Self Compacting Concrete Research Papers (original) (raw)

Self- Compacting Concrete is a special type of concrete that is able to flow and compact under its own weight and can occupy all the spaces in the form without any vibration and at the same time it is cohesive enough to be handled without... more

Self- Compacting Concrete is a special type of concrete that is able to flow and compact under its own weight and can occupy all the spaces in the form without any vibration and at the same time it is cohesive enough to be handled without bleeding or segregation. In recent years, self-compacting concrete has been gaining wide range of application for placement in congested reinforced concrete structures with difficult casting conditions. For such applications, the fresh concrete must possess high fluidity and good cohesiveness. The use of additive materials such as industrial wastes as mineral admixtures can ensure the required concrete properties. The initial experimental study aims at producing and evaluating SCC for ternary blends incorporating fly ash, GGBS, sugarcane bagasse ash and alccofine as partial replacement of cement. Five number of SCC mixes were investigated in this study. The self-compacting mixes have cement replacement with different percentages of mineral admixtur...

This study examines an attempt to produce self-compacting concrete (SCC) containing fly ash (FA), ground granulated blast furnace slag (S) and both (FA+S). The effects of these materials on the rheological properties of the SCC mixes were... more

This study examines an attempt to produce self-compacting concrete (SCC) containing fly ash (FA), ground granulated blast furnace slag (S) and both (FA+S). The effects of these materials on the rheological properties of the SCC mixes were studied experimentally. The study began with three groups of SCCs, each with 25% water binder (w/b) and 550 kg/m3 total binder content. Instead of superplasticizers (SP), the chemical admixtures were lignosulphonates (LS), which replaced Portland cement (PC) at levels by weight of 10%, 20%, 30% 40%, 50%, and 60%. The fresh properties of the mixtures were examined experimentally for slump flow diameter, T50 time, V-funnel time, and L-box height ratio. In the mixtures with FA alone, a continuous decrease was observed in compressive strength. Increases in strength ended at 40% in the case of FA alone, and 30% for both the S and FA+S mixes. Statistical analysis was carried out to assess the effect of experimentally substituted materials FA and S, with results showing
that S had a greater influence than FA on T50 time, V-funnel, L-box height ratio, and compressive strength, while FA had more effect than S on the slump flow diameter test.

The current trend to decrease the clinker content in cements through the use of mineral additions in order to limit CO2 emissions into the atmosphere is of major concern for the precast industry as the resulting binders are generally not... more

The current trend to decrease the clinker content in cements through the use of mineral additions in order to limit CO2 emissions into the atmosphere is of major concern for the precast industry as the resulting binders are generally not very reactive at early ages. Here, composed cements (clinker+slag) or combinations between clinker and mineral admixtures are studied with a

The type and amount of filler are amongst the most important parameters influencing rheological, mechanical and durability characteristics of self consolidating concrete (SCC). Influence of using a limestone powder, the filler portion of... more

The type and amount of filler are amongst the most important parameters influencing rheological, mechanical and durability characteristics of self consolidating concrete (SCC). Influence of using a limestone powder, the filler portion of reactive basalt filler and a type of class C fly ash on the fresh properties, alkali–silica reactivity and transport properties were investigated in this study. For this purpose, six SCC mixtures having three filler types and two water/powder ratios were prepared. Alkali–silica reactivity was evaluated by conducting RILEM AAR-3 (38 °C) and AAR-4 (60 °C) concrete prism tests. Besides, the mixtures were exposed to permeable void content, sorptivity and chloride ion permeability tests in order to evaluate the transport properties. According to the results, using a high amount of powder from a reactive basalt in SCC mixture led to the highest expansion level and poor transport properties.

This paper presents a study on the use of different types of limestone and chalk powders as fillers in self-compacting concrete (SCC) and their effects on superplasticizer demand and the strength properties of concrete mixes. It was found... more

This paper presents a study on the use of different types of limestone and chalk powders as fillers in self-compacting concrete (SCC) and their effects on superplasticizer demand and the strength properties of concrete mixes. It was found that all the different limestone and chalk ...

