Mechanical Properties Of Concrete Research Articles

Mechanical and durability properties of polymer fiber reinforced one-part foam geopolymer concrete: A sustainable strategy for the recycling of waste steel slag aggregate and fly ash

This paper assesses the feasibility of geopolymers (GPs) for use as lightweight foamed concrete, a crucial step towards reducing the carbon footprint and conserving natural resources. A powder activator (i.e., sodium metasilicate) less harmful to the environment was used to activate the fly ash-based GPs, while the limestone aggregates were gradually replaced by up to 100 % waste slag materials to conserve natural resources. Polypropylene fibers were incorporated at high dosage rates of 1 % or 2 %, by volume, to reduce the concrete density and improve its durability properties. Tested properties include flow, density, water absorption, porosity, thermal conductivity, mechanical strengths, drying shrinkage, and resistance to sulfate attack, freeze/thaw cycles, and elevated temperature. Results showed that the concrete mechanical properties improved when the limestone aggregate was replaced by slag materials, but the density and thermal conductivity were slightly curtailed at higher addition rates. The use of polypropylene fibers proved efficient to improve the resistance to freeze/thaw cycles, drying shrinkage, and expansion due to sulphate attack. Such data can help sustain the green building industry development by reducing the carbon footprint and conserving natural resources in foamed concrete applications.

Exploring Performance of Using SCM Concrete: Investigating Impacts Shifting along Concrete Supply Chain and Construction

Concrete is one of the most used building materials globally, leading to a large amount of greenhouse gas (GHG) emissions. Using supplementary cementitious materials (SCM) as replacements for cement in concrete provides an effective way to reduce GHG emissions. However, quantifying the construction performance of using SCM concrete is hard because of complex interactions between concrete’s mechanical properties and construction characteristics, like local energy supply, surrounding temperature and construction plans, which leads to only the fragmental performance of using SCM concrete being explored in previous studies. There still lacks an effective way to quantify the comprehensive performance and provide decision support for contractors about how to use SCM concrete. To deal with the gap, this research proposes a Collection–Simulation–Calculation–Decision (CSCD) method to analyze the complex interactions between concrete and construction, and to quantify the performance of the supply chain–construction when using SCM. A case study is also conducted to demonstrate the effectiveness of the proposed method. The results show that the proposed method is effective in quantifying the performance of using SCM concrete in construction and providing decision support for construction decision makers. A scenario analysis is also conducted to demonstrate the effectiveness of the proposed method in different project characteristics, including the global warming potential (GWP) factors for different construction sites, seasonal temperature changes and different construction plans. The proposed method is an effective tool to quantify the construction performance of using SCM concrete considering complex interactions between concrete mechanical properties and construction characteristics. The results of the research can assist construction decision makers to make decisions about using SCM concrete by comprehensively understanding the impacts shifting along the concrete supply chain and construction.

Predictive Analysis of Ceramic Waste Modified Concrete Properties Ising ANN and Linear Regression Algorithm

In this study, concrete modified with ceramic waste was modelled. The ceramic waste percentage ranged from 2.5% to 5% to 10% to 12.5% to 15% to 17.5% to 20%. Modelling was done for the concrete's tensile strength and compressive strength. Regression modelling and artificial neural networks were used as prediction methods for concrete strength. The models developed in this study to predict the mechanical properties of concrete were evaluated using Mean absolute error, coefficient of determination and root mean square error. The R2 value for the ANN model was determined to be 0.97, compared to 0.95 for the linear regression model. For the one-week, two-week, and four-week prediction models, RMSE values were 1.1 MPa, 1.15 MPa, and 1.05 MPa for the ANN model for one-week, two-week and four-week, respectively, while the linear regression model displayed the RMSE values of 1.08 MPa, 1.22 MPa, and 1.25 MPa. The R2 values for ANN and LR models were estimated to be 0.87 and 0.7, respectively, for predicting split tensile strength. This study will conclude that the artificial neural network model has high accuracy. It can be employed in modelling the mechanical properties of ceramic-modified concrete.

