Properties Of Self-compacting Concrete Research Articles

Effect of combination between hybrid fibers and rubber aggregate on rheological and mechanical properties of self-compacting concrete

Rubber aggregate recycled from waste tires are added to self-compacting concrete to improve some of its properties, such as durability, toughness, and concrete resistance to impact and vibrations. In this study, modified hybrid rubberized self-compacting concrete (SCC) was produced by utilization of recycled tire rubber aggregate, plastic waste (PET), and steel fibers. Rubber was used as a partial substitute for sand, with only 10%, while the fibers were utilized in two different proportions of 0.25% and 0.35% (volume). Several tests were achieved to evaluate the rheological properties of the modified hybrid fiber rubberized SCC such as slump flow, T500, V-funnel, L-box, and segregation resistance. In addition, the hardened properties such as density, compressive, tensile strengths, and modulus of elasticity were evaluated. Microstructural evaluation of rubberized mixes was conducted. The results showed that the addition of rubber aggregate at 10% content reduces the rheological properties of SCC. The T500 mm was influenced significantly up to 15% increase. Moreover, compressive strength decreased by about 14% at same amount of rubber aggregate, while the addition of hybrid fibers improves the mechanical properties despite the negative effect on the rheological properties of rubberized SCC. The tensile strengths increased significantly by the inclusion of 0.35% hybrid fibers. The positive action of the two types of fibers led to this increase. The combination of rubber aggregate and the hybrid fibers in SCC could affect its mechanical properties positively by balancing the weakness in strength due to the lack in of bonding between rubber aggregate and cement paste and to avoid the severe deterioration in tensile strength, improve the ductility, and enhance the energy absorption capacity, especially for members subjected to earthquake effects.

The effect of using treated domestic wastewater with different pHs on workability, mechanical, and durability properties of self-compacting concrete.

In the present work, we used treated domestic wastewater with different pHs in self-compacting concrete (SCC) to find the effect of treated wastewater with different pHs on the workability, mechanical, and durability properties of SCC. Eight different SCC mixtures were designed, including two control samples using tap water with a water-to-cement ratio (W/C) of 0.5 with 400 kg/m3 of cement and W/C of 0.36 with 440 kg/m3 of cement. Six SCC samples with the same characteristics as control samples except using treated domestic treated wastewater with different pHs. The results indicate that the workability of the SCC sample using the treated domestic wastewater in acidic pH was higher than the alkalinity state. Using treated domestic wastewater instead of tap water in SCC samples decreased compressive, flexural strength, and fracture toughness by less than 10%. Also, carbonation, 30-min water adsorption, and capillary water adsorption of SCC samples increased when treated domestic wastewater was used. The compressive strength of SCC samples made with treated domestic wastewater in an acidic state is less than about 5% in an alkaline state. The energy dispersive spectroscopy and the scanning electron microscope images confirmed that using treated wastewater instead of tap water, in SCC samples, reduced compressive strength because the Ca/Si ratio increased when treated domestic wastewater was used. The SCC samples with treated domestic wastewater in the alkaline state have a lower Ca/Si ratio. The higher compressive strength belongs to concrete samples that used treated domestic wastewater in an alkaline environment with a lower Ca/Si ratio.

An investigation of the effect of high temperature on the strength compression and ultrasonic pulse velocity of self-compacting concrete

One of the most significant mechanisms of deterioration in self-compacting concrete (SCC) structures over the course of their service life is exposure to elevated temperatures. For this reason, the effects of elevated temperatures on the residual mechanical properties of SCC made of various cementitious additions (silica fume (SF), limestone filler (LF), and crushed dune sand (SD)) was investigated via partially substituting amount of Portland cement in the SCC. The SCC was formed and heated with the coupling procedure of heating-cooling at ambient temperatures ranging from 20, 150, 400, 600, and 800 °C. The compressive strength (CS) and ultrasonic pulse velocity (UPV) were measured after cooling at room temperature of 20 °C. The findings show that CS and UPV exhibit intriguing outcomes for all self-compacting concretes. Otherwise, the UPV decreases with temperature in the range of 250 and 800 °C. In addition, at 600 °C, SCC-SF and SCC-SD have the highest residual compressive strengths, 31.20 and 23.80 MPa, respectively.

