Self-compacting High Performance Research Articles

Empirical Modeling of High-Performance Self-Compacting Concrete with Induction-Furnace Slag

Abstract This study led to the creation of empirical models of the properties of high-performance self-compacting concrete (HPSCC) with inductionfurnace slag (IFS) added as an extra cementitious ingredient. The ingredients were Portland cement, IFS ranging from 0 to 50% by cement weight, granite, river sand, water, and superplasticizer. Using a slump flow test, the filling-ability property of the newly produced HPSCC was investigated. Similarly, a compressive strength test was used to determine the hardened HPSCC's compressive strength. Using already established scientific ideas, the empirical model of the filling-ability characteristic of the fresh HPSCC was generated, on the basis of the slump flow and the volume of the paste of the fresh concrete. Likewise, the empirical model of the compressive strength of the hardened HPSCC was generated, based on the combination of the parameters of the strength developed over time, with the strength developed, due to the addition of the IFS. Based on these, the empirical model of the fillingability property of the fresh HPSCC was ρ r s f 2 = 0.002 ( 1 - V P ) - 11.34 {{{\rho _r}} \over {{s_f}^2}} = 0.002{\left( {1 - {V_P}} \right)^{ - 11.34}} , while that of the compressive strength of the hardened HPSCC was f c ( t ) = t 4.52 + 0.78 t ( − 0.0109 ( P i f s ) 2 + 0.2632 P i f s + 52.446 ) {f_c}\left( t \right) = {t \over {4.52 + 0.78t}}\left( { - 0.0109{{\left( {{P_{ifs}}} \right)}^2} + 0.2632{P_{ifs}} + 52.446} \right) . The empirical models were then validated using test data from this work. Strong links between the measured and the predicted values were identified by the empirical correlations, where the coefficient of determination (R2) value for the filling ability property, gave above 94% and the R2 value for the compressive strength, gave above 86%. The estimated slump flow and the compressive strength were approximately equal to the experimental values. The outcomes demonstrated that IFS may be utilized to produce an eco-friendly and environmentally sustainable HPSCC. The models can be adopted in designing HPSCC containing IFS as a supplementary cementitious material (SCM) and in predicting its filling-ability and compressive strength, which will benefit the construction industry.

High-performance self-compacting concrete with recycled coarse aggregate: comprehensive systematic review on mix design parameters

ABSTRACT The technological advancements and environmental concerns enlighten the importance of incorporating more high-performance engineered materials in the construction sector. The partial replacement of natural coarse aggregates (NCA) with recycled coarse aggregates (RCA) in concrete has recently been a primary focus of worldwide researchers for sustainability in environmental aspects. The primary purpose of this review is to comprehend the effect of design parameters in determining the mechanical characteristics of high-performance self-compacting (HP-SCC) that include recycled coarse aggregates (RCA). Seven design parameters were extracted and considered in this review. It has been revealed that the design parameters of HP-SCC with RCA have a different effect on the mechanical characteristics of HP-SCC with various grades. In addition, the current research aims to promote environmental-friendly development and produce sustainable materials to improve mechanical-related characteristics in concrete in the absence of a precise evaluation technique. Artificial neural network (ANN) models have been implemented using the design parameters for predicting concrete mechanical properties based on three statistical indicators. The ANN-based model was attributed using these seven inputs of the literature with the help of sensitivity analysis for indicating the most critical design parameter HP-SCC.

