Conventional Fine Aggregate Research Articles

Evaluation of Iron Ore Tailings From the Fundão Dam Failure in Mariana-MG As A Partial Substitute For Conventional Fine Aggregates in Cement Mortars

Evaluation of Iron Ore Tailings From the Fundão Dam Failure in Mariana-MG As A Partial Substitute For Conventional Fine Aggregates in Cement Mortars

Microstructure and residual strength properties of engineered geopolymer composites (EGC) subjected to high temperatures

This study investigates the effects of high temperature on the microstructure and residual compressive strength properties of engineered geopolymer composites (EGC). The importance of this study focusses on the performance and durability of EGC, aiming towards sustainable construction practices. The proposed study fills the knowledge gap by the use of steel fibers (SF) as primary reinforcement in EGC, specifically involving a combination of Fly Ash (FA), Basic Oxygen Furnace (BOF) slag, and Iron Ore Tailings (IOT). The residual properties of EGC under high-temperature conditions were assessed by preparing cube specimens (50 mm) involving FA and BOF slag as primary precursors, with IOT as a partial replacement to conventional fine aggregate (M-sand) and brass-coated SF as discrete reinforcement. The specimens were exposed to temperatures up to 1000 °C in a muffle furnace in six different levels: 25, 200, 400, 600, 800, and 1000 °C. Post-exposure, the specimens were ambient cured prior to testing of pore structure distribution, residual strength properties, and microstructural characteristics involving scanning electron microscopy (SEM) analysis. The experimental findings show that, despite various combinations of precursors, IOT and SF, no explosive deterioration or spalling occurred in EGC mixes at any level of exposure. Also, as the exposure temperature increased, the compressive strength decreased while the strain capacity enhanced, denoting an increase in the stiffness of the EGC mixes. Notably, the SF maintained its structural integrity even at 1000 °C, which was consistent with the observed microstructural behavior. This indicates the proposed EGC exhibits excellent resistance to elevated temperatures and enhanced strain-hardening capacity. Overall, this research provides valuable insights into the residual properties and microstructural characteristics of FA: BOF: IOT-based EGC, highlighting its potential as a sustainable and fire-resistant building material. The outcomes contribute significantly to the existing knowledge on EGC and its application in environments exposed to high temperatures.

Mechanical and microstructural properties of municipal solid waste incinerator bottom ash (MSWIBA) concrete exposed to salt erosion and drying-wetting cycles

In cold and saline soil areas, concretes usually experience multi-factor erosions, such as freezing-thawing cycles (FTCs), drying-wetting cycles (D-Ws), and salt erosion. To promote green and sustainable development of the construction industry, municipal solid waste incinerator bottom ash (MSWIBA) was adopted as a partial replacement for conventional fine aggregates in concretes. In this study, the coupled effects of the D-Ws and salt erosion (i.e., 5 % NaCl solution and 5 % Na2SO4 solution) were experimentally conducted to investigate the mechanical and microstructural properties of ordinary and MSWIBA concretes. The results showed that D-Ws had a negative effect on the mechanical properties of concretes. The depth and width of cracks in concretes increased with the D-Ws raised. During the D-Ws, the influence of salt solution on concretes could be divided into two stages. Initially, the filling effect of salt crystals was beneficial to the development of concrete strength. Subsequently, salt crystals accumulated in concretes caused cracks, and accelerated the deterioration of concrete specimens. Meanwhile, sodium sulphate reacted with hydration products in concretes to produce some expansive substances, the evident diffraction peaks of expansive substances (e.g., gypsum and ettringite) had been clearly observed after D-Ws. Thus, the damage effect of 5 % Na2SO4 solution (SS) to concrete structure was more serious than that of water (WT) and 5 % NaCl solution (CS). Furthermore, the total porosity of the concrete specimens generally decreased with the MSWIBA substitution rate increased. There was an optimal MSWIBA content for concretes to obtain the excellent mechanical and microstructural properties. In detail, when the substitution rate of MSWIBA was between 0 % and 33.0 %, it had an excellent effect on improving the pore structure of concretes. Specifically, the compressive strength of concretes was larger than 35.0 MPa when the substitution rate of MSWIBA with natural river sand was between 24.8 % and 57.8 %, whereas the substitution rate of MSWIBA should not exceed 33.0 % exposed to D-Ws. This study could provide a significant reference for the sustainable development of concretes in cold and saline soil areas, as well optimization and innovation usage of MSWIBA.

