combined effects of wet-dry cycles and sulfate erosion. Dry–wet cycle tests were conducted in RFAC with different admixtures of biotite metakaolin (MK) and 15% fly ash (FA) mix (M) under 5% sulfate erosion environment. The effect of 0%, 30%, 60% and 90% recycled fine aggregate (RFA) replacement of natural fine aggregate on mass loss, cubic compressive strength, relative dynamic modulus test of RFAC, damage modeling and prediction of damage life of concrete were investigated. The results showed that the concrete cubic compressive strength and relative dynamic modulus were optimal for recycled concrete at 15% MK biotite dosing and 60% RFA substitution, and its maximum service life was accurately predicted to be about 578 cycles under 5% sulfate dry–wet cycling using Weibull function model. This study is pioneering in addressing the durability of RFAC under sulfate attack combined with wet-dry cycling, employing a novel approach of incorporating MK and FA into RFAC. The findings highlight the practical application potential for using MK and FA in RFAC to produce durable and sustainable construction materials, particularly in sulfate-exposed environments. This research addresses a critical challenge in the construction industry, providing valuable insights for developing more durable and eco-friendly construction materials and contributing to long-term sustainability goals.

Exploring the Use of Iron Ore Tailings in Concrete by Partial Replacement of Fine Aggregates

Concrete is the most durable, resilient, available and affordable material in the built environment. The manufacture of large quantities of iron ore has created difficulties for the environment and disposal. The utilization of IOT as fine aggregate in building material production is relatively feasible. Experiments were conducted to determine the suitability of iron ore tailings as replacement of fine aggregates for concrete. The iron ore waste was collected from Gua Iron Mines, Singhbum. Mix Design was carried out for concrete of grade M35 using standard practice for selecting proportions for normal weight. Iron ore waste replaced with fine aggregates in mixes by 30% and 35% respectively. The materials used for M35 grade of concrete is coarse aggregate 10-20mm, fine aggregate is of Zone 2, cement of 53 grade. Tests were performed on materials, for cement and fine Aggregate Fineness test, Specific Gravity were performed. Water absorption test, specific gravity, Impact value these were performed for Coarse aggregate. It was observed that compression values of concrete for 30% for 3 days its 13.703 Mpa, For 7 days its 16.503 Mpa, and for 28 it was 28.033 Mpa

Experimental Study of Mechanical Properties and Theoretical Models for Recycled Fine and Coarse Aggregate Concrete with Steel Fibers.

With diminishing natural aggregate resources and increasing environmental protection efforts, the use of recycled fine aggregate is a more sustainable approach, although challenges persist in achieving comparable mechanical properties. Exploration into the incorporation of steel fibers with recycled aggregate has led to the development of steel-fiber-reinforced recycled aggregate concrete. This study investigates the shrinkage performance and compressive constitutive relationship of steel fiber recycled concrete with different steel fibers and recycled aggregate dosages. Initially, based on different replacement rates of recycled coarse aggregate and different volume contents of steel fiber, experimental results demonstrate that as the replacement rate of recycled coarse aggregate increases, shrinkage also increases, while the addition of steel fiber can mitigate this effect. An empirical shrinkage model for steel fiber recycled concrete under natural curing conditions is also proposed. Subsequently, based on the uniaxial compression test, findings indicate that with an increasing replacement rate of recycled fine aggregate, the peak stress and elastic modulus of concrete decrease, accompanied by an increase in peak strain, and the addition of steel fiber limits concrete crack development and enhances its brittleness while the peak stress and strain of recycled fine aggregate concrete are enhanced. However, the steel fiber volume percentage has a negligible effect on the elastic modulus. A constitutive relationship for concrete considering the effects of recycled fine aggregate and steel fiber is also proposed. This finding provides foundational support for the influence patterns of steel fiber dosage and recycled aggregate ratio on the mechanical properties of steel fiber recycled concrete.