Experimental Study on Properties of Graphene and Hollow Glass Powder-Added Ultra-High Strength Concrete

A new ultra-high strength concrete, in which oxidized graphene nanoplatelet (GO) and hollow glass powder (HGP) are added, has been developed by authors. This paper presents the material properties of the concrete such as workability, compressive and tensile strengths, internal micro structure (SEM and MIP) as well as air-tightness which was tested using an equipment developed in this study. Test results show that workability and tensile strength significantly increase by a small addition of HGP, and that cGO (GO product of company c) and HGP are well dispersed without agglomeration effect, resulting in more than 20% of reduction in porosity. It is also observed that air-tightness increases by 40% compared with conventional ultra-high strength concrete due to reduction in porosity; thus, new ultra-high strength concrete is anticipated to be effectively used for structures that requires air-tightness such as hyperloop tube. Consequently, it was observed that the workability and mechanical properties of UHSC were increased when cGO and HGP were used instead of silica fume (SF), and authors believe that utilization of new material would contribute to the change in manufacturing method and increase in mechanical properties of concrete.

Alternative concrete aggregates - Review of physical and mechanical properties and successful applications

Concrete is one of the most widely used construction materials, yet its production is associated with significant environmental impacts. One approach to mitigate such impacts is to use alternative aggregates. However, the limited knowledge about the availability and benefits of these unconventional materials, as well as concerns about their quality and performance, have hindered their adoption. This paper aims to analyse the potential benefits and limitations of using alternative aggregates in concrete by reviewing examples from three primary sources: construction and demolition waste (CDW), end-of-life materials (i.e., tyre rubber, glass, and plastic), and forest and agricultural waste (i.e., rice husk, wood, and hemp). First, the main sources and treatment needs are analysed. Then, a comprehensive macro analysis is provided on the physical and mechanical properties of concrete materials, discussing the results in terms of the aggregate nature and substitution ranges. The collected experimental data are also compared with estimations based on different models from two published codes, suggesting that more specific design-oriented models need to be developed to relate concrete's physical and mechanical properties using different waste-type aggregate replacements. Selected data analyses are presented to help the readers obtain the optimum content for specific structural or non-structural applications. Examples of successful application of alternative aggregates in construction projects and products are also provided and discussed.

Investigation of the Tensile Strength of Sea Sand Concrete Against the Compressive Strength of the Plan

The availability of sea sand on the beach of Ujung Tape Pinrang is in very large quantities that can be used as materials in making concrete. The purpose of the study is to analyze the characteristics of beach sand, compressive strength and tensile strength produced. An experimental research method in the Civil Engineering Laboratory, University of Muhammadiyah Parepare with a treatment system for ordinary water immersion and analysis of the characteristics of concrete mechanical properties using a compression machine test. The results of the study at the maintenance age of 28 days with a planned compressive strength of 20 MPa produced a compressive strength of 28.29 MPa and a tensile strength of 7.78 MPa, a planned compressive strength of 24 MPa resulted in a compressive strength of 29.98 MPa and a tensile strength of 8.22 MPa, and a planned compressive strength of 28 MPa produces a compressive strength of 31.40 MPa and a tensile strength of 8.44 MPa. The results of the study on compressive strength and tensile strength showed an increase in each increase in planned compressive strength.

Study on phase change materials integration in concrete: Form-stable PCM and direct addition

As the economy continues to develop, building energy consumption rises, necessitating sustainable solutions. Concrete, a pivotal building material, assumes a vital role in this context. To address the challenge of escalating energy consumption and environmental impact, this study studied the integration of phase change materials (PCMs) into concrete by two methods. Recycled aggregates serve as form-stable mediums for PCM absorption, while direct addition methods incorporate 7.5 % and 15 % free liquid PCM by volume of river sand. Six concrete mixtures underwent comprehensive evaluation encompassing workability, density, water absorption by immersion, compressive strength, flexural strength, chloride ion penetration, freeze-thaw cycling tests, and carbonation. The results reveal a decrease in concrete density and mechanical properties with increasing PCM content. Nevertheless, notable enhancements in chloride ion penetration resistance, reaching up to 18.5 % with free PCM incorporation, and zero carbonation depth were observed. These results underscore the potential of PCM-concrete composites in harmonizing energy efficiency and structural integrity, offering a sustainable alternative to fossil fuel-based air conditioning systems and with great potential from the point of view of the durability of the structures.