Self compacting concrete (SCC) is one of the innovative construction material based on the performance in both fresh and hardened state. Due to over consumption of natural river sand deposits creating several environmental issues, as an... more

Self compacting concrete (SCC) is one of the innovative construction material based on the performance in both fresh and hardened state. Due to over consumption of natural river sand deposits creating several environmental issues, as an alternate manufactured sand (MSand) are being used as fine aggregate in place of natural river sand. This research is mainly concentrated on gradation of fine aggregate to get required quality by examine the effect of different fineness modulus (FM) of MSand (2.5, 2.7 and 2.9) on the mechanical properties of SCC with blending of binding materials as SCC_25FA_10SF; SCC_25FA_10SF and SCC_25FA_5SF_5MK. The test methods that were conducted are compressive strength and split tensile strength for curing periods of 7,28 and 90 days. Results showed that the strength values of SCC with FM value of 2.7 gave better results than other FM values. Hence, it is revealed that proper gradation of finer and coarser fractions of MSand has to be maintained to obtain desired strength in SCC at hardened state.

The aim of this paper is to assess the performance of self-compacting glass concrete (SCGC) after exposure to four elevated temperatures of 300 °C, 500 °C, 600 °C and 800 °C. The influence of curing conditions on the high temperature... more

The aim of this paper is to assess the performance of self-compacting glass concrete (SCGC) after exposure to four elevated temperatures of 300 °C, 500 °C, 600 °C and 800 °C. The influence of curing conditions on the high temperature performance of SCGC was also investigated. For each curing regime, five SCGC mixtures were prepared with recycled glass (RG) which was used to replace natural fine aggregate at the level of 0%, 25%, 50%, 75% and 100%. After exposure to the elevated temperatures, concrete mass loss, density, water porosity, ultrasonic pulse velocity (UPV) and water sorptivity were determined and then a compressive strength test was conducted. The test results indicate that regardless of the exposure temperature, all the water cured specimens had higher residual strengths and mass losses while the water porosity and water sorptivity values were lower as compared to the corresponding air cured specimens. The incorporation of RG in the concrete mixes helped to maintain the concrete properties after the high temperature exposure due to the melting and resolidification of the recycled glass in the concrete matrix.

The usage of an extensive group of industrial mineral residues (silica fume and fly ash) and other products significantly increases the rheological performance of concrete. This research is supposed to take a look at Rheology and... more

The usage of an extensive group of industrial mineral residues (silica fume and fly ash) and other products significantly increases the rheological performance of concrete. This research is supposed to take a look at Rheology and Strengthened Properties of Self Compacting Concrete with Silica fume. This examination commenced with 4 groups of Self Compacting Concrete changed with diverse probabilities of Silica fume (5%, 10%,15%, and 20%). The rheological properties of self-compacting concrete are investigated experimentally using the slump flow diameter, the U box test, the V funnel test, and the L box test. Compressive strength and flexural strength are the strengthened properties experimentally examined. In this study, we observed the suitable percent of silica fume, which offers advanced rheological characteristics of Self Compacting Concrete as equated to Conventional Self Compacting Concrete. Our experimental results show, by the replacing 15% of silica fume with the weight of cement will increase both Rheological Properties and strengthened Properties of SCC.

Self-consolidating concrete, also known as self-compacting concrete (SCC), is an innovative concrete that does not require vibration for placing and compaction. The mixture qualification process of Self Compacting Concrete consists from a... more