Fresh and Mechanical Properties of High-Performance Self-Compacting Concrete Containing Ground Granulated Blast Furnace Slag and Polypropylene Fibres

The purpose of this study was to evaluate the appropriateness of polypropylene fibres (PP) to decrease the brittleness of high-performance self-compacting concrete (HPSCC). The influence of PP fibre content on the fresh and mechanical assets of PP-fibre-reinforced HPSCC was investigated. PP fibres were applied with 0, 0.025, 0.05, 0.075, 0.125, 0.25% contents to the HPC blends with high cement replacement by ground granulated blast furnace slag (GGBS). The impact of PP fibre fraction on fresh properties of HPSCC, counting passing capability as well as filling parameters is discussed. In addition, the mechanical properties, i.e., compressive, splitting tensile, and flexural strengths, were evaluated after 7 and 28 days of specimens’ maturation in water. The higher content of PP fibres gradually reduced the HPSCC workability and improved the mechanical properties. The high performance of fresh and hardened ecological HPSCCs containing 46% GGBS instead of cement with 0.025–0.25% PP fibre content proves the great potential of using these composites in various applications in the construction industry. The advantages of the potential recycling of GGBS include, among others, the reduced use of cement in a durable material, reduced amount of waste in landfill and lower emission levels of greenhouse gases.

Performance evaluation of high-performance self-compacting concrete with waste glass aggregate and metakaolin

High-Performance Self-Compacting Concrete (HPSCC) has attracted much attention in recent decades due to its remarkable ability to fill formworks with densely packed reinforcing bars while requiring minimal or no external compaction. Because of the negative environmental impacts of cement and natural aggregates in concrete production, a much more sustainable alternative to manufacturing HPSCC is required. Recycled glass waste is one of the most attractive waste materials that can be used to create sustainable concrete compounds, which is currently a major area of study among researchers. This study aims to develop information not only about the fresh, mechanical, and durability characteristics of HPSCC, evaluate the environmental impact and correlate the crushing strength using a non-destructive approach by utilizing waste glass aggregates at replacement percentages of 0%, 10%, 20%, 30%, and 40%. To improve the performance of the produced HPSCC, Metakaolin was also added. The results of the fresh concrete tests revealed that the substitution of an optimal level of waste glass with Metakaolin provides adequate implementation in flowability, passing ability, and viscosity behaviors. Even though there is a reduction in the mechanical performance with glass aggregates, Metakaolin significantly improved strength and ductility by up to 16.12% and 15.91%, respectively. Furthermore, in most cases, the use of glass aggregates with Metakaolin significantly alters the durability properties of concrete while minimizing the environmental impact as well as the overall project cost. Finally, the NDT assessment demonstrates that the analytical equation can efficiently predict the compressive strength and promising to use for field application.

Statistical Models Supporting the High-Performance Self-Compacting Concrete (HPSCC) Design Process for High Strength.

The type of test ingredients used for obtaining self-compacting high-performance concrete (HPSCC) has been carefully selected to be universal. For this purpose, an extensive statistical analysis of the obtained results of the literature research was carried out. Then, universal and adapted to the typical range, highly fit statistical models are presented that can support the HPSCC design process for achieving high strength. For this purpose, a broad plan of statistical research was used, namely multivariate selection of sidereal points, which allowed the use of as many as five variable factors at three levels of variability. The sidereal points were equal to the respective minimum and maximum input values. Additionally, based on the analysis of variance (ANOVA) for factorial systems with the interaction of the obtained test results, the significance of the impact of the tested material factors on the compressive strength of the HPSCC tested was determined.

Development of Variants of High-Performance Self-Compacting Concrete with Improved Resistance to the Attack of Sulfates

This paper presents experimental and analytical work of which the main objective was to support the introduction of a new technology for the production of sewer pipes. In this technology, the pipes produced consist of two differently produced parts. The direct part uses conventional vibro press compacted concrete. In the curved part, on the other hand, self-compacting concrete technology is used. The cooperating company, Prefa Brno a.s., defined possible negative effects on concrete of sewer pipes. The task of the research team and now the author’s team was to propose a procedure for the development of suitable self-compacting concrete variants and subsequently the design of a methodology to verify their durability in aqueous environments containing sulfates. To increase the efficiency of the development, the model mortar method was used in the experimental work. That is, instead of the original concrete, a model mortar derived from it was tested. The principle and procedure of derivation of model mortars are described in the paper. In total, eight variants of model mortars were tested, and at least three of them fulfilled the requirements. An optional but beneficial part of the carried out work was the derivation and practical application of the time-anchored-triangles-of-cracking graphical method developed during the research. This method is used to quickly compare the degree of attack of different silicate composites tested in a common bath inducing type III corrosion.