Polypropylene waste plastic fiber morphology as an influencing factor on the performance and durability of concrete: Experimental investigation, soft-computing modeling, and economic analysis

The increasing waste of plastic masses raises the danger alarm due to its adverse impacts on people and the natural environment. Hence, serious attempts should be made to manage this non-biodegradable waste for practical, sustainable, and sufficient uses, such as in construction. This research discusses experimentally the possibility of improving the behavior of concrete reinforced with waste plastic fibers (WPFs) from food trays by examining the effect of fibers morphology on concrete's mechanical properties and durability. This concept was intensively studied for steel fibers but rarely for WPFs. A 0.6 percentage of 30 mm long straight, spiral, and channel fibers were tested and compared. Compressive, tensile, and flexural strengths, impact resistance, water absorption, rapid chloride penetration tests, and microstructural analysis were conducted. The results revealed that the fibers shape influences the mechanical behavior along with the water absorption considerably, and that the spiral fibers exhibited superior performance compared to the other shapes. The mechanical properties of spiral fibers specimens have improved considerably compared to specimens of other shapes. However, the ion chloride penetration resistance did not witness any substantial improvement, and the brittle fracture of concrete did not change by using WPFs, despite the considerable increase of more than 66 % of the impact resistance of specimens with spiral fibers. According to the findings, spiral WPFs enhance concrete's behavior, making WPF implementation in concrete more efficient from an environmental and structural standpoint. Moreover, machine learning modeling and cost/benefit analysis were conducted in this work to better understand the WPF effect on concrete.

Study on the effect of polypropylene fiber shape and admixture on the mechanical properties of concrete

Study on the effect of polypropylene fiber shape and admixture on the mechanical properties of concrete

Sustainable Optimization of Thermal and Mechanical Properties in Concrete Using Natural Additives: A Molecular Approach

Este artículo explica la interacción molecular en el hormigón y su impacto en las propiedades mecánicas, centrándose específicamente en la resistencia y la transferencia de calor. Se hace hincapié en el papel fundamental de las interacciones moleculares en la configuración de las características macroscópicas del hormigón, en particular su resistencia a la compresión, a la tracción y a la flexión. El hormigón, compuesto por cemento, agua, áridos y aditivos, ve su comportamiento estructural intrincadamente influenciado por estas interacciones moleculares. Se preparó una muestra de 200 kg/cm2 con y sin aditivo (obtenido de Opuntia ficus – indica). Los resultados ponen de manifiesto un notable aumento de la velocidad del pulso ultrasónico con la incorporación de aditivos. Además, hay modificaciones perceptibles en la capacidad térmica, lo que subraya el impacto tangible de las interacciones moleculares. Las representaciones micrográficas retratan vívidamente la reducción de los espacios entre los componentes dentro del medio estudiado, estableciendo una correlación con las alteraciones en la velocidad del pulso ultrasónico y las propiedades térmicas asociadas a dicha compactación. Este estudio brinda conocimiento de las propiedades que son mejoradas y que impactan a la sostenibilidad del material, mediante el empleo de materiales naturales.

Enhancing bio-based concrete mechanical properties: a novel approach with composite sandwiches and confined cylinders

Enhancing bio-based concrete mechanical properties: a novel approach with composite sandwiches and confined cylinders

Исследование влияния СО2 на формирование наноразмерной структуры и физико-механические свойства бетона

Исследование влияния СО2 на формирование наноразмерной структуры и физико-механические свойства бетона

An Experimental Study on Mechanical Properties of Concrete by Partial Replacement of Cement with Graphene Oxide

Abstract: An essential building material, concrete is always changing for increased sustainability and performance. This study looks into the effects of replacing some of the cement in M60 grade concrete with graphene oxide. One amazing nanomaterial that is available in powder, sheets, flakes, and oxide form is graphene oxide. It has lately been used in the building industry and is robust, elastic, and lightweight. It has excellent qualities that are advantageous in the building industry. Adding graphene oxide to concrete composites improves binding strength to concrete structures, lowers permeability, and speeds up the pace of hydration. The concrete samples are tested for slump, split tensile strength, compressive strength, flexural strength, and durability after seven, twenty-eight, and fifty-six days. Graphene oxide concentrations in concrete compositions ranging from 0.5% to 2% by cement weight. The findings demonstrate that adding graphene oxide to concrete enhances its strength, with some mix compositions exceeding regular concrete. The mechanisms producing the strength increase are illuminated by the analysis of the experimental data, underscoring the potential of these additional components to enhance the durability as well as sustainability of concrete structures. These discoveries advance the field of construction material engineering by contributing to ongoing attempts to create high-performance and sustainable concrete compositions.

