Properties Of High Strength Concrete Research Articles

Durability and ecological assessment of low-carbon high-strength concrete with short AR-glass fibers: Effects of high-volume of solid waste materials

The goal of this research is to improve the mechanical characteristics and durability of concrete while adhering to green and sustainable development principles. Portland cement (PC) was replaced with ceramic waste powder (CWP), glass powder (GP), and granite waste powder (GWP) to create the low-carbon, high-strength concrete (HSC). These materials were incorporated at 0–50% as a partial replacement of PC. The short alkali-resistant (AR-) glass fiber content was added by 1.0% of the PC content. The changes in strength, microstructure, pore structure, as well as ecological assessment of HSCs was investigated. Various experiments on the durability properties and elevated temperature resistance of HSC were performed. The experimental results show that mechanical properties of HSC with 10%GP and 20%GWP were maximally enhanced at 28d, while the mechanical properties of HSC with 50% of all wastes are decreased. It was found also that HSC containing CWP showed significant reductions in carbonation depth (up to 65.89% lower than the control mixture), especially at higher replacement levels. Furthermore, the increment in substitution level of CWP has found an increment in pore volume, resulting in a reduction in preliminary strength performance. It was observed that a 50% substitution level of GP and GWP reduced the water penetration depth by 47.71% and 65.7% compared to the control mixture, respectively. The residual strength after 600 °C exposure for 10%CWP, 10% GP, and 20% GWP retained about 34.10%, 32.32%, and 43.29%, respectively, from their original strength. XRD tests and SEM micrographs showed that adding 10%GP and 20%GWP improve the hydration reactions. Finally, environmental assessments revealed that incorporating CWP, GP, and GWP into HSC led to reduced costs, energy consumption, and carbon footprint.

Sustainable reuse of waste ceramic tiles powder and waste brick powder as a replacement for cement on green high strength concrete properties

Nowadays, reducing construction waste has grabbed the attention. As bricks and ceramic tiles represent more than 50% of the ceramic waste in many European countries. Thus, the recycling of this waste type is one of the most significant challenges within the paradigm of the circular economy. This paper investigated the impact of substitution levels of cement by waste ceramic powder (WCP) and waste brick powder (WBP) at 0%, 5%, 10% and 15%, on the HSC characteristics. The WBP and WCP materials were characterized in detail by laser granulometry, XRF and XRD measurements, followed by standard mixing, production, and curing of concrete samples. The experiments on dry density, modulus of elasticity, flexural strength, splitting tensile strength, compressive strength, resistance to sulfate attack, water absorption and ultrasonic pulse velocity were conducted to evaluate the hardened properties of concrete. It was demonstrated that the durability and strength of concrete containing WBP and WCP as partial replacements for cement are marginally inferior to those of the control sample. On the other hand, samples containing WBP had a lesser negative effect on HSC properties in comparison with samples containing WCP. However, employing a 5% WBP with 10% WCP mixture enhanced the characteristics of the HSC in comparison to samples containing various percentages of WCP individually. In addition, the microstructure analyses revealed that the addition of 10% WCP and 5%WBP to HSC specimens resulted in higher hydration products and a slightly denser concrete matrix compared to samples containing various percentages of WCP individually. Research findings indicate that a 15% substitution of cement with WCP or WBP illustrated an environmental benefit in concrete production due to a 13.1% reduction in specific energy consumption.

Potential usage of fly ash and nano silica in high-strength concrete: Laboratory experiment and application in rigid pavement