Self-consolidating concrete, also known as self-compacting concrete (SCC), is an innovative concrete that does not require vibration for placing and compaction. The mixture qualification process of Self Compacting Concrete consists from a small, well controlled laboratory batches are tested, second, the closest mixture/s is tested in production, which includes the use of batch mixing, and placing equipment, and finally a quality assurance/control plan for the fresh and hardened properties is developed. However, this paper presents a full research addressed only a small, well controlled laboratory batches and the laboratory testing phase of the mixture qualification process. For the purpose of study, a small, well controlled laboratory batches are tested using available locally aggregates in Sudan. Therefore, Slumpflow, V-funnel, L-box shape, J-ring, and Sieve stability tests of concrete mixtures were used to determine the flowability, passing ability and segregation resistance of SCC mixtures. The produced self compacting concrete is successfully confirmed the fresh properties of SCC with Slumpflow in range of 650 to 850 mm with high viscosity and excellent segregation resistance. The hardened properties of concrete were also considered and tested. The strength of SCC was found to be same or higher than that of normally vibrated concrete with the same constituent materials. SCC has relatively higher dynamic modulus of elasticity ranged between 38 to 42 GPa, in comparison to normally vibrated concrete for the same strength range of 50 to 60 MPa. Whereas the Spilt Tensile and Flexural strength of SCC are of 2.5 MPa and 10 MPa respectively. The major difficulty which was faced in development of SCC was on account of contradictory factors that the concrete should be fully flowable but without bleeding or segregation. It is required that the cement mortar of the SCC should have higher viscosity to ensure flowability while maintaining non-sedimentation of aggregates and that was achieved by using high content of powder (fine materials less than 0.15 mm includes cementitious materials). Achievement of durable concrete structures independent of the quality of construction work by using Self Compacting Concrete (SCC) has been proposed to solve the problem of the durability of concrete structures due to the gradual reduction of adequate compaction and skilled workers and for complex shape for the prestressed and precast industries in Sudan. The features of high benefit of fluidity and self consolidation will result in a variety of potential benefits for the end-user. Other benefits of the application of this new concrete technology require effort to be achieved. Moreover, areas such as quality control, mixture development, and logistics may need modification or expand resources when develop self-compacting concrete in Sudan.

Self-Compacting Concrete is a special type of concrete that is able to flow and compact under its own weight and can occupy all the spaces in the form without any vibration and at the same time it is cohesive enough to be handled without... more

Self-Compacting Concrete is a special type of concrete that is able to flow and compact under its own weight and can occupy all the spaces in the form without any vibration and at the same time it is cohesive enough to be handled without bleeding or segregation. In recent years, self-compacting concrete has been gaining a wide range of application for placement in congested reinforced concrete structures with difficult casting conditions. For such applications, the fresh concrete must possess high fluidity and good cohesiveness. The use of additive materials such as industrial wastes as mineral admixtures can ensure the required concrete properties. The initial experimental study aims at producing and evaluating SCC for ternary blends incorporating fly ash, GGBS, sugarcane bagasse ash and alccofine as partial replacement of cement. Five number of SCC mixes were investigated in this study. The self-compacting mixes have cement replacement with different percentages of mineral admixtures while keeping cement quantity fixed for 360kg/m 3 .The tests such as slump flow test, V funnel test, T500 slump flow test, J ring test, and V5min test were carried on fresh properties of SCC mixes to check the prerequisites mentioned in EFNARC, the mechanical properties of hardened concretes such as compressive strength, split tensile strength were also carried on all the mixes. Incorporating these mineral admixtures resulted in producing economical concrete and the workability requirements of SCC were satisfied, the strength obtained was maximum when alccofine and GBBS were added in the concrete.

Flowability, passing ability and stability are important properties to be considered while designing a robust self-compacting concrete (SCC). The simulation of SCC provides a useful tool for ensuring a robust SCC mix for construction and... more

Flowability, passing ability and stability are important properties to be considered while designing a robust self-compacting concrete (SCC). The simulation of SCC provides a useful tool for ensuring a robust SCC mix for construction and formwork design. Hence, this paper presents the results of a 2D computational fluid dynamics (CFD) simulation carried out on the slump flow and L-box tests to evaluate the flowability and passing ability of an SCC made with limestone powder (LSP). The Herschel-Bulkley viscosity model is used for modeling the behavior of the fresh concrete. The result obtained shows a good correlation between the numerical simulation and the experimental results.
Another phenomenon studied in the paper is the formwork pressure due to SCC. Application of a new finite element model developed by the authors is proposed here for studying the evolution of lateral pressure in self-compacting concrete, incorporating factors such as the casting rate and the evolution of rheological properties of SCC. The proposed finite element simulation of SCC formwork pressure shows a good correlation with available experimental results from the literature.