Fresh Characteristics of High-Performance Self-Compacting Concrete using Induction Furnace Slag as Supplementary Cementitious Material

Using wastes products in concrete contributes towards sustainability in civil engineering construction. Producing high-performance-self-compacting concrete (HPSCC), using induction furnace slag (IFS) contributes positively to the sustainability of concrete technology. Many researchers have developed self-compacting concrete (SCC), but there are minimal investigations reported considering the high-performance in the development of SCC. The aim of this paper is to determine the fresh characteristics of HPSCC, using IFS as a supplementary cementitious material. Tests were conducted on filling ability, passing ability, as well as resistance to segregation of the fresh HPSCCs, containing IFS at percentage replacement of 0%, 10%, 20%, 30%, 40% and 50%. Slump flow and T50cm slump flow tests were conducted to determine the filling ability. L-Box test was used to determine the passing ability. V-funnel at T5minutes test was conducted to determine the resistance to segregation. The results showed that the slump flow ranged between 652 and 687 mm, the T50cm slump flow ranged between 2.59 and 3.97 seconds, the L-box value ranged between 0.81 and 0.95, while V-funnel at T5minutes ranged between 1.88 and 3.11. The fresh properties criteria, according to EFNARC were fulfilled, except for few concretes with IFS content greater than 20%. It is therefore recommended that induction furnace slag be incorporated as a supplementary cementitious material (SCM) when producing HPSCC.

Fresh and hardened properties of self-compacting high performance concrete containing nano-metakaolin as a partial replacement

In this study, the effect of partial substitution of cement material with nano-materials represented by nano-metakaolin(NMK) has been studied on the fresh and hardening properties of High-Performance Self-Compacting concrete (SCHPC), where the substitution was made in different proportions, namely (1.25, 2.5 and 3.75). Four mixtures were made, the first reference and the remaining three mixtures in which the cement was partially replaced by the above mentioned proportions. Fresh characteristics represented by the Slump flow, T5 0 c m, the L- box and the V- funnel were studied. As for the hardening properties, the compression and tensile strengths were examined. We observed through practical results that the Slump flow and L- box values decrease as the percentage of partial substitution of cement to nano-metakaolin increases. Whereas, T5 0 cm and T v It increases with the increase in the partial substitution rate for cement with nanometakaolin. As for compressive strength and tensile strength, it increases with the increase in the percentage of partial replacement of cement with nano-metakaolin.

Experimental Investigation of Self-compacting High Performance Concrete Containing Calcined Kaolin Clay and Nano Lime

The aim of this research is to investigate the effect of pozzolanic materials and nano particles on improve the strength characteristic by the properties of a self-compacting high-performance concrete that includes calcined clay with nano lime. In this study, two blends systems are worked on, they are the binary and the ternary systems. For binary mixtures, test samples were prepared from 5% CC, 10% CC, 15% CC and 3% NL by partial replacement of the cement weight. While ternary mixtures, samples were prepared from 5% CC 3% NL, 10% CC 3% NL and 15% CC 3% NL by partial substitution of cement weight. The tests conducted on mixes are fresh tests like slump flow diameter, V-funnel, L-box, and segregation resistance. The compressive strength test was determined at 7, 28 and 56 days. While splitting tensile strength tests at 7 and 28 days from the SCHPC produced in the study. It was concluded that the replacement of CC and NL in SCHPC binary mixes reduced the fresh results enough for SCHPC production and gave a general improvement in the compressive strength and splitting tensile strength properties of the SCHPC mixture. SCHPC with 10% CC partial replacement of cement showed higher values of compressive and splitting tensile strength, compared to the reference mixture of SCHPC for all days, thus it was considered the best. Whereas, the strength of the concrete mixtures in the ternary cement mixtures was better than the strength of the mixing and control mortar systems for the same replacement levels in 7 , 28 and 56 days.