Evaluation of Energy Dissipated by Non-Sintered Hwangto Concrete after Exposure to Elevated Temperatures

To reduce CO<sub>2</sub> emissions, the construction industry is applying various mineral admixtures to reduce cement usage. This study evaluates the mechanical properties of non-sintered Hwangto concrete, which is an eco-friendly mineral admixture, after exposure to high temperature. The evaluation is performed for four variables: unit weight, compressive strength, stress-strain behavior, and dissipated energy, under six target temperatures ranging from room temperature to 700 °C. Experimental results show that non-sintered Hwangto degrades the mechanical properties of concrete at room temperature but exhibits better residual mechanical properties compared with cement after being exposed to high temperature.

QUALITY IMPROVEMENT EFFECTIVENESS OF ROAD SLABS PRODUCED USING MICROSILICA AND FIBER

Here we present the results of testing the concrete physical and mechanical properties for road slabs reinforced with bulk fiber, including polypropylene macro- and microfibers. We have analyzed the effect of the use of macrofibers and microfibers in the concrete composition. There was established the impact of low-modulus synthetic fibers on the characteristics of strength, density, water resistance and frost resistance of concrete for road pavement. It was established that polypropylene macrofibers impact on the physical and technical characteristics of concrete, increase compressive and bending strength, and polypropylene microfibers improve the structure of the cement component of concrete, optimize the pore space, increase the frost resistance and water resistance of concrete. It has been experimentally proved that owing to the combined use of various sized fiber fibers, it is possible to produce concrete that has good characteristics in strength, density and frost resistance. It was established that with the combined concrete fiber reinforcement with microsilica addition, we get the possibility of increasing bending strength up to 35%, frost resistance up to F375 and water resistance up to W14. The research results make it possible to recommend multi-dimensional polypropylene fibers for volumetric reinforcement and microsilica to create additional crystallization centers and reduce the pore space in the concrete body at road slabs manufacture.

Enhancing mechanical and radiation shielding properties of concrete with lead monoxide and granodiorite: Individual and synergistic effects at micro and nano particle scales

AbstractThis study investigates the individual and combined effects of micro and nano lead monoxide (PbO) and granodiorite (GD) on concrete's mechanical and radiation shielding properties. Both materials were partially substituted for cement at varying ratios. Additionally, mixtures with optimal radiation shielding performance were prepared to explore the synergy of combining them. The mentioned materials are used for the first time in an extensive study at the nano scale to investigate their impact on concrete's mechanical properties, microstructure, and gamma radiation attenuation. Two gamma ray sources of uranium (U238) and cesium (Cs137) were used measure the radiation attenuation coefficients for all designed concrete mixes. A simple methodology was followed to assess the concrete shields efficiency via utilizing portable handheld gamma‐ray spectrometer that offers two reading modes. Results indicated that increasing the ratio of PbO is directly proportional to the concrete ability to attenuate radiation, where the optimal individual replacement ratios were recorded at 5% for micro and nano particle sizes. At this ratio, the linear attenuation coefficient (μ) values were improved by 39.57% and 24.78% for the nano and micro PbO, respectively. Additionally, the optimal ratio for improving mechanical properties was at 3% and 2% for nano and micro PbO, while the higher ratios showed a decline in mechanical properties especially at 5% micro PbO with 7.02% reduction in the compressive strength value. Regarding GD powder, the optimal replacement ratios for improving concrete radiation shielding were consistent with those enhancing its mechanical properties at 4% and 7% in both nano and micro scales, respectively. The combined mixes further enhanced the overall concrete performance, especially its radiation shielding ability. Compared to the control mix, the compressive strength, tensile strength, and μ were increased by 25.7%, 16.2%, and 44.7% at the optimal mixture of 5% nano PbO + 4% nano GD.