SCC Guide lines by EFNARC

This article addresses to the issue of durability related properties of self-compacting concrete (SCC) with the use of coarse recycled aggregates obtained from demolition of concrete structures. The objective was to verify the influence... more

This article addresses to the issue of durability related properties of self-compacting concrete (SCC) with
the use of coarse recycled aggregates obtained from demolition of concrete structures. The objective was
to verify the influence of recycled aggregates on SCC permeability properties. For this purpose four
different types of concrete mixes were produced, one of them used as reference with natural coarse
aggregates and the others prepared with 20%, 40% and 100% of recycled coarse aggregates. The properties related to the durability of SCC, as air and water permeability and capillary absorption were determined on concrete specimens with and without preconditioning. The results from fresh and hardened concrete
properties lead to the conclusion that it is viable to replace natural coarse aggregates by recycled coarse aggregates since the present research does not show any detrimental to the SCC permeability properties.

A robust self compacting concrete (SCC) is characterized by its flowability, passing ability and stability. Numerical simulation of SCC is a valuable tool, which can be used as a means to model and predict concrete workability and to... more

A robust self compacting concrete (SCC) is characterized by its flowability, passing ability and stability. Numerical simulation of SCC is a valuable tool, which can be used as a means to model and predict concrete workability and to tailor its rheological properties. The simulation of SCC flow could be used for obtaining optimum rheology of the mix to ensure its mobility and segregation resistance during placement. This paper presents the results of numerical simulation of SCC flow using a 2-D computational fluid dynamics (CFD) framework. The commercial CFD software ANSYS/FLUENT was used to perform 2-D simulation of slump flow and L-box tests. The Herschel-Bulkley viscosity model is used for modeling the behavior of fresh concrete. SCC mixes with silica fume as mineral additives was simulated. A good correlation between the numerical simulation and the experimental results is obtained.

The present study investigates the performance of self-compacting concrete (SCC) and self-compacting sand concrete (SCSC) incorporating recycled concrete fines and aggregate under different sulphate environments. Similar mixtures... more

The present study investigates the performance of self-compacting concrete (SCC) and self-compacting sand concrete (SCSC) incorporating recycled concrete fines and aggregate under different sulphate environments. Similar mixtures incorporating natural aggregates and natural pozzolana were also tested for comparison. Different sulphate attack regimes (i.e. fully submerged and immersion-drying cycles) were applied. Compressive strength development/degradation under sulphate attack was monitored for all tested mixtures. Results indicate that the use of recycled materials did not significantly affect the strength development with respect to mixtures with natural materials. Moreover, mixtures incorporating recycled concrete aggregate and fine recycled concrete exhibited a better sulphate resistance behaviour than those with natural aggregates and natural pozzolana. In conclusion, the quality of the used recycled materials is a key factor in producing green and sustainable self-compacting...

Corrosion initiation time of embedded steel is an important service life parameter, which depends on concrete material make-up, exposure environment, and duration of exposure. Early and accurate determination of corrosion initiation time... more

Corrosion initiation time of embedded steel is an important service life parameter, which depends on concrete material make-up, exposure environment, and duration of exposure. Early and accurate determination of corrosion initiation time will aid in designing durable reinforced concrete, saves cost and time. This study leveraged on the power of ensemble machine learning by combining the performances of different models in estimating the corrosion initiation time of steel embedded in self compacted concrete using corrosion potential measurement. The concrete specimens were prepared with limestone powder as supplementary addition to Portland cement and was exposed to 5% sodium chloride in accordance with the requirements of ASTM C876-15 for 8 months. During the exposure, corrosion potential of the embedded steel was measured, and the recorded datasets were used in training five different machine learning models. With cement, limestone powder, coarse aggregate, fine aggregate, water and exposure period.as input variables, five different models were developed to estimate the corrosion initiation time (determined from the corrosion potential measurements) of the embedded steel. With respect to model predictive performance, the acquired results demonstrated that the random forest (RF) ensemble model amongst other trained models performed best with 85/15 dataset percentage split for the training and testing. RF ensemble performed best with CC and RMSE of 99.01% and 18.2747 mV for training, and 98.67% and 25.0298 mV for testing respectively. Hence, due to its superior and robust performance, this study proposes RF ensemble model in the estimation of corrosion initiation time of embedded steel in reinforced limestone-cement blend concrete.