Investigation of the macro performance and mechanism of biochar modified ultra-high performance concrete

Ultra-high performance concrete (UHPC), an extraordinary category of cementitious composites, showcases unparalleled mechanical and durability properties. Given the current disparity in carbon levels and the environmental hazards associated with cement production, various types of biochar materials have been incorporated into cement composites. This approach offers a mutually advantageous solution, effectively reducing CO2 emissions while simultaneously preserving natural resources. This study aims to evaluate the use of palm shells, a waste biomass, as a substitute for aggregate in the UHPC matrix. The investigation focused on replacing 1–40 % of sand, specifically considering apricot, date, and peach shells biochar at an 8 % replacement. A comprehensive analysis was carried out on a total of 12 combinations, encompassing a control group. For biochar-mortar admixtures, a decrease in workability and density were observed. Replacing 1 % of sand with biochar in UHPC mortar improved compressive strength, but increasing biochar dosage weakened it. Biochar-mortar was demonstrated a dual impact on drying shrinkage. Mixtures with higher biochar dosages showed a slight increase in permeability. Incorporating 1 % biochar into UHPC led to a slightly lower electrical flux value. SEM images were obtained, highlighting the compact morphological structure seen in both the control and the 1 % biochar mortar. MIP test showed nearly 1.6 times increase in the 2-dimensional porosity, from 10.49 % (control) to 16.83 % for sample which had 30 % biochar. Based on the results obtained, it could be concluded that biochar possesses the capability, which enhances the properties of UHPC mortar when used as a partial replacement for conventional fine aggregate in minor fractions.

Investigating the mechanical and physical properties of lightweight geopolymer concrete

Using waste materials and by-products from various building sectors is gaining popularity because natural resources are quickly depleting. Geopolymer concrete is made from by-product material and is a relatively new environmental material that does not require the presence of ordinary Portland cement as a binder. This study involves producing lightweight geopolymer concretes using a slag binder and replacing the conventional fine and coarse aggregates with two types of locally available lightweight aggregate (thermostone and montmorillonite). Several sequential steps were used to process the aggregates, along with a series of tests conducted to evaluate the concrete properties in different states. The fresh state test includes the slump test, while the hardened concrete tests involve compressive strength, flexural strength, density, thermal conductivity, and water absorption. This study reveals the suitability of lightweight concrete mixtures for various constructional applications. The most reliable mixture was the GMM, which consisted of coarse montmorillonite (5–25 mm) and fine montmorillonite aggregates. This mixture exhibited the highest compressive strength of 23.3 MPa, a flexural strength of 3.25 MPa compared to other LWGC mixtures, and a low density of 1785 kg/m3. The GMM density was 23.97% lower than the reference mixture, whereas the thermal insulation significantly improved by 65.58%. Consequently, this improvement was evident in the thermal conductivity coefficient, which measured as approximately 0.349 W/m.K. In addition, the GTT mixture containing thermostone aggregate (5-25 mm) yielded the most optimal thermal insulation and lowest density of 0.267 W/m.K and 1552 kg/m3, respectively. In general, the strength and density of the LWGC mixtures in this study meet the requirements of lightweight structural applications.

Susceptibility to moisture damage in asphalt mixes with blast furnace dust as aggregate

One of the ongoing challenges in engineering is mitigating the degradation of road infrastructure caused by water in asphalt mixes. This study aims to assess the impact of blast furnace dust, a byproduct of the steel manufacturing process, on moisture-induced damage in asphalt mixes. Three asphalt mixes were developed following the Marshall methodology: one comprising conventional crushed aggregates, while the others substituted 50% and 100% of the conventional fine aggregate with blast furnace dust. Material characterization procedures and chemical analysis of the blast furnace dust were conducted. Once compliance with the specified material requirements was verified and analyzed, water susceptibility was evaluated through an indirect tensile test across various void content levels. Similarly, leveraging the Superpave gyratory compactor, several compaction indices were determined to estimate the compaction behavior of each mix. Based on the findings, the inclusion of blast furnace dust in an asphalt mix proved satisfactory due to its contributions in enhancing tensile strength, consequently leading to a reduction in moisture-induced damage within the asphalt mix, as well as exhibiting improved compaction behavior. Additionally, this utilization contributed to diminishing the environmental impact linked to the steel production process, where substantial quantities of this residue accumulate.