An Experimental Study on Strength and Durability of Concrete by Partial Replacement of Coarse Aggregate with Steel Waste and Fine Aggregate with Copper Waste

Global warming and environmental destruction have become the major issue in recent years. Emission of greenhouse gases from industries has impact on climate change. Preventing the depletion of natural resources and enhancing the usage of waste materials has become a challenge to the scientist and engineers. A number of studies have been conducted concerning the protection of natural resources, prevention of environmental pollution and contribution to the economy by using this waste material. The major byproducts of industry are slag. To solve the problem in effective manner slag is use in concrete by replacing natural coarse aggregate. In this study, the replacement was done with coarse aggregate by steel waste and copper for a M20 grade of concrete is used for a water cement ratio of 0.40.Tests on compressive strength at 7 days and14 days are conducted on specimens. The optimum strength is obtained on 30% replacement of coarse aggregate and fine aggregate by steel waste and copper waste. All mechanical properties were enhanced with the use of copper slag. Copper slag improved the resistance against chloride penetration. 40% copper slag partial replacement enhanced the properties of self-compacting concrete, and up to 60% of fine aggregate can be substituted with industrial copper waste. By this investigation, copper slag can be used as a sustainable building material.

Comparative Study on Ultra High Performance Concrete with and Without Coarse Aggregate by Particle Packing Method

This study focuses on the comparative examination of ultra high-performance concrete with and without coarse aggregate using the particle filling method. This research study examines the rheological and mechanical properties of two high-performance concrete construction mixtures, one containing no coarse aggregate and the other containing coarse aggregate below 12.5 mm. The behavior of each mixture in its new state was examined by changing the water cement ratio as 0.26, 0.28 and 0.3. The two minerals used in the mixture are 10% micro silica and 5% metakaolin by weight instead of cement, and sand (M-Sand) and quartz sand produced as quality materials were used. Quartz sand 60 mesh, 100 mesh, 200 mesh etc. Available in colors. In order to prevent cracks in the concrete mixture and increase the ductility of the concrete, 1% steel fiber was used in both mixtures. Some properties of new ultra high-performance concrete (UHPC) were examined using a test rig frequently used to determine the properties of self-compacting concrete. Measure sufficient capacity, excess capacity and capacity of new functional concrete (UHPC). The samples are then cast and tested for compressive strength. It has been observed that the compressive strength of the composite material without coarse aggregate is 5% to 10% higher than that of the composite material with coarse aggregate.

Effect of waste PET fibre on rheological and mechanical properties of self-compacting concrete

Effect of waste PET fibre on rheological and mechanical properties of self-compacting concrete

Comparative Study on the Mechanical Properties of Steel Fiber Reinforced Self-Compacting Concrete

Self-compacting concrete (SCC) is a flowable concrete which can consolidate under its own weight without the need of external vibration. The highly fluid nature of SCC makes it suitable for placing in difficult environments like congested reinforcement and thinner sections. Use of SCC can also help in decreasing noise pollution at worksites which is caused by vibration of concrete. SCC is used in bridges, buildings, and tunnel construction. The addition of small closely spaced and uniformly dispersed fibres to concrete would act as a crack resistor and would substantially improve its properties. This type of concrete is known as fibre reinforced concrete. In fact, the fibre reinforcement mechanisms can convert the brittle behaviour of this cement-based material into a pseudo-ductile behaviour up to a crack width that is acceptable under the structural design point-of-view. Fibre addition, however, increases the complexity of the mix design process, due to the strong perturbation effect that steel fibres cause on fresh concrete flow. In the present study, the effect of steel fibres on fresh and hardened properties are studied by adding steel fibres of different percentages such as 0%, 1% and 2% for M70 grade of concrete. An experimental investigation has been carried out to determine different properties like workability and strength of Fiber Reinforced Self Compact Concrete and Self- Compacting Concrete (SCC). For testing the properties of SCC and Fiber Reinforced SCC (FRSCC) in fresh state slump-flow, T50 Test, L-box, U-box, and V-funnel tests were conducted. Whereas for testing the properties in hardened state compressive strength, split tensile strength and flexural strengths are carried out. Detailed studies have revealed that the Steel Fiber Reinforced Self Compacting Concrete made with the Steel fibres displays a better performance. The investigations and results are presented from the study. Index Terms: Self compacting concrete, Steel fibre reinforced concrete, Super plasticizer, Silica fume, Fly ash, Steel fibre.