High-strength concrete (HSC) using supplementary cementitious material of 30% fly ash (FA) and various nano silica (NS) contents were investigated in this study. FA and NS are waste materials collected from local thermal plants and rice husk ash in Southern Vietnam, respectively. Different concentrations of NS at 0%, 0.5%, 1.0%, and 1.5% were incorporated into the base mixture in place of cement and FA. The water-to-binder ratio of 0.32 was constant for all the mixtures. Results indicated that the combination binder of cement, FA, and NS satisfied the setting time as pure cement binder. The slump test value was in the range of 30–40 mm by adjusting the superplasticzer. Mechanical properties of HSC were studied at various curing ages of 3, 7, 28, and 56 days, including compressive strength, flexural strength, elastic modulus, and abrasion resistance. Results indicated that 1% NS can be considered as optimum content for preparing an HSC mixture, which showed the best mechanical properties. Furthermore, a good correlation between compressive strength and flexural strength was obtained from the results. Finally, rigid pavement calculation revealed that the addition of 1% NS resulted in a reduction in the thickness of the concrete slab by 30 mm (around 10.7%) compared to non-NS concrete. These findings suggest that incorporating nano-silica into concrete can lead to thinner concrete slabs with improved performance characteristics.

The effect of particle sizes of steel slag as cement replacement in high strength concrete under elevated temperatures

This study investigates the impact of utilizing steel slag (SS) as a partial substitute for cement in high strength concrete (HSC) under high temperatures covering a range from 200 °C to 800 °C over a duration of 2 h. Two particle sizes of SS: 75 µm and 150 µm, were utilized as fine steel slag (FSS) and coarse steel slag (CSS). This study evaluates several physicochemical and compressive strengths of the HSC. After conducting the compressive strength, both residual compressive strength (RCS) and relative residual compressive strength (RRCS) were calculated. Scanning electron microscopy (SEM), Thermogravimetric analysis (TGA), and X-Ray Diffraction (XRD) analysis were carried out to analyze the physicochemical properties of HSC before and after subjected to elevated temperatures. The findings indicate an increase in the RCS of all specimens up to 400 °C. The replacement of FSS for cement enhances the compressive strength of HSC at ambient temperature, and FSS performs better than CSS up to 200 °C. However, beyond 400 °C, CSS exhibits a superior RRCS compared to FSS. XRD analysis confirms mineralogical changes in the HSC after exposure to fire, including the decomposition of C-S-H gel and the conversion of calcium hydroxide into calcium carbonate. The present study suggests that incorporating CSS in HSC has the potential to enhance its performance under high temperature conditions.

Suitability of marble powders in production of high strength concrete

A tremendous amount of non-biodegradable waste is created during mining and processing tasks of layered stones like marble. Over time, this has become a global problem because it harms the environment in multiple ways. Hence, it is necessary to find an alternate way to securely dispose and reuse marble wastes. The construction sector is one of the significant consumers of natural resources for the production of material binders and aggregates. As a result, in recent years, number of researchers have carried out studies in which various kinds of marble waste have been incorporated into concrete with the intention of substituting either cement or aggregates or both. This paper presents the effect of two locally sourced waste marble powders Kadapa marble powder (KMP) and Bethamcherla marble powder (BMP) as partial replacement of cement on mechanical and durability properties of high strength concrete (HSC). Their effect at different replacement levels in HSC is evaluated in compressive, indirect tensile and flexural strengths, elastic modulus, chloride penetration resistance and freeze–thaw durability properties. Micro-structural investigation is also conducted to evaluate their impact on the matrix of HSC containing waste marble powders as additional cementitious materials. Results show that the HSC consisting of KMP and BMP content of 10% and 15%, respectively exhibited higher mechanical and durability properties than the control HSC. Micro-structural investigation also supports this finding. It can be concluded that the use of marble powders as partial replacement of cement does not have any adverse impact on the properties of concrete. The use of KMP and BMP reduces the vast amount of energy required to produce cement, cost and time with reduction in environmental hazards.