Study on Replacement of Fine Aggregate with Light Weighted Super Absorbent Material in Internal Curing Concrete

Abstract: The process by which concrete gradually acquires hardened qualities because of cement's continuous hydration in the presence of enough heat and water is known as "curing." In order to preserve concrete and get the desired results for concrete structures—that is, sufficient concrete strength, durability, and dimensional stability curing becomes necessary. Water is becoming a more scarce resource by the day, so research into ways to save water when creating concrete and building is desperately needed. In order for concrete to acquire the desired qualities in its early phases, it must be cured, or kept at a suitable moisture content. Good curing, however, is frequently impractical. Concrete's microstructure and pore structure are developed by curing, which enhances the material's performance and longevity. Although they cause a decrease in the strength of the concrete, lightweight particles can enable internal curing (IC) in concrete and lessen autogenously shrinkage and accompanying cracking. In order to determine the impact of internal curing using recycled materials, an experiment was carried out. Sawdust (SD), granite fines (GF), and powdered recycled clay (PRC) was used in part place of conventional fine aggregates.

Thermal and mechanical properties of a sustainable bio-flax fibre-based lightweight aggregate concrete

A novel lightweight aggregate concrete (LWAC) or lightweight concrete (LWC) is developed using expanded perlite powder and lightweight expanded clay aggregate as a replacement for conventional fine and coarse aggregates, respectively. Furthermore, the natural plant-based flax fibre in treated form was added to the LWC mix at three different volume fractions. The mechanical and thermal characterisation of LWC was carried out using the compressive strength test, split tensile test, modulus of rupture, thermal conductivity and thermal resistance test. Moreover, the microstructural and durability properties were obtained using scanning electron microscopy/energy dispersive X-ray spectrum analysis, rapid chloride penetration test, sorptivity test and water absorption test. Test results reveal that the addition of 2.0% flax fibre resulted in improved mechanical, thermal and durability properties when compared to LWC with no fibres. Moreover, the microstructural analysis using SEM revealed the formation of ettringite which is responsible for the strength development in the LWAC mix.

Study On Effect Of Marble Powder And Waste Foundry Sand As Fine Aggregates On The Properties Of Metakaolin-Cement Concrete

To bring an challenging and acceptable change in construction industry, upcoming graduates have to be much aware of alternate materials to be used in conventional concrete with improved performances and this study can be an encouraging approach to them. Many research studies have investigated the possible use of industrial by-products such as fly ash from thermal power plants, red mud from aluminium manufacturing industry, copper slag from copper smelting industry, GGBS from steel industry, and waste foundry sand from metal casting industries in cement concrete production. Here, it is investigated on the possibility of utilizing two industrial by-products in the production of concrete for achieving sustainable development. Metakaolin is used for replacing a specific percentage of cement, and waste marble powder and waste foundry sand are used to replace different percentages of conventional fine aggregates (sand) for producing a sustainable concrete. It is observed from the results that properties of cement concrete are influenced by the percentage content of metakaolin, waste marble powder and waste foundry sand.