Assessing the compressive and splitting tensile strength of self-compacting recycled coarse aggregate concrete using machine learning and statistical techniques

The construction industry is adopting high-performance materials due to technological and environmental advances. Researchers worldwide are studying the use of recycled coarse aggregates (RCA) as a partial alternative to natural coarse aggregates in concrete due to their sustainability and environmental benefits. This study compares the predictive abilities of three different machine learning techniques in evaluating the mechanical properties of 28-day-old self-compacting concrete (SCC) incorporating RCA to better understand how design parameters affect the mechanical properties of SCC containing RCA. The study used a range of statistical methodologies and machine learning algorithms, such as ANN, SVM, and M5P trees, to examine the relationship between design elements and accurately forecast the mechanical characteristics of concrete. The ANN model exhibited notable superiority in effectively forecasting compressive strength (CS) and splitting tensile strength (STS) compared to other models, with uncertainty bands of 15.038%− 21.154% for CS and 15.701%− 19.008% for STS. Moreover, all the uncertainties were under the threshold of 35%. Notably, the water-cement ratio emerged as the most crucial parameter in accurately predicting the mechanical properties of SCC. Finally, the parametric evaluation conducted revealed that CS and STS are inversely proportional to water-cement ratio and aggregate-cement ratio, whereas, are directly proportional to the water-binder ratio, and water-solids percentage.

Flexural Behaviour and Durability of Self Compacting Concrete Mixed with SN-Based Corrosion Inhibitor

The present study aimed to create a Self-Compacting Concrete (SCC) that possesses long-lasting properties and evaluate its fresh, mechanical, and durability properties by substituting 30% of the cement with class F fly ash. Furthermore, the performance of SCC that has been admixed with an SN-based corrosion inhibitor was investigated. Various factors such as the ratio of water to powder, fine aggregate, coarse aggregate (12mm downgraded), and the SN-based corrosion inhibitor were studied. The particle size distribution of the materials was analyzed using a sieve to achieve an even distribution of sizes, appropriate packing, and a lower void content. Multiple mixes were conducted, each with a unique combination of fine and coarse aggregate, as well as a water-to-powder ratio that was altered to optimize the mix percentage. Finally, controlled SCC (or mix M2) met the fresh property standards outlined in the EFNARC guidelines and specifications.The mechanical and durability properties of control SCC and SCC admixed with an SN-based corrosion inhibitor were investigated. Results showed a significant improvement in the compressive strength, split tensile strength, and flexural behavior of Reinforced Cement Concrete (RCC) beams when control SCC was utilized. Furthermore, the SCC with 2% SN demonstrated superior performance in terms of chloride penetration compared to the control SCC. The flexural strength parameters of the SCC with 2% SN were comparable to those of the control SCC. Based on the study's findings, it can be concluded that the addition of inhibitors at a weight percentage of 2% of the cement supplied increased durability properties without affecting the strength properties of SCC. Therefore, the created durable SCC can be recommended for applications such as bridges, prefabricated constructions, and deck slabs which are densely crowded with steel rebars. The study's findings could contribute to the development of SCC with enhanced properties, which would lead to more durable and sustainable construction materials.