Experimental investigation on partial replacement of coconut shells as coarse aggregate and rubber as fine aggregate in concrete

Experimental investigation on partial replacement of coconut shells as coarse aggregate and rubber as fine aggregate in concrete

Sustainable self-Compacting concrete with marble slurry and fly ash: Statistical modeling, microstructural investigations, and rheological characterization

The escalating generation of marble waste and the substantial carbon footprint associated with cement production pose significant environmental challenges. Thus, by substituting fly ash for supplementary cementitious material and using leftover marble waste for fine aggregate in concrete can reduce cost and carbon emissions that may lead to sustainable development. The presented paper aims to study the effect of partial substitution of marble slurry with natural fine aggregates and fly ash as supplementary cementitious material (SCM) on Self-Compacting Concrete (SCC). Polycarboxylate Ether (PCE) based superplasticizer (SP) was added in the concrete mix, to decrease the demand of higher water to binder (w/b) ratio. After developing SCC, fresh state properties and compressive strength (CS) at the curing age of 7 and 28 days were evaluated. To maximize the utilization of marble slurry and fly ash, mixture optimization was performed using the Box-Behnken Design (BBD), a robust technique within the response surface methodology (RSM) framework. Rheological analysis was performed to analyse the fresh state behaviour of the SCC with the help of the Bingham and Modified Bingham (MB) models. Field emission scanning electron microscopy (FE-SEM) and X-ray diffraction (XRD) studies were also carried out to study the behaviour of the marble slurry and fly ash in the concrete. Carbon emission and cost analysis of SCC was evaluated at different replacement level of the marble slurry and fly ash. It was inferred that marble slurry and fly ash can be used in the certain percentages without compromising any strengthen and flowability properties of the SCC. The rheological behaviour also confirmed that linear and nonlinear behaviour of SCC in the certain mix proportion may results in the formation of the stable SCC. The analysis of cost and carbon emission confirmed that sustainable SCC mixture achieved substantial reductions of 21.44 % in cost and a remarkable 47.71 % decrease in carbon dioxide (CO2) emissions compared to conventional concrete.

Properties of concrete containing spent garnet as fine aggregate replacement

Abstract The use of river sand as a construction material has become a critical concern in many countries. Excessive mining for concrete production is one of the main issues that lead to environmental pollution. Simultaneously, environmental concern over discarding spent garnet from industry have led to research on using it as a partial replacement for fine aggregate in concrete. Different mixtures incorporating 10 %, 20 %, and 30 % spent garnet were studied to assess their impact on concrete’s workability, mechanical strength, and durability. This study used a concrete mix design to create concrete mixes for 48 cubes. Three types of tests such as slump, compressive strength, and water absorption test were conducted to evaluate the concrete’s properties. The findings indicate that as the amount of spent garnet used in concrete increases, the concrete becomes more workable. The optimum strength results were achieved when 20 % of the fine aggregate was replaced with spent garnet. Furthermore, concrete with up to 20 % spent garnet had lower water absorption compared to the control mix. Utilizing spent garnet as a substitute for sand in construction not only fosters sustainability but also addresses the challenge of effective waste disposal.

Environmental impacts and performance assessment of recycled fine aggregate concrete.

Natural disasters and human demolition create vast amounts of construction and demolition waste (CDW), with a substantial portion being concrete waste. Managing this concrete waste is a daunting challenge for developing countries with limited resources, aiming to mitigate its harmful environmental effects. Therefore, the proposed approach involves using recycled fine aggregates (RFA) instead of fresh fine aggregates (FFA) in concrete, which aligns closely with achieving sustainable environmental objectives. Extensive laboratory tests were conducted to assess the effects of adding RFA to concrete. The influence of 0 to 100% RFA replacement and different curing times was investigated on compressive strength, tensile strength, resistance against chloride ion penetration and chemicals exposure, and quality of aggregates. So, around 30%, 35%, 20%, and 79% reductions in compression strength, tensile strength, modulus of elasticity, and workability were estimated when 100% RFA was used in recycled aggregate concrete (RAC). However, according to results analyses, the performance of RAC is reliable up to 50% of RFA in proposed conditions and mix design. In addition, major environmental impacts such as global warming potential, aquatic eutrophication, and aquatic acidification were reduced by 47%, 40%, and 18%, respectively, for concrete having 50% RFA than concrete having 100% FFA.