The Effects of Recycled Carbon Fibers on the Mechanical Properties of High-Strength Concrete and Its Resilience to Impact

The Effects of Recycled Carbon Fibers on the Mechanical Properties of High-Strength Concrete and Its Resilience to Impact

Experimental Analysis of High-Strength Concrete Using Granite Aggregates

The present study investigates the effect of incorporating metakaolin and silica fumes in the production of high-strength concrete along with partial replacement of coarse granite aggregates in the high-strength concrete. The higher compressive strength, refined microstructure, and decreased permeability of high-strength concrete are some of the properties responsible for its trending use in the modern construction industry. The main purpose of this research is to evaluate the effect of the replacement of coarse granite aggregates with natural aggregates on the mechanical and durability properties of high-strength concrete. For understanding the effect of metakaolin, silica fume, and granite aggregates on the properties of high-strength concrete, various specimens such as cubes, cylinders, and cylindrical discs were cast and tested after 7, 14, and 28 days of curing. Various concrete mixes were prepared by adding silica fume at 5%, 7.5%, and 10% and metakaolin at 5%, 7.5%, 10%, 12.5%, and 15% in concrete production. Furthermore, High-strength concrete mixes were also prepared by replacing natural coarse aggregates with granite coarse aggregates by 25%, 50%, 75%, and 100% to study the effect of replacement percentage on the concrete properties. Test results indicated that the compressive strength and split tensile strength of the concrete mix increased with the increase in the replacement percentage of granite aggregates, with the highest strength seen at complete replacement with granite aggregate due to the enhanced compressive strength of such aggregates in comparison with the natural coarse aggregates. In various mixes cast using metakaolin and silica fume, the highest compressive strength was seen in a mix containing 10% metakaolin and 7.5% silica fume, and results of other mixes indicated that the use of silica fume and metakaolin are viable options for high-strength concrete production in our experimental study.

Behaviour of FRP-ECC-HSC composite stub columns under axial compression: Experimental and mathematical approach

The composite stub column composed of fiber-reinforced polymer (FRP), Eco engineered cementitious composite (ECC), and high-strength concrete (HSC) core is experimentally investigated in this study. The ductile performance of HSC-FRP is enhanced by proving an ECC ring of 30 mm thickness as sandwich layer between HSC and FRP. During experimentation the premature failure of the FRP-HSC column is observed at the initial phase, which exhibits brittle nature of the column. The material properties of FRP, ECC, and HSC were characterized. The performance of composite columns was observed with four FEH (FRP-ECC-HSC) columns, four HE (HSC-ECC) columns, and two FH (FRP-HSC) columns. The parameters such as uniform hoop strain distribution, ultimate load-carrying capacity, axial and hoop strain, and confining efficiency of the FRP were investigated to understand the behaviour of composite columns. From results, the ultimate load-carrying capacity of FH columns was 15.56 % higher than the FEH columns. The FEH columns showed the enhanced confining efficiency of FRP and 21% increase in uniform hoop strain distribution than the FH columns. The hoop strain capacity of FEH columns were increased twice the times of FH columns, which indicates the increased ductile behaviour of the FEH columns. In addition, experimental results of composite columns were highly correlated with the existing theoretical equation from literatures

A Parametric Study on Fibre Reinforced Concrete

Abstract: The investigation is focused to study the effect of various types of fibres on compressive strength, split tensile strength and flexural strength of High strength concrete. The water to cementitious material ratio considered for the study of High strength concrete was 0.25. The content of silica fume and fly ash in every mix was 5% and 10% by the weight of cementitious material. Two types of fibres considered for the study include, Polypropylene Fibres (PF) and Flat Steel Fibres (FSF). Dosage of fibre was varied from 0.5% to 4% at an interval of 0.5% by weight of cementitious material. Type of cement, fine aggregate, coarse aggregate, type of Superplasticizer and its dosage are kept constant in every mix. The use of High Strength Concrete (HSC) is increased now a days. It is observed that HSC relatively brittle material. Fibres are added to improve its ductility. Experimental study is carried out to assess mechanical properties of high strength concrete (HSC) of grade M70.