Utilization of recycled coarse aggregate and high volume of GGBS in self-compacting concrete – an experimental study

Purpose The purpose of this study is to investigate the behaviour of M40 grade of self-compacting concrete (SCC) with high volume of ground granulated blast furnace slag (GGBS) (50%) and recycled concrete aggregate (RCA) content up to 100% to assess the mechanical properties of SCC. As per guidelines of IS: 383 – 2016, the RCA can be replaced up to 20% of natural coarse aggregate up to M25 grade of concrete. This study assesses the mechanical properties of SCC beyond 20% of RCA content. Based on the experimental investigations, the compressive strength of mixes decreases as the content of RCA increases. It is found that concrete mixes with 20% RCA and shows the maximum compressive strength at 56 days. Design/methodology/approach The fresh properties as per EFNARC and IS: 10262–2019 guidelines, ultrasonic pulse velocity testing, mechanical properties and microstructure analysis have been conducted to evaluate the performance of SCC with RCA for practical applications. Findings From the experimental investigations, it is found that up to 50% of recycled coarse aggregate can be used for structural applications. Originality/value The environmental pollution and dumping of waste on green land can be reduced by effective utilization of recycled coarse aggregate and GGBS in the production of SCC.

EFFECT OF BASALT FIBER ASPECT RATIO ON MECHANICAL AND WORKABILITY PROPERTIES OF SELF-COMPACTING CONCRETE

Self-compacting concrete (SCC) has become widely used thanks to its various advantages. SCC is also fiber reinforced, similar to conventional concrete. However, studies on SCC with fiber addition are limited. In this study, the effect of basalt fibers at different aspect ratios on the mechanical and workability properties of SCC was examined. Slump flow, V-funnel, compressive, flexural and splitting tensile strength tests were carried out within this study. Results showed that, although increasing the aspect ratio causes improvement in the workability properties of concrete, workability decreases compared to the reference SCC. Increases were observed in flexural and splitting tensile strengths with increasing aspect ratio. The compressive strength of the specimens that contains BF decreased compared to the reference sample because of the agglomeration effect. The results obtained were examined and discussed in detail.

Full-scale model test for the performance of DDS prestressed composite lining with SCC-NC of high internal pressure shield tunnel

To meet the requirements of structure design for high internal pressure with large diameter tunnel and long-distance concrete pouring, a Double-layered and Double-looped Steel-strand(DDS) prestressed composite lining with Self-Compacting Concrete (SCC) and Normal Concrete (NC) was presented. A series of SCC and NC properties tests were conducted to prepare optimal DDS prestressed concrete, followed by a standing full-scale loading test to demonstrate the features of deformation and bearing capacity for the composite lining. The results showed that the DDS combined bearing structure has good bearing capacity to internal pressure, where the bearing process was divided into three stages. In the elastic stage, there was no cracks appeared and the structure began to show a tensile trend with the increase of internal pressure. The structure entered the inelastic stage when the internal pressure reached 1.1 MPa, the cracks were found to initiate. As the internal pressure was increased to 1.3 MPa, the structure entered the crack propagation stage, where the expansion of cracks in the inner lining would lead to a stress redistribution. For the internal pressure from 0 to 1.45 MPa, the average proportion of internal pressure borne by the inner lining decreases from 80 % to 70 %, while the one by the outer lining increases from 20 % to 30 %. Our findings demonstrate the mechanical behavior of the optimized bearing structures and provide guidance for the design and construction in related tunnel engineering.

Properties of High-Content Micro-Steel Fiber Self-Compacting Concrete Incorporating Fly Ash and Slag Powder Performance Study