High-Performance Self-Compacting Concrete with Recycled Aggregates from the Precast Industry: Durability Assessment

The main objective of this paper is to provide the industry with a simple and practical way of disposing and recovering recycled waste from precast reinforced concrete elements rejected during the quality control process, while minimizing the consumption of natural resources in the production of concrete and, consequently, significantly reducing the environmental impact of both (construction and demolition waste and extracting natural aggregates). In other words, with this work, the intention is to evaluate the feasibility of producing high-performance self-compacting concrete with a less environmental impact, by replacing natural aggregates (NA) with fine and coarse recycled aggregates resulting from the precast industry, which allows the future use of this type of aggregates in the industrial process without reservations concerning the expected durability performance. To achieve these objectives, six types of self-compacting concrete (SCC) were produced incorporating different amounts of recycled aggregates. Six replacement ratios for fine recycled aggregates (FRA) and coarse recycled aggregates (CRA) were considered: (FRA/CRA) 0/0; 25/25; 50/50; 100/100; 0/100 and 100/0%. Six different tests were carried out to characterize both the main concrete transport mechanisms and the main concrete degradation mechanisms, namely: the immersion water absorption test, capillary water absorption test, oxygen permeability test, chloride migration test, electrical resistivity test and carbonation test. The obtained results clearly demonstrate that, despite the negative influence of the inclusion of recycled aggregates, it is still possible to produce high-performance self-compacting concrete with perfectly acceptable durability properties.

UTILIZATION OF ADMIXTURES IN SELF-COMPACTING HIGH PERFORMANCE CONCRETE

Flow-able concrete or self-consolidating or self-compacting concrete (SCC) is a particularly flow-able, non-segregating concrete which flows, plugs form-work, and captures the utmost congested rebars with none use of mechanical vibration. When used with admixtures to enhance the performance of concrete, it is called as self-compacting high performance concrete. An extant literature survey was taken up to understand the utilization of waste polyethene, fly ash and micro-silica in SCC to make it a SCHPC. It has been seen that very less amount of research work is available on use of waste polythene in conventional concrete as well as SCC. A few studies have reported positive results towards the mechanical properties i.e. compressive strength and flexural strength of concrete while no literature is available taking into account its initial cost and the durability aspects of such concrete.

Does the Carbon Fibre Coating Reinforcement Have an Influence on the Bearing Capacity of High-Performance Self-Compacting Fibre-Reinforced Concrete?

This study investigated the impact of the location of a carbon fibre coated reinforcement ring (CFCRr) inside the structure of high-performance self-compacting fibre-reinforced concrete (HPSCFRC). Nowadays, cement matrix is considered as an alternative binder when reinforcing concrete structures with composite materials. Due to the plastic behavior of composite structures at relatively low temperatures when carbon fibres are reinforced with epoxy resin, the author attempted to locate carbon fibres inside a concrete structure. Thanks to this, the reinforcement will be less vulnerable to high temperatures (during a fire) and more compatible with concrete. The fibres act as a perimeter reinforcement that is compatible with the concrete mixture. The position of the CFCRr in the structure of concrete has an influence on the load capacity, stiffness and stress-strain behavior of concrete elements. The research was conducted on circular shape short concrete columns and tested under axial compression. The results demonstrated that by including CFCRr inside a concrete specimen, the maximum compressive strength decreases with an increase in the number of composite rings and a greater distance from the vertical axis of symmetry to the edge of the element. It has been proven in these studies that carbon fibres do not have good adhesive properties between CFCRr and a concrete mixture. As a result of this phenomenon, a shear surface is created, which leads to crack propagation along the CFCRr. Therefore, the presented idea of an internal CFCRr should not be used when designing new concrete structures.

Fresh-State and Mechanical Properties of High-Performance Self-Compacting Concrete with Recycled Aggregates from the Precast Industry.