The combined effect of steel fiber and MgO on the deformation and mechanical properties of high-strength concrete

Shrinkage cracking of concrete is one of the main problems affecting the durability of high-strength concrete. One of the main measures to solve this problem is to use expansion agents to compensate for the shrinkage of concrete. But on the other hand, excess expansion, while compensating for shrinkage, is likely to have a detrimental effect on mechanical properties of concrete. Especially for bridge decks and airport pavement with high requirements for impact resistance, toughness, and crack resistance, the use of expansion agents alone cannot meet the performance requirements. In this study, the mechanical properties and autogenous shrinkage of concrete were studied when MgO expansion agent (MEA) and steel fiber were used simultaneously. The results showed that the expansion produced by MEA increased the porosity while compensating for the shrinkage of concrete. Compared with plain concrete, the porosity increased by 4.4% when MEA was incorporated alone. After MEA and steel fiber were used simultaneously, the steel fiber constrained the expansion of MEA through the adhesive friction between fiber and matrix, which made the interface transition zone (ITZ) between cement paste and fiber densified. In this way, the shrinkage of concrete was avoided without reducing the mechanical properties. Especially when 8% MEA and 1% steel fiber were used simultaneously, the compressive strength and splitting tensile strength of concrete were increased by 20.6% and 65.0% respectively, and the porosity was decreased by 20.9%. The expansion of concrete at 410d when used simultaneously was 371 × 10−6, which was 20.7% lower than that of MEA alone, avoiding the possible adverse effects of excessive expansion of MEA. The research results have guiding significance for improving the crack resistance and impact resistance of concrete.

Mathematical Modeling for Evaluating the Mechanical Properties of High Strength Concrete with Natural Zeolite and Additives

Mathematical Modeling for Evaluating the Mechanical Properties of High Strength Concrete with Natural Zeolite and Additives

Influence of Natural Fiber Derived from Agricultural Waste on Durability and Micro-Morphological Analysis of High-Strength Concrete

This research focuses on the investigation of durability behavior and microstructural analysis for M70 grade of high-strength concrete (HSC) with the influence of alccofine, banana fiber (BF), and coir fiber (CF). In this investigation, cement was partly supplanted by 15% of alccofine content in weight. Two types of natural fibers, banana and coir fibers, were selected and added in concrete at 0.5%, 1%, 1.5%, and 2% by volume. Durability characteristics, such as long-term compressive performance, rapid chloride penetration, sorptivity, water absorption, volume of permeable voids, and acid attack resistance are investigated elaborately and correlate with conventional HSC. Results showed that the incorporation of banana and coir fibers with alccofine in HSC exhibited good durability performance as correlated with conventional HSC. At 180 days of curing, incorporating 1% of banana fiber increased the durability performance compared to reference HSC. Nonetheless, the high-fiber percentage of HSC has a slight reduction in durability characteristics. Among the two types of fibers, the banana fiber showed the most significant improvement in the durability properties of HSC. The influence of natural fiber on the microstructural characteristics of HSC was evaluated using scanning electron microscope (SEM), X-ray diffraction (XRD), and Fourier transform infrared (FTIR) to substantiate the experimental findings. In contrast, using additional supplementary cementitious materials (SCMs) in HSC fabrication significantly reduces cement usage and carbon emissions.

Experimental investigation on workability and mechanical properties of carbon fiber reinforced high-strength concrete (HSC) containing waste bakelite aggregate (WBA)

High-strength concrete (HSC) is a type of concrete that is, due to its improved mechanical and durability properties, most often used in the construction of high-demand structures such as bridges, structural elements in aggressive environments, skyscrapers, and large-span constructions. In order to obtain high-strength concrete, a larger amount of cement is required, which can lead to questionable ecological acceptability of this material. To reduce the ecological footprint of this material, supplementary cementitious materials such as silica fume or metakaolin are often used. By reducing the porosity and increasing the density of the concrete mixture, fine particles of supplementary cementitious materials have a positive effect on the mechanical and durability properties of high-strength concrete. Along with cement and supplementary cementitious materials, another important component of high-strength concrete is aggregate, which is in most cases a fine aggregate. In this research, the natural fine aggregate was partially replaced with bakelite plastic waste, and the influence of this replacement on the fresh and hardened properties of high-strength concrete was presented. Seven mixtures were designed, a reference mixture and six other mixtures in which supplementary cementitious materials, waste bakelite aggregate, and carbon fibers were combined to produce environmentally friendly high-strength concrete. 5 % of the cement mass was replaced with silica fume or metakaolin, 10 % volume of natural fine aggregate was replaced with waste bakelite aggregate (WBA) and carbon fibers were added in the amount of 0.5 % of the cement mass. In a fresh state, the workability of HSC is determined by using a flow table. To determine the influence of waste bakelite aggregate on mechanical properties, flexural and compressive strength tests were carried out on 7- and 28-day-old samples. The test results indicate that the combined effect of waste bakelite aggregate, supplementary cementitious materials, and carbon fibers can be a promising solution not only to improve high-strength concrete mechanical properties but to potentially save millions of tons of natural fine aggregate and preserve natural resources and the environment.