Self-compacting concrete (SCC) is becoming a popular choice in concrete industry dye to ease of placement in congested reinforcements, reduced labor and equipment, no segregation character and smooth surface. Fly ash has been used in... more

Self-compacting concrete (SCC) is becoming a popular choice in concrete industry
dye to ease of placement in congested reinforcements, reduced labor and equipment,
no segregation character and smooth surface. Fly ash has been used in producing SCC
which increases filling and passing ability of concrete. The present study was carried
out to check the optimum dosage of super plasticizer which influence on fresh
properties of self-compacting concrete, the super plasticizers are varied from 0.5% to
1.75%. And also to check the fresh and hardened properties of sisal fiber reinforced
SCC with different percentage of fiber addition. The materials were mixed with 0.25%,
0.5% and 0.75% addition of fiber in M30 mix design and casted in cubes, beams and
cylinders. The obtained specimens were subjected to test the compressive, flexure and
split tensile strength. Compressive, flexure and split tensile strengths of the specimens
were analyzed for 7 and 28 days of curing.

The cement and fine aggregate are the most commonly used materials for concreting, plastering and masonry work. The use of Metakaolin can be used as a partial replacement material for cement in the production of concrete where service... more

The cement and fine aggregate are the most commonly used materials for concreting, plastering and masonry work. The use of Metakaolin can be used as a partial replacement material for cement in the production of concrete where service environments, exposure conditions or life cycle cost considerations define the use of Self Compacting concrete. Metakaolin is used in concretes to improve the compressive, flexural strength and reduces the permeability of the hardened concrete. In this paper an overview on the literature on mechanical and durability behaviour of self-compacting concrete with partial replacement of cement by metakaolin is carried out based on recent research studies

Les bétons autoplaçants (BAP) s'écoulent sous l'effet de leur poids propre sans recours à aucune vibration, cette propriété nécessite une très grande fluidité (sans risque de ségrégation) en incorporant dans le béton une quantité élevée... more

Les bétons autoplaçants (BAP) s'écoulent sous l'effet de leur poids propre sans recours à aucune vibration, cette propriété nécessite une très grande fluidité (sans risque de ségrégation) en incorporant dans le béton une quantité élevée de fines, et en réduisant le rapport E/P par l'introduction des superplastifiants. La qualité des granulats est un paramètre très important, elle influe sur les propriétés rhéologiques et mécaniques des bétons. Cette étude traite l'influence du sable de dune en guise de granulat fin (un sable caractérisé par son homométrie, sa nature siliceuse, sa finesse et sa surface spécifique très élevée exigeant ainsi une importante quantité d'eau de gâchage pour leur mouillage), en variant le rapport E/C (0.50 et 0.55) et par l'introduction d'un superplastifiant présentant plusieurs dosages (1%, 1.5%, 1.75% et 2%). Les résultats obtenus montrent que la maniabilité des BAP est améliorée par l'ajout des superplastifiants, par contre les résistances mécaniques sont affectées. 1. Introduction Le BAP peut être considéré comme un matériau de haute performance, qui s'écoule sous l'effet de son poids propre sans recours à aucune vibration mécanique. Cette mise en place sous seul effet de la gravité, nécessite une très grande fluidité des matériaux mais il est aussi indispensable que le béton conserve une stabilité satisfaisante et une parfaite homogénéité. Ces deux propriétés sont obtenus par une quantité élevée de particules fines, Un rapport (Eau/Poudre) faible et un dosage élevé de super plastifiant et d'un agent stabilisateur de viscosité [1, 2, 3]. Les BAP formulés dans le monde sont très riches en quantité cimentaire, par conséquent, la teneur importante du ciment provoque un accroissement de la température des bétons due à la chaleur d'hydratation et engendre en plus l'augmentation de son prix. Il est raisonnable donc de remplacer une partie du ciment par un ajout minéral tel que : le laitier du haut fourneau, la pouzzolane ou les fillers calcaires [4, 5]. Le sable est le constituant inerte entrant dans la composition des mortiers et des bétons, son utilisation permet d'assurer une continuité granulaire entre le ciment et le gravier afin d'obtenir un squelette plus résistant et plus compact. Les études faites sur les sables de dunes dans les dernières décennies, sont multipliées afin de quantifier les caractéristiques physico – chimiques de ce genre de sable qui est, d'origine éolienne, caractérisé par sa finesse, son horométrie et son diamètre maximal qui n'excède pas 5 mm. Les grains de ce sable sont de forme arrondie où anguleuse et visibles à l'oeil, se caractérisent par une porosité inter granulaire et une surface spécifique élevées [6, 7]. Ces propriétés spécifiques vont jouer un rôle majeur dans les caractéristiques du béton à l'état frais et durci : maniabilité médiocre, compacité réduite et résistance mécanique affectée [8]. L'augmentation du taux de sable de dune dans le mélange de béton fait accroître la demande en eau en comparaison avec un béton