The urgent need to change the less positive impacts of the construction industry on the environment, and more specifically the production and use of concrete, is the main motivation for the research for more efficient and environmentally sustainable solutions. This paper presented the results of an experimental campaign whose ultimate goal was to produce high-performance self-compacting concrete (SCC) using recycled aggregates (RA) from the precast industry. The results of the fresh-state and mechanical properties tests performed on six concrete mixes (using RA from the precast industry) were presented. The first concrete mix is a reference mix using natural aggregates only (100% NA), and the remaining five mixes had various contents of fine (FRA) and coarse (CRA) recycled aggregates in concrete’s composition: (2) 25/25% (25% RA); (3) 50/50% (50% RA); (4) 100/100% (100% RA); (5) 0/100% (100% CRA); (6) 100/0% (100% FRA). The results showed that the high-performance concrete mixes with RA from the precast industry performed worse than the reference mix. However, taking into account all the mechanical properties studied, it can be concluded that RA from precast concrete elements are of very good quality and can be incorporated in the production of high-performance SCC. The potential demonstrated by the combined use of fine and coarse recycled aggregates was also emphasized. This type of work is expected to effectively contribute to raise awareness among the various players in the construction industry, particularly in the precast concrete industry, to the feasibility of using RA in significant quantities (notably coarse aggregates) and to the safety needed to assume structural functions, even for applications where high performance is required.

Studies on high performance alkali activated slag concrete mixes subjected to aggressive environments and sustained elevated temperatures

In contemporary constructions, there is a continuous drive for enhancing the performances of concrete mixes, both green and as well as on hardened state. Again there are simultaneous efforts to take full advantage of all the various fast-track, state-of-art construction technologies, leading to early completion of efficient, economical and eco-friendly infrastructure projects. The present authors have developed a new class of high performance self-compacting, alkali activated slag concrete mixes (HPAASC) using three industrial by-products, all obtained from iron and steel industry and have evaluated them for their strength properties. While these HPAASC mixes have higher compressive strengths (about 70–90 MPa) and reasonable split-tensile and flexural strengths, they are also self-compacting in nature. In the present paper, the durability performance of this class of mixes on long-term exposure to aggressive environments like acids, sulphates and chlorides is discussed. Strength deteriorations of the standard test specimens subjected to 5% concentrated sulphuric acid solution and so also in 10% magnesium sulphate solution were monitored for a period of one year. The impermeability of the mixes against chloride-ions was evaluated using both Bulk diffusion test (BDT) and the Rapid chloride penetration test (RCPT). Further these mixes were also evaluated for their performance on exposure to sustained elevated temperatures in the range of 200–800 °C. All the specimens were further analysed for their microstructural studies. Results in the present study indicate that, all the HPAASC mixes exhibit better resistances to aggressive environments and sustained elevated temperatures as compared to the OPC-based reference concrete mix.

Numerical Modeling of the Casting Process and Impact Loading of a Steel-Fiber-Reinforced High-Performance Self-Compacting Concrete

With the rapid development of high-performance self-compacting fiber-reinforced concrete materials, advanced numerical modeling tools have become necessary to design optimum materials and structures. A simulation framework that includes numerical modeling of the flow of a high-performance self-compacting fiber-reinforced concrete mortar during the casting process, calculation of local fiber orientation based on the deformation gradient in the mortar, and impact modeling taking into account the local fiber orientation is proposed. A new method to calculate the probability of fiber orientation distribution by particle tracking and approximation of particle motion using the deformation gradient is proposed. A discrete lattice modeling technique, with a nonlinear strain-rate- and local-fiber-orientation-dependent constitutive law for a numerical impact modeling is proposed. Single- and three-point concrete casting techniques are numerically simulated, and results are compared with experimental measurements, showing a good agreement. The numerical models revealed that fiber orientation and the impact resistance of beams strongly depended on the casting technology of the self-compacting concrete. The numerical model proposed can be used to design efficient concrete casting technologies ensuring the necessary fiber orientation in load-bearing structures..