Sustainable utilization of industrial by-products spent foundry sand and cement kiln dust in controlled low strength materials (CLSM)

In the present study, industrial by-products, spent foundry sand (SFS) and cement kiln dust (CKD) were used for developing controlled low strength materials (CLSM) and their various fresh and hardened state properties were examined. Embedded energy (EE), Embedded carbon dioxide (ECO2) as well as leachate toxicity of CLSM were also evaluated. Conventional fine aggregates were completely replaced by SFS; while CKD replaced cement at 0%, 25%, 50%, 75% and 100% levels; with the binder to aggregate ratio as 1:10. All the CLSM mixes were obtained while maintaining the flowability at around 250 mm. Addition of CKD increased flow and bleeding, delayed setting time and reduced compressive strength. The findings also indicate that SFS with even 100% CKD can be successfully utilized to prepare excavatable, eco-friendly and sustainable CLSM with bearing resistance equivalent to well compacted sands, suitable for general purpose backfill and utility trench filling. Mix with 75% CKD and 100% SFS as the only fine aggregate proved most suited from most of the aspects of a practical CLSM. All the proposed CLSM mixes were found to be environment friendly w.r.t leachate toxicity, low EE and ECO2. The study offers CLSM as an important alternative for the sustainable utilization of by-products in large quantities.

Utilizing Pulverized Glass as a Partial Replacement for Fine Aggregates in Cement Mortar

Mortar plays a pivotal role in the construction industry, underscoring the significance of comprehending its quality and the intricate interplay of its mixture in shaping performance outcomes. The utilization of waste glass as an innovative alternative to conventional fine aggregates in mortar mixtures is instrumental in enhancing structural safety. In light of this, the present study is dedicated to investigating the efficacy of waste glass incorporation in bolstering both compressive and flexural strength. This inquiry delves into the intrinsic qualities and strength attributes of concrete mortars, scrutinizing the influence of pulverized waste glass content. The range of powdered waste glass inclusions encompasses 0%, 10%, 15%, 20%, 25%, 30%, 50%, and 60% by weight in relation to the sand component of the mortar mixture. The experimental design involves the fabrication of a total of 72 mortar cubes, where 48 specimens are earmarked for conducting assessments of compressive and flexural strength. Compressive and flexural strength evaluations are conducted on the mortar samples after 7, 14, and 28 days of both moist and water curing protocols. The outcomes of these tests unveil the effectiveness of incorporating powdered waste glass as an aggregate within mortar mixtures, particularly at the 25% replacement mark. Intriguingly, the investigation highlights that concrete mortars imbued with 25% waste glass content exhibit superior strength in comparison to the other examined samples. Additionally, the study underscores that the strength outcomes for replacements of 25% and 10% successfully meet the prescribed strength requirements for cement mortar outlined in accordance with ASTM standards

Mechanism of macro- and microscopic performance of cement mortars influenced by municipal solid waste incineration bottom ash as sand substitution

With growing construction work, natural sand has turned out an endangered resource for building materials, leading to a research hotspot for alternative materials as natural sand substitutes. In this paper, we investigated the effect of municipal solid waste incineration (MSWI) bottom ash replacing natural sand on macro- and microscopic performance of cement-based materials after wet treatment. The viability of bottom ash in the mortar was explored instead of conventional fine aggregates. The fluidity, flexural strength, and compressive strength of different water-cement ratios in the mortar with substitution of 0%, 25%, 50%, and 75% were investigated by using the macro-experimental method. We examined the components and micro-morphology of hydration products by using thermogravimetry–differential scanning calorimetry (TG-DSC), X-ray diffraction (XRD), and scanning electron microscopy (SEM). The results demonstrated that a large substitution amount slightly effects the strength of cement mortar, while the early strength became stronger with the increase of the substitution rate. Notably, MSWI bottom ash showed a certain pozzolanic activity, which reduces the formation of Ca(OH)2 and can improve the early strength of the mortar. Additionally, the leaching concentrations of heavy metals (Cu, Zn, Pb, Cr, etc) in the mortars containing bottom ash were all less than the identification value of solid waste leaching toxicity. The carried out research confirmed that MSWI bottom ash can successfully replace conventional sand as building materials. The proposed work enables the reuse of MSWI bottom ash and also provides a reliable and effective method for solving the shortage of conventional aggregate resources.