This paper proposes a mix design procedure for self-compacting concrete (SCC) to achieve target mean compressive strength, in which mixes are designed on the basis of Indian Standards and suitable adjustments are done as per the previous... more

This paper proposes a mix design procedure for self-compacting concrete (SCC) to achieve target mean compressive strength, in which mixes are designed on the basis of Indian Standards and suitable adjustments are done as per the previous studies and guidelines provided by various concern agencies. The amount of fine and coarse aggregates, cementing material and mixing water, as well as type and dosage of super plasticizer (SP) to be used are the major factors influencing the properties of SCC in the plastic stage as well as in hardened stage. So in plastic stage slump flow, V-funnel, L-flow, and in hardened stage compressive strength, splitting tensile strength and flexural strength tests at the age of 28 days were carried out to observe the performance of SCC, and the results indicate that the proposed method could produce successfully SCC of high quality. For M30 grade obtained mean compressive strength was 39.13 MPa.

Research findings have reported a behavioural relationship between the splitting tensile strength and compressive strength of concretes. This work studied both the experimental and analytical relationships that exist between splitting... more

Research findings have reported a behavioural relationship between the splitting tensile strength and compressive strength of concretes. This work studied both the experimental and analytical relationships that exist between splitting tensile strength and compressive strength of both vibrated concrete (VC) and self compacting concrete (SCC) of similar grades. Both concrete types were designed to achieve target compressive strength of 20 N/mm 2 , 30 N/mm 2 and 40 N/mm 2 at 28 days. The compressive and splitting tensile properties were measured on cylindrical concrete specimens of 150 mm diameter  300 mm length at 28-days using a compression testing machine. The analytical work tested seven different reported models relating the two measured parameters for VC on SCC, while the Welch 2 sample t-test statistical technique was adopted to check the normality and equality of variance of the results. Experimental findings revealed that the ratio of the splitting tensile to compressive strengths for VC and SCC decreases with increasing compressive strength, and the analytical study revealed that similar analytical model could be adopted for both concrete types as there is no statistically detectable difference between their results.

Fly ash released from the thermal power plants constitutes a major portion than bottom ash. As a major portion of the coal ash, fly ash has been recognized widely as a source material for geopolymers while the utilization of bottom ash... more

Fly ash released from the thermal power plants constitutes a major portion than bottom ash. As a major portion of the coal ash, fly ash has been recognized widely as a source material for geopolymers while the utilization of bottom ash has received very less attention. In order to promote greater usage of bottom ash in construction, this paper focuses on the study of ground bottom ash in geopolymer mortar. The effect of molar ratio of SiO 2 /Na 2 O, Na 2 SiO 3 /NaOH ratio and curing mode were considered on compressive strength of bottom ash based geopolymer mortar. Molarity of sodium silicate solution was maintained as 8M. Ambient curing and steam curing at 60ºC was attempted. Test results indicate that Na 2 SiO 3 /NaOH of ratio 2 with SiO 2 /Na 2 O molar ratio 1 mortar achieved higher compressive strength under both ambient curing and steam curing.