Properties of High-Performance Self-Compacting Rubberized Concrete Exposed to High Temperatures

AbstractSelf-compacting concrete (SCC) is a unique type of concrete material where vibration or compaction is avoided by including super plasticizer in the fresh mixture to achieve homogenous compa...

Development of Bond Strength of Reinforcement Steel in New Generation Concretes

The paper presents an experimental investigation of the steel-to-concrete bond using a pull-out test. Namely, the development of bond strength of reinforcement steel in new generation concretes was investigated. In the tests high-performance self-compacting (HPSCC) and vibrationally consolidated concretes (HPC), with the same water-to-binder ratio and made of components with the same properties, were used. For comparison purposes, the normal concrete was also used. For each concrete used in the experiment, a compressive strength development test was performed. To assess the development of bond strength in the tests, cubic specimens with the dimensions 160x160x160 mm were used. In each test element, ribbed reinforcing bar with a diameter of 16 mm was embedded in. Two variants of orientation of reinforcing bars with respect to the direction of concreting were considered - perpendicular and parallel. Test results showed that the development of bond strength between steel rebars and concrete increases with the increasing age. Additionally, the bond strength between steel rebars and concrete escalated with the increasing concrete strength. However, the development of bond stress with age was faster than the development of compressive strength, especially at early test ages. No significant difference was noticed between HPC and HPSCC mixes in terms of bond or compressive strength development with age. The conducted studies showed that in new generation concretes as well as in normal concretes the rebars placed parallel to the direction of concreting obtained higher values of the bond strength in comparison to rebars placed perpendicularly. This behaviour was observed in all stages of bond development.

An experimental investigation on the shear and flexural behavior of steel reinforced HPSCC beams

High-Performance Self-Compacting Concrete (HPSCC) has experienced increasing demand over the past few years due to its enhanced mechanical properties and high bonding strength. These attributes make it preferable for use in structures, such as tall multi-story buildings, where high workability, strength and bending capacity are required. The objective of the present study is to investigate the shear and flexural behavior of HPSCC beams with no coarse aggregate and compressive strength of above 100 MPa. The influence of different types of steel fibre on the mechanical properties and failure modes of reinforced HPSCC beams were studied. In addition, the influence of the beam's span to effective depth ratio (a/d), longitudinal and transverse reinforcement ratios on the behavior of the HPSCC beams was studied. The results showed that the influence of the type of steel fibre is more significant than the influence of longitudinal reinforcement ratio. Moreover, the ultimate load and deformation capacity of HPSCC beams increased considerably for the beam specimens with steel fibre. However, it was shown that the non-fibre beams with d/4 shear link spacing had a higher ductility compared to the counterpart steel fibre beams with d/2 shear link spacing and with the same amount of longitudinal reinforcement ratio.

The Top-Bar Effect in Specimens with a Single Casting Point at One Edge in High-Performance Self-Compacting Concrete

The Top-Bar Effect in Specimens with a Single Casting Point at One Edge in High-Performance Self-Compacting Concrete

The impact of coarse aggregate shape on the behavior of self-compacting high-performance concrete

Self-Compacting High Performance Concrete (SCHPC) presents a crucial step in the development of concrete technology. The most important features of self-consolidating concrete are flowability, segregation resistance and passing ability. Generally, the rheological properties are modified by effective superplasticisers and water to binder ratio. The aim of this study is to focus on the important aspect of the impact of shape of the coarse aggregate on fresh concrete mixture properties, strength and deformability of SCHPC. Coarse aggregate is a significant proportion of the concrete volume and therefore has a meaningful influence on its quality. By appropriate selection of the shape of the grain aggregate, it is possible to affect the rheological parameters of concrete. The results presented in this study indicated that the shape of the grains of coarse aggregate has an impact on the strength and stiffness of SCHPC. Moreover, the occurrence of irregular grains of coarse aggregate causes lower slump flow and higher plastic viscosity in comparison to concrete mixtures with regular grains only. The research presented in this article is part of the author's wider research devoted to this issue.