Use of Blast Furnace Dust in the Production of Asphalt Concrete for Pavements, Performance and Environmental Contribution

This study analyzed the possible use of a residue from the steel industry, blast furnace dust, as aggregate in asphalt mixtures for pavements, as a possible solution to the problems of generation and accumulation of industrial waste in the production of steel, as well as the exploitation of non-renewable materials for infrastructure construction. In the production of steel, solid residues such as slag and blast furnace dust are generated, which become industrial waste. Another found issue in pavement construction is the exploitation and use of stone materials are necessary. Two test states were selected to achieve the established objective where blast furnace dust totally (100%) or partially (50%) replaced the conventional fine aggregate in an asphalt mixture at the laboratory. The applied methodology consisted of four stages: establishing the properties of the materials, determining the composition of the blast furnace dust, designing each of the mixtures using the Ramcodes methodology, and finally performing performance tests such as dynamic modulus and fatigue laws. The results show an acceptable behavior of the blast furnace dust and allow to define that the use of this residue is technically feasible in manufacturing asphalt mixtures for pavements.

Impact analysis of ceramic tile powder aggregates on self-compacting concrete

Waste ceramic tile (CT) powders are used to improve the workability, mechanical properties, and durability of self-compacting concrete (SCC). The waste CT powder is prepared by mixing construction tiles, sanitary fittings, and electrical insulators, with different weight percentages mixed into the SCC. Experiments have been conducted to evaluate the workability, mechanical, and durability of SCC. The optimum compressive, flexural, and tensile strengths were predicted to be 52.5 MPa, 8.5 MPa, and 7.8 MPa. SCC’s durability and workability characteristics are achieved by mixing 50% CT powder, which increases interlocking properties and meets EFNARC standards. It is concluded that CT powder can be substituted for conventional fine aggregate in concrete, increasing compressive, flexural, and split tensile strengths by 12.5%, 9.33%, and 28.76% compared to conventional SCC. The 50% CT powder mixed SCC is the optimum value for achieving optimal mechanical, durability, and workability characteristics. Samples of 50% CT powder-mixed SCC with 7, 28, and 90 days of curing processes and microstructure are also illustrated.

Investigation of the effect of substituting conventional fine aggregate with PCB powder on concrete strength using artificial neural network

Investigation of the effect of substituting conventional fine aggregate with PCB powder on concrete strength using artificial neural network

Mechanical, durability, and microstructural properties of mortars containing spent mushroom substrate as partial fine aggregate replacement.

Replacing conventional fine aggregates with spent mushroom substrate (SMS) is aimed at developing a sustainable lightweight masonry mortar. It is also an alternative solution for the current improper mushroom waste disposals. Density, workability, compressive strength, specific strength, flexural strength, ultrasonic pulse velocity, water absorption, sorptivity, and equivalent CO2 emission in relation to sand reduction in mortars containing 2.5-15.0% (by volume) SMS passing through a 4.75-mm sieve were investigated. As the percentages of replacement increased from 2.5 to 15.0%, the density of the SMS mortar reduced up to 34.8%, with corresponding compressive strengths of 24.96 to 3.37 MPa. Mixes with up to 12.5% SMS met the minimum compressive and flexural strengths as stated in the ASTM C129 standard. In addition, the equivalent CO2 emission of the mixes reduced 15.09% as the SMS content increased while cost-effectiveness increases up to 98.15% until 7.5% SMS replacement. In conclusion, the use of SMS as fine aggregates up to 12.5% is a viable mix design strategy for producing sustainable lightweight mortar with a lower carbon emission.

Performance of Cement–Fly Ash Masonry Mortar with Sand from Mine Overburden as an Environment-Friendly Alternative to Conventional Fine Aggregate