Carbonation resistance of recycled fine aggregate concrete reinforced by calcium sulfate whiskers

This study investigates mechanical and carbonation resistance tests conducted on Recycled Fine Aggregate Concrete (RFAC) with three different Recycled Fine Aggregate (RFA) replacement rates and four calcium sulfate whisker (CSW) contents, and investigates the effects of RFA replacement rate and CSW content on the mechanical properties of RFAC and the carbonation resistance of RFAC with calcium sulfate whiskers at different ages of carbonation. The microstructure of CSW-modified RFAC was observed and analyzed by SEM electron microscopy to explore further enhancement and toughening mechanisms of CSW in RFAC, as well as the optimal content of CSW in RFAC. In addition, the carbonation depth of recycled concrete with calcium sulfate beard is modeled based on a quadratic fitting formulation. The test results show that the mechanical properties and carbonation resistance of RFAC would decrease with the increase of the RFA replacement rate. Incorporating CSW can effectively improve the mechanical properties and carbonation resistance of RFAC. At 60 % RFA substitution, CSW at 2 % content has the most significant effect on the mechanical properties and carbonation resistance of RFAC. Microscopic analysis shows that CSW has a bridging effect at the micro-cracks in the concrete matrix, preventing the creation and expansion of micro-cracks in the concrete matrix, thus improving RFAC mechanical properties of RFAC and resistance to carbonation. The predicted results of the carbonation depth model which are constructed from the test data coincide with the results. We can use them to predict and analyze the carbonation depth of the carbonation resistance of recycled concrete.

Utilisation of Waste Shea Nutshell Fine-Grained Particles to Enhanced Strength and Durability Behaviour of Concrete

Shea nutshells possess properties that stabilise soil enough to resist water penetration. It is a waste material and incorporating it as an additive material in concrete will be a means by which it can be recycled. With this projection, the study incorporated shea nutshell particles (SSP) as fine aggregates in concrete. The aim was to determine their influence on strength and durability properties. Fine aggregates were partially replaced with 0%, 10%, 20%, 30%, and 40% SSP based on the weight of the aggregate, and labelled as A0, S10, S20, S30 and S40 respectively. Concrete cubes of size 150 mm and cylinders of diameter 150 mm and height of 300 mm were prepared and cured for 7, 14, 28, and 90 days. The concrete was tested for density, compressive strength, split tensile strength, water absorption, and sulphate attack. The inclusion of the SSP did not improve the compressive and split tensile strengths. However, water absorption and sulphate attack decreased with further addition. Though, strength properties did not appreciate, values at 10%, 20% and 30% additions in 28 and 90 days satisfied the 28 days minimum requirement of 25 N/mm2. Hence, the study recommends the use of SSP in concrete production up to 30%.

Compressive Behaviors of High-Strength Geopolymeric Concretes: The Role of Recycled Fine Aggregate