The addition or substitution of various gel materials in cement-based composites has been proven to be an effective approach in enhancing the performance of concrete. Current research focuses mainly on enhancing the toughness of concrete, but lacks discussion on the performance of alternative gel materials. Therefore, this study aims to explore the effects of partially substituting cement with fly ash and slag powder as gel materials, while incorporating a high volume fraction of micro-steel fibers (6%), on the workability and mechanical properties of self-compacting concrete. By means of rigorous experimental investigation and meticulous analysis, we comprehensively assessed the workability characteristics of self-compacting concrete, encompassing critical aspects such as filling ability, cohesion, and permeability. Additionally, we conducted an extensive evaluation of the mechanical attributes of self-compacting concrete, encompassing vital parameters, such as compressive strength, axial compressive strength, splitting tensile strength, and flexural strength. Last but not least, through a holistic integration of workability and mechanical properties, we conducted a comprehensive performance evaluation of self-compacting concrete incorporating a synergistic blend of fly ash, slag powder, and micro steel fibers. The experimental results indicate that the composite addition of fly ash and slag powder in self-compacting concrete, while compatible with up to 6% micro-steel fibers, leads to a decrease in concrete workability and an increase in cohesiveness due to the addition of micro-steel fibers. Moreover, fly ash predominantly influences the tensile properties of concrete, while the addition of slag powder significantly affects the compressive and flexural properties of concrete. Additionally, the addition of micro-steel fibers significantly improves the overall mechanical properties of concrete.

The effect of waste polyethylene terephthalate fibers on the properties of self-compacting concrete using Iraqi local materials

The effect of waste polyethylene terephthalate fibers on the properties of self-compacting concrete using Iraqi local materials

Effect of Cement kiln dust on some properties of self-compacting concrete

In the paper, Feasibility of preparing self-compacting concrete (SCC) was evaluated. Six mixes are designed to replace part of the cement with cement kiln dust (CKD). The first mix without replacement is the control mixt through which the rest of the mixtures are compared. As for the remaining five mixtures, part of the cement was replaced with CKD, and the replacement ratios are (2.5, 5, 7.5, 10, 12.5) % sequentially. Where the ratio of water to cement was constant is 0.3 in all mixes SCC. Then the viscosity, flow ability, passing ability and segregation properties of all mixes were examined, and then some mechanical properties (compressive resistance, dry density, ability of water absorption ) were examined for all mixes. The results indicate a decrease in the workability (passing ability, flow ability, and segregation) and mechanical properties (compressive strength and density) and also led to an increase in the viscosity of T500, as well as an increase in the water absorption ability of SCC. In general, the mechanical properties of some mixes are acceptable compared to the reference mix, especially when it is replaced by a few percentages

Influence of heavyweight aggregate on the fresh, mechanical, durability, and microstructural properties of self-compacting concrete under elevated temperatures

Recently, attention has been drawn to the production of heavyweight self-compacting concrete which combines the benefits of heavyweight concrete (HWC) and self-compacting concrete (SCC). This paper investigates the effect of using the barite coarse aggregate (size 4–8 mm) as substitution of volume of the natural coarse aggregate (size 4–8 mm) with various percentages (0, 20, 40, 60, 80, and 100%) on self-compacting concrete (SCC) properties. Slump-flow, T500 time, V-funnel, J-ring, L-box test, and fresh density were used to evaluate the fresh SCC characteristics. However, compressive strength, flexural strength, splitting tensile strength, water absorption, dry density, sulphate attack, and ultrasonic pulse velocity were used to evaluate the mechanical and durability characteristics. In addition, the impact of elevated temperatures (600 °C and 800 °C) on SCC containing various ratios of barite was studied through the evaluation of the density and compressive strength losses. Also, using fourier transform infrared radiation (FTIR) technique, mercury intrusion porosimetry (MIP), and scanning electron microscope (SEM), a microstructural investigation was conducted on hardened SCC containing various ratios of barite to determine the behaviour of barite in comparison to the control mix. The results demonstrate a slight negative effect on fresh and hardened of SCC properties with increasing percentages of barite. However, concrete incorporating up to 80% barite fulfilled all of the EFNARC-recommended criteria for SCC and the dry density of samples containing 80% barite was 2.660 kg/m3. Therefore, the self-compacting and heavyweight concrete characteristics were met by incorporating 80% barite as coarse aggregates. Nevertheless, the rate of increment in compressive strength increased with increasing barite ratios after exposure to 15 cycles of sulphate attack compared to the non-exposed samples.