Abstract There is an increasing demand for fine aggregate for use in concrete and mortar. In this study, sand extracted from mine overburden from two locations through the wet-sieving process was used as alternative fine aggregate in mortar. The behavior has been benchmarked with mortar using conventional river sand and coarse and fine sand obtained from crushed stone. Combination mortar with ordinary portland cement and Class C fly ash was used as a binder. The sand-to-binder ratio was fixed as 3, as per ASTM C270-19ae1, Standard Specification for Mortar for Unit Masonry, whereas the fly ash–to–cement ratio was varied from 0.75 to 3. The water required to achieve a constant flow value of 110 ± 5 % was determined. The water retention of fresh mortar and dry density, compressive strength, and drying shrinkage of hardened mortar were determined. Mortar mixtures with sand from mine overburden with a fineness modulus of 2.36 conformed to the water retention requirement of ASTM C91/C91M-18, Standard Specification for Masonry Cement, whereas very fine sand did not satisfy. Masonry mortar with different mixture proportions and fineness modulus of fine aggregate resulted in a range of compressive strengths, satisfying a wide range of mortar designations as per ASTM C270-19ae1, BS EN 998-2, Specification for Mortar for Masonry - Part 2, and IS 2250, Code of Practice for Preparation and Use of Masonry Mortars. For mortar with a fine aggregate of different origins (river sand, crushed stone coarse sand, sand from overburden with fineness modulus 2.67, 3.01, and 2.36, respectively), a marginal variation in drying shrinkage across strength was observed. The maximum drying shrinkage of the higher fly ash–to–cement ratio of the mixture with finer sand was 1,600 microstrain.

Thermal performance of cement-leca composites for 3D printing

This work aimed to evaluate the influence conventional fine aggregate substitution by LECA (light expanded clay aggregate) evaluating the physical and mechanical properties of lightweight cement-based composites for 3D printing. The mixtures were formulated using a 22 central composite rotatable design (CCRD). The independent factors were the substitution content of sand and the aggregate-to-binder ratio. The results showed that the replacement of sand by LECA increased the thermal insulation without compromising important structural properties such as mechanical strength and porosity. The thermal behavior of the composites was modeled and an equation dependent only on the substitution content was found.

Design of Structural Concrete with Bone China Fine Aggregate Using Statistical Approach

In this rapidly industrializing world, recycling materials for construction is crucial for protecting natural resources and promoting sustainable human growth. It should be carefully considered because using the waste in the structural concrete is cost-effective but it is also constrained due to its declining qualities. Bone China waste (BCW) possesses pozzolanic properties and it was occasionally used in concrete by a few researchers. Therefore, in the current investigation, the workability, compressive, split tensile, and flexure strengths of the fresh and hardened characteristics are first determined. 0%, 20%, 40%, 60%, 80%, and 100 percent of (BCW) were utilized to replace natural fine aggregate (sand). The experiment’s findings demonstrate that every percentage of BCW replacement yields the desired characteristic strength, a mix with 60% BCW yielding the highest strength value. Furthermore, it was discovered that utilizing fine bone China instead of conventional fine aggregate in concrete increased the compressive, split tensile, and flexure strength. Through traditional laboratory experiments, a valid criterion for choosing an ideal mix combination of BCW as fine aggregate in concrete is quite laborious and time-consuming. As a result, the statistical models were presented based on the laboratory-tested compressive strength data for concrete including varying amounts of bone China waste as fine aggregate, which show resilience and normality when assessed using fundamental statistical techniques. Finally, a good agreement was found between the created models and the experimental results as well as with proven existing models. These models can forecast the compressive, flexural, and split tensile strengths of concrete when combined with bone China fine aggregates or any other type of fine waste. With this framework, one may examine the same factors as the study and make sure that concrete has the maximum strength and sustainability. An improved microstructure of the concrete was observed which exhibits fewer porosity and cracks when fine BCW was used in place of sand.

Iron Ore Tailings as Partial Replacement for Fine Aggregate in Concrete Production – Review

Normal River sand is one of the major components of concrete, generally termed fine aggregate. A large volume of sand is needed annually for construction work globally. Mining or extraction of sand from the river bed, ocean beds, beaches, and inland dunes is accompanied by several problems such as; lowering of the water table, sinking of bridge piers and erosion of river bed and instability of river bed on the environment, etc. To decrease these environmental impacts and the cost of conventional fine aggregates, alternative materials like mining waste have been studied by several researchers to replace partially fine aggregates in concrete production. Iron ore tailings (IOT) are one of the mining wastes obtained from the beneficiation process of iron ore concentrates. This paper presents an overview of the work carried out on the use of IOT as a partial replacement of fine aggregate in concrete and its effects on the workability, mechanical, and durability properties of concrete.