The study has conducted to determine the workability and compressive strength of the self –compacting concrete. The sand has replaced with quarry dust with the proportion of 10, 20, 30 and 40% and super plasticizer was added 0.9%. The... more

The study has conducted to determine the workability and compressive strength of the self –compacting concrete. The sand has replaced with quarry dust with the proportion of 10, 20, 30 and 40% and super plasticizer was added 0.9%. The experiments were carried out at the Infrastructure University Kuala Lumpur (IUKL) concrete laboratory. Slump flow, J-Ring tests were carried out to determine the workability of self-compacting concrete and compressive strength test was conducted on 7 days and 28 th days of curing period. A finding of the study shows that workability and compressive strength has increased by addition of quarry dust. It is concluded that addition of quarry dust up to 30% improve the workability of the self-compacting concrete and further addition of quarry dust decrease the workability. Additionally, compressive strength of the quarry dust modified self-compacting concrete shows the trend of higher compressive strength up to 30% addition of quarry dust with sand replacement and further addition decrease the compressive strength.

Concrete has high compressive strength, but is remarkably weak in tension (about one-tenth its compressive strength), and as such, is usually reinforced with materials that are strong in tension. In the presence of reinforcement, the... more

Concrete has high compressive strength, but is remarkably weak in tension (about one-tenth its compressive strength), and as such, is usually reinforced with materials that are strong in tension. In the presence of reinforcement, the tensile load is transferred to the reinforcing material. An alternative to increasing the load carrying capacity of concrete in tension is the addition of fibres. Well-dispersed fibres in the concrete act to bridge the cracks that develop in concrete. The incorporation of fibres in a cement matrix leads to an increase in the toughness and tensile strength, and an improvement in the cracking and deformation characteristics of the resultant concrete. Sisal fibre is derived from the leaves of the plant. It is usually obtained by machine decortications in which the leaf is crushed between rollers and then mechanically scraped. The present study was carried out to check the fresh and hardened properties of sisal fiber reinforced self-compacting concrete with different percentage of fiber addition. Degree of workability of concrete mix with 0.2% super plasticizer and water cement ratio 0.31 had good workability which is effective, was obtained. Materials were hand mixed with 0.5%, 1% ,1.5% and 2% addition of fiber in M40 mix design and casted in cubes and cylinders. The super plasticizers are used in different percentages like 0.15%0.2%,1%&2%. The obtained specimens were subjected to test the compressive and split tensile strength. And the compressive and split tensile strengths of the specimens were analyzed after 7days and 28days of curing.

Prezenta lucrare aduce contribuții legate de fenomenul de aderenţă dintre betonul autocompactant şi armătură. Principalul obiectiv al programului experimental a fost studierea fenomenului de aderenţă dintre betonul autocompactant şi... more

Prezenta lucrare aduce contribuții legate de fenomenul de aderenţă dintre betonul autocompactant şi armătură. Principalul obiectiv al programului experimental a fost studierea fenomenului de aderenţă dintre betonul autocompactant şi barele de armătură, mai precis a efectului confinării betonului cu armătură transversală, pentru validarea sau îmbunătăţirea modelelor teoretice existente.

high flowability and resistance to segregation and bleeding. The use of fine materials such as silica fume and Viscosity Modified Agent (VMA) can ensure the required concrete properties for SCC. This study presents information regarding... more