Production of SCC Using Bagasse Ash as Fine Aggregate

Abstract: In this study an experimental investigation on production of self-compacting concrete with bagasse ash as partial replacement of fine aggregate is done. River sand has been partially replaced with bagasse ash from 0% to 80% by volume. Cement and fly ash is used as a powder material. Two concrete mixtures with cement content of 375 Kg/m3 and 500 Kg/m3 was proportioned. The workability properties such as slump flow, inverted flow, V-funnel flow time and J-ring flow were measured. The hardened properties such as density, compressive strength, split tensile strength, modulus of elasticity and flexural strength of concrete in each mixture were measured at various ages. Water absorption and weight loss ratio on drying of concrete was measured at 28 days. Micro structural properties such as SEM and XRD analysis were examined for SCC specimens.From the test results, it was found that (a) Workability properties depends upon the bagasse ash content (b) Partial replacement of BA up to 20% by volume of bagasse ash enhanced both the workability and hardened properties of self-compacting concrete (c) SEM micrograph images shows that irregular porous particles increases as BA increases and XRD pattern reveals that presence of silica peak increases as the BA content increases from 10% to 80%.

Utilization of industrial-based PVC waste powder in self-compacting concrete: A sustainable building material

Conventional experimental studies in concrete primarily focus on strength properties and microstructural analysis and ignore the environmental impacts of chosen waste in concrete. The present study addresses this critical research gap and uses industrial-based polyvinyl chloride (PVC) waste to demonstrate and meet the requirements of field practitioners and researchers. In the present study, various proportions of industrial-based PVC waste powder (PWP) (0–30%) by weight of cement were considered to partially replace cement in an M60 grade of self-compacting concrete (SCC). The first part of the study covers the fresh and strength properties of SCC, which was prepared using cement, sand, gravel, water, superplasticizer, SCM-like silica fume, ground granulated blast furnace slag, and PWP. In the second part of the study, the microstructure of various SCC mixes was investigated to understand the effects of PWP on the microstructure of the prepared SCC mixes. The optimum design mix for SCC was chosen based on extensive experimental and microstructural investigations. Further, a life cycle assessment was used to determine the influence of PWP on SCC usage from an environmental impact point of view for the optimized mixes. Considering all criteria, the results show that an SCC containing 5–10% PWP as a replacement for cement can be used. The present study establishes that using PWP in SCC is beneficial for the environment and can help lower the cost of SCC without compromising its strength and durability.

Effect of Fire Flame on Some Mechanical Properties of Self-Compacting Concrete

Effect of Fire Flame on Some Mechanical Properties of Self-Compacting Concrete

The Role of Xanthan Gum in Predicting Durability Properties of Self-Compacting Concrete (SCC) in Mix Designs

This study comprehensively investigates the rheological properties of self-compacting concrete (SCC) and their impact on critical parameters, including the migration coefficient, penetration depth of chlorine ions, specific electrical resistance, and compressive strength. A total of 43 mix designs were meticulously examined to explore the relationships between these properties. Quantitative analysis employed a backpropagation neural network model with a single hidden layer to accurately predict the resistant and durable characteristics of self-compacting concrete. The optimal number of neurons in the hidden layer was determined using a fitting component selection method, implemented in MATLAB software(2021b). Additionally, qualitative analysis was conducted using sensitivity analysis and expert opinions to determine the priority of research additives. The main contributions of this paper lie in the exploration of SCC properties, the utilization of a neural network model for accurate prediction, and the prioritization of research additives through sensitivity analysis. The neural network model demonstrated exceptional performance in predicting test results, achieving a high accuracy rate using 14 neurons for predicting parameters such as chlorine penetration depth, compressive strength, migration coefficient, and specific electrical resistance. Sensitivity analysis revealed that xanthan gum emerged as the most influential additive, accounting for 43% of the observed effects, followed by nanomaterials at 35% and micro-silica at 21%.