Estimation of physical and mechanical properties of high-strength concrete with polypropylene fibers in high-temperature condition

High-strength concretes (HSC) have been widely applied in civil construction. However, this material does not perform well in fire situations due to spalling, a phenomenon that can be significantly mitigated by adding synthetic fibers to HSC cementitious matrix. Estimating HSC physical and mechanical properties for different compositions and temperatures can therefore be useful, as the structure may be pre-designed without requiring prior material characterization in a fire situation. With this perspective, this paper aimed to propose regression models to estimate eight properties of High-Strength Concrete with Polypropylene Fibers (HSC-PPF), namely compressive strength, tensile strength, static modulus of elasticity, dynamic modulus of elasticity, ultrasonic pulse velocity, electrical resistivity, water absorption, and weight loss, at high temperatures (up to 800 °C). For this, it was evaluated the effective correlation between mechanical responses and independent variables, such as temperature, water absorption, and dynamic modulus, and the accuracy of regression models was assessed. The results obtained indicated that, among the models proposed, the two multiple regressions were better than the simple one for estimating HSC-PPF properties since they presented high adjustments (R2) and low mean absolute percentage (MAPE), and coefficient of variation (CV) errors. This methodology can be used in a wide variety of fiber-reinforced HSCs.

A Systematic Review of Properties of High-Strength Concrete using Rice Husk ash as a Replacement

The investigation aims to analyse potential methods of augmenting high-strength concrete's (HSC) quality by incorporating Rice Husk Ash (RHA). Residue from incinerated rice husks, commonly known as RHA, has been applied to concrete to enhance material durability and strength since ancient times. Research conducted on high-strength concrete (HSC) sought to investigate how RHA affects its endurance and fortitude. The study featured a composition range from 0.3% - 1.2% RHA content density in HSC blends. It was discovered that adding RHA improved both compressive force resistance and splitting tensile control potency within these mixtures by an average increase of 6.2%, whereas abounding with up to or exceeding 14.7%. Furthermore, water permeation capabilities were bolstered alongside chloride infiltration defence attributes among this kindred variation; suggesting it could function reliably as an admixture suitable for improving structural robustness when added at significant ratios into High-Strength Concrete compositions- thereby proving itself effective overall towards achieving optimal enhancements across multiple facets affecting longevity & sturdiness alike over time through rigorous testing protocols established during our analysis period.

Effect of basalt minibars on the shear strength of BFRP-reinforced high-strength concrete beams

This research examined the effect of a novel type of stiff nonmetallic macro fibers, basalt macro fibers (BMF), on the shear strength and behavior of high-strength concrete (HSC) beams longitudinally reinforced with basalt fiber-reinforced polymer (BFRP) bars. Nine BFRP reinforced concrete beams (BFRP-RC) were cast and tested under two-point loads without BFRP stirrups. The volume fraction of BMF (Vf) and the BFRP longitudinal reinforcement ratio (ρf) were all evaluated; three volume fractions of BMF were used (0%; 0.75%; 1.5%), with three longitudinal reinforcement ratios (0.71%, 1.71%, and 2.54%). The results indicated that adding BMF to HSC-BFRP-RC beams enhanced the shear resistance. For concrete compressive strength of 90 MPa, the results show that adding BMF enhanced the shear resistance for all flexural reinforcement ratios; however, it is more effective in beams reinforced with a higher flexural reinforcement ratio. For beams reinforced with flexural reinforcement ratios of 0.71% and 2.54%, the shear resistance increased by 95% and 98%, respectively, due to adding 0.75% BMF, compared to 136% and 210% when 1.5% of BMF were added. And the post-cracking stiffness of all beams remarkably increased due to BMF addition. Furthermore, the effect of BMF on the mechanical properties of HSC was investigated. Finally, ACI 318–19, ACI 440.1R-15, and ACI 544.4R-18 were evaluated to predict the ultimate shear strength of HSC-BFRP-RC beams reinforced with BMF. The experimental results correspond well with ACI 544.4R-18 predictions of the shear strength of fiber-reinforced concrete (FRC) beams without shear reinforcement.