MECHANICAL BEHAVIOR OF CONCRETE BY REPLACING FINE AGGREGATE WITH GROUND GLASS AND SAWDUST

Ground glass and sawdust are products that are commonly discarded, causing a negative impact on the environment; however, they can be reused in the construction sector; thus, the purpose of this research was to evaluate the mechanical properties of concrete by substituting ground glass and sawdust in proportion to the weight of fine aggregate. A total of 216 concrete samples were prepared for the evaluation of compressive strength, tensile strength, flexural strength, and modulus of elasticity, for which concrete samples formed a control group without any addition, and three experimental groups were formed by samples with substitution of ground glass in percentages of 10%, 20%, and 30%, and sawdust in percentages of 10%, 15%, and 30%. The analyzed results showed that the combination of substitution of 20% ground glass and 10% sawdust improved the mechanical properties of the concrete, increasing its value by 2.65% for compressive strength, 1.68% for flexural strength, and 6.51% for modulus of elasticity, corresponding to the design of f'c= 280 kg/cm². Likewise, there was a 3.18% decrease in the tensile strength test. Based on the above, it is concluded that the substitution of ground glass and sawdust contributes to a minimal improvement in the mechanical properties of the concrete.

Crack Behavior of Eccentrically Braced Frame Type-V with Ground Granulated Blast Furnace Slag

To make the structure stronger and stiffer, which is more susceptible to earthquake forces, a special mechanism is required to improve the structure's lateral stability. EBF-V with a horizontal link beam is a brace that can enhance structural performance by providing good stiffness and ductility. On the other hand, GGBFS, as a partial OPC replacement material, was applied to contribute to using more environmentally friendly materials. Besides offering a smaller carbon footprint, GGBFS also positively improves the mechanical properties of concrete. Thus, this study focuses on investigating the crack propagation pattern of reinforced concrete braced frames combined with 20% GGBFS in EBF-V with three variations of link beam element lengths of 0 cm (CBF), 15 cm (EBF-V-) and 25 cm (EBF-V-25). As a result, the CBF specimen showed the best seismic performance. In EBF specimens, there is an increase in the collapse mechanism to be more ductile. The link beam plays a role in making the crack pattern more focused. EBF-V-15 performs well under seismic loading with large lateral capacity and ductility. The cracks in the frame are evenly distributed, dominated by fine cracks, and symmetrical on both sides. This validates that GGBFS plays a good role in improving the frame performance with its pore-filling effect and pozzolanic reaction.

Effect of Corn Stover Ash Reinforced with Cabuya Fiber on the Mechanical Properties of Concrete

Currently, organic wastes are an environmental problem generating pollution, bad odors and accumulation of residues in northern Peru, among these products are corn stover and cabuya, predominant materials in the area. Therefore, this research focuses on determining the effect of optimum temperature and optimum percentage of corn stover ash (CSA) reinforced with different proportions of cabuya fiber (CF) on the mechanical properties of concrete. Two conventional designs of standard concrete called A and B (21 and 28 MPa) were made, to these designs were added percentages of CSA in 7%, 10%, 12% and 15% by substitution of the weight of cement to determine the optimum percentage, which was reinforced with percentages of cabuya fiber in 0.5%, 1%, 1.5% and 2% in volume of the concrete. The results showed that the optimum mix was A/B+7CSA, evidencing an improvement in compressive strength of 2.7% as opposed to the optimum CSA +CF hybrid mix, where it was observed that its mechanical properties of compressive strength, tensile strength, flexural strength and static modulus of elasticity decreased to 15.8%, 11.30%, 5.14% and 10.5%, respectively. It is concluded that corn stover ash reinforced with cabuya fiber does not positively influence the mechanical properties of concrete; however, it is an environmentally sustainable alternative to be used in non-structural concrete.

The Effect of Copper Tailings Sand on the Workability and Mechanical Properties of Concrete

The Effect of Copper Tailings Sand on the Workability and Mechanical Properties of Concrete