In this study, natural fine aggregates (NFAs) in high-strength fly ash (FA)/ground granulated blast furnace slag (GGBFS)-based geopolymer concretes were both partially and completely replaced by RFAs to prepare geopolymer recycled fine aggregate concrete (GRFC). Herein, the impacts of RFA content (0%, 25%, 50%, 75%, and 100%) on the fresh and hardened performance and microstructural characteristics of a GRFC were investigated. The results indicated that with increasing RFA substitution ratio, the setting time of the GRFC decreases. In addition, the compressive strength and elastic modulus decrease. However, owing to the enhanced adhesion of the geopolymer matrix and recycled aggregate, RFA has a relatively small impact on the compressive strength, with a maximum strength loss of 9.7% at a replacement level of 75%. When the RFA content is less than 75%, the internal structure of the concrete remains relatively compact. The incorporation of RFA in concrete has been found to adversely affect its compressive strength and elastic modulus, while simultaneously increasing its brittleness. The increase in dosage of RFA leads to a reduction in the compressive strength and elastic modulus of concrete, while partial failure occurs when the GRFC constitutes 100% of the RFA. The existing stress–strain model for conventional concrete is recalibrated for the GRFC. Observed by SEM, with increasing RFA, the damage is mainly concentrated at the interface associated with the attached cement. Although the recalibrated model predicts the stress–strain responses of the GRFC reasonably well, an acceptable range of deviation is present when predicting the residual stress due to the relatively high strength and brittle behavior of the GRFC during compression. Through this research, the applicability of RFA is expanded, making it feasible to apply large quantities of this material.

Effects of elevated temperature exposure on the mechanical properties of recycled fine aggregate concrete

ABSTRACT In this work, a compound waste material was made up of raw construction waste concrete, waste tiles, and waste bricks was mixed at a weight ratio of 6:3:1. They were ground into recycled fine aggregates (RFA). RFA substituted the local river sand in proportions of 0%, 30%, 50%, 70%, and 100% for preparing recycled fine aggregate concrete (RFAC) with varied water-to-cement ratios. It intended to explore concrete’s mechanical properties and ultrasonic pulse velocity changes before and after high temperatures (300–800°C). The loss on ignition (LOI) of concrete was simultaneously determined to compare the performance in resisting elevated temperature. Test results presented that the higher the replacement ratio of RFA, the gradually higher the reduction in the concrete splitting tensile, compressive, and residual compressive strengths and ultrasonic pulse velocity after elevated temperature exposure. A rapid reduction was especially found at the heated temperature of exceeding 440°C. Furthermore, the old cement paste adhered to the surface of the raw construction waste had a relatively higher LOI. This led to the consequence that the RFAC had an increased LOI with the increment of the RFA replacement ratio, while the LOI of RFAC dropped with the increment of the originally heated temperature.

Feasibility Study on the Use of Iron Ore Tailings as Fine Aggregate with Glass Fibre in Concrete

Concrete is the most widely used building material in the world, but its production has significant environmental consequences, including high carbon emissions and natural resource depletion. As a result, there is an increasing interest in the development of sustainable concrete technologies that reduce concrete’s environmental footprint while maintaining its performance and durability. Partially replacing fine aggregate with industrial waste is one such approach. It is a great practice for developing sustainable concrete that can help with environmental problems caused by the dumping of these waste materials at the same time maintaining the performance of concrete. It also provides economic and social benefits in addition to the environmental benefits. iron ore tailings is one such industrial waste that is the by-product of iron ore beneficiation process which has shown the potential for partial replacement of fine aggregate in concrete. In addition, glass fibre is added to improve the tensile property of concrete. A concrete mix of M20 grade were prepared by replacing fine aggregate with iron ore tailing at replacement level 15%, 25%, and 35% and the optimum replacement percentage was obtained. Further, glass fibre was added at the dosage of 0.5% by the weight of cement to the mix with optimised replacement of iron ore tailings and tests were conducted. This work also examines concrete’s physical, mechanical and durability properties with partial replacement of fine aggregate with iron ore tailings and glass fibre by conducting tests on strength and durability. Results obtained indicates incorporation of iron ore tailing with concrete reduces the workability of concrete, and the addition of glass fibre improved the compressive strength and split tensile strength. Durability tests show an increase in water absorption with the addition of iron ore tailings and a medium level of chloride penetration. The study showed the use of iron ore tailing as a sustainable alternative to fine aggregate in concrete.