Influence of Salinity of Mixing Water Towards Physical and Mechanical Properties of High Strength Concrete

Influence of Salinity of Mixing Water Towards Physical and Mechanical Properties of High Strength Concrete

Impact strength and mechanical properties of high strength concrete containing PET waste fiber

This study presents results of tests done on workability, mechanical properties, first cracking impact and ultimate load impact of high strength concrete (HSC) contained polyethylene terephthalate (PET) waste fiber. Different PET fibers with regard the length (10 mm, 20 and 40 mm) were added to concrete by 0.50, 0.75, 1.00, 1.25 and 1.50% (by volume). Density, ultrasonic pulse velocity, compressive strength, splitting tensile strength, flexural strength, first crack impact (N1) and ultimate load impact (N2) tests were conducted on sixteen HSC mixes. Results showed a slight change in ultrasonic pulse velocity, while addition of PET fiber with 10 mm, 20 mm and 40 mm length reduced compressive strength by a maximum value of 15.74, 14.37 and 10.28% respectively compared to control concrete. Regardless to the fiber length and fraction volume, fiber content improves splitting tensile and flexural strengths by a maximum of 63.3% and 24.7% respectively. Striking results were recorded against impact strength property, in which improvement in N1 recorded up to 300% and N2 up to 833% depending on fiber length and fraction volume. It is concluded that PET waste fiber can improve important properties of HSC and it is recommended to be added to concrete by up to 1.5% by volume. Regression analysis was made to develop equations for calculating N1 and N2, and these properties were found to depend essentially on compressive strength of plain concrete and PET fiber parameters.

Cracking failure behavior of high strength concrete containing nano-CaCO3 at early age

Nano-calcium carbonate (CaCO3) has been added to high strength concrete (HSC) to reduce cement usage, control greenhouse gas emissions, increase durability, and control excessive shrinkage of HSC. Many investigations on the mechanical properties and shrinkage of HSC containing nano-CaCO3 have conducted. However, the early-age cracking failure behavior of that considering temperature, shrinkage, restrained stress, and tensile creep simultaneously was rarely investigated. Temperature stress test machine, which could measure these factors simultaneously, was used to investigate the influence of nano-CaCO3 contents (0%, 1%, 2%, and 3% by weight of cement powder) on the early-age cracking failure behavior of HSC in the present investigation. Mechanical properties of HSC containing nano-CaCO3 were tested. The addition of nano-CaCO3 to HSC improved the mechanical properties, and reduced the tensile creep as well as autogenous shrinkage of that at early age. A simplified stress-strain failure criterion was proposed.

Investigating The Mechanical Behavior of High-Strength Concrete Reinforced with Hooked Steel Fibers

The engineering properties of high-strength concrete are significantly different from those of ordinary concrete, and as a result, this concrete has become popular in a variety of applications, including the construction industry, particularly for tall buildings, bridges with long spans, and precast members. Reinforcing high-strength concrete using fibers is a common method for increasing ductility without losing strength. In this study, steel fibers were employed to replace 1, 1.5, 2, and 2.5 percent of the total volume of concrete, and a total of 5 mixed designs were conceived and constructed. The findings showed that the addition of steel fibers up to 2% by volume boosted the compressive strength and decreased at 2.5% by volume. The incorporation of steel fibers has diminished the mixes' durability.