high flowability and resistance to segregation and bleeding. The use of fine materials such as silica fume and Viscosity Modified Agent (VMA) can ensure the required concrete properties for SCC.
This study presents information regarding development, properties and advantages of using High Strength SCC in the construction industry. This research was carried out to establish the fresh properties and hardened properties of SCC. The high strength SCC is obtained by using 53 grade Ordinary Portland Cement (OPC), Silica fume and super plasticizer - GLENIUM B233.
The mix design is derived from specifications given in the EFNARC guidelines (May 2005). The mix proportions of the constituents are rearranged by many trials in the aim of obtaining high strength concrete of compressive strength above 60 MPa. The mix proportions are checked for workability from tests like slump flow, U box, L box, J ring and V funnel.
Tests on hardened concrete such as Compressive test, Split tensile test and Flexural Test have been done. The Compressive strength of cured specimens has been tested on 7, 14, 28 days. Specimens were cast in two different shapes, Cubes of size 150 mm and cylinders of diameter 150 mm and height 300 mm. The experimental results reveal that the proposed mix

An attempt was carried out to develop some properties of self-compacted concrete (SCC) by adding waste plastic fibers (WPF) resulting from cutting beverage bottles. Many tests were conducted to investigate the effect of adding WPF on the... more

An attempt was carried out to develop some properties of self-compacted concrete (SCC) by adding waste plastic fibers (WPF) resulting from cutting beverage bottles. Many tests were conducted to investigate the effect of adding WPF on the fresh properties, whereas other tests were applied on that kind of concrete to study the effect of this type of waste on hardened properties. For this reason, different self-compacting concrete mixtures were designed at constant water-to-binder ratio of 0.35 and 490 kg/m3 of binder content. The class F fly ash was replaced with cement as 25% by weight. The eighth designated plastic fiber contents of 0, 0.25, 0.5, 0.75, 1, 1.25, 1.5, 1.75 and 2% by volume. The workability properties of self-compacting concrete mixtures were performed to slump flow diameter, T50 slump flow simultaneously, V-funnel flow at the same time, and L-box height ratio. The 7,14 and 28-day compressive strengths of self-compacting concretes were also measured. Moreover, the 7, 14 and 28-day flexural strengths of concretes were also measured. The test results showed that the plastic fibers have adverse effect on the fresh properties of self-compacting concrete and improvement by hardened properties.

Millions of tons of spent garnet, a by-product of surface treatment operations, are disposed of every year in landfills, oceans, rivers, and quarries, among others, thus causing environmental problems. The main objective of this study is... more

Millions of tons of spent garnet, a by-product of surface treatment operations, are disposed of every year in landfills, oceans, rivers, and quarries, among others, thus causing environmental problems. The main objective of this study is to evaluate spent garnet as a sand replacement in concrete prepared with ground granulated blast furnace slag (GGBS)-based self-compacting geopolymer concrete (SCGC). Concrete mixtures containing 0%, 25%, 50%, 75% and 100% spent garnet as a replacement for river sand were prepared with a constant Liquid/Binder (L/B) mass ratio equal to 0.4. Compressive, flexural and splitting tensile strengths as well as workability tests (slump, L-box, U-box and T50) were conducted on concrete containing spent garnet. As per specification and guidelines for self-compacting concrete (EFNARC) standard, the test results showed that the concrete's workability increased with the increase of spent garnet, while all the other strength values were consistently lower than conventional concrete (SCGC) at all stages of replacement. Based on the outcomes It is recommended that spent garnet should be used in concrete as a sand replacement up to 25% to reduce environmental problems, costs and the depletion of natural resources.

The construction of modern structures alarming the attention of use of materials with improved properties in respect of strength, stiffness, toughness and durability. Concrete is one of the most widely used construction material having... more

The construction of modern structures alarming the attention of use of materials with improved properties in respect of strength, stiffness, toughness and durability. Concrete is one of the most widely used construction material having several advantages such as high strength, good mould ability and high durability. The major disadvantages of concrete are its poorer tensile strength and lesser ductility (toughness). Conventional concrete used in building construction and engineering applications requires compaction to attain strength, durability and homogeneity. The typical method of compaction, by vibration, generates delays and additional costs in projects and could pose a serious health hazard due to noise pollution in and around construction sites. Self Compacting Concrete (SCC) is a concrete which is highly flowble, can flows readily into place, fill the formwork without any compaction and without undergoing any significant segregation. Recycling is the act of processing the used material for creating a new useful product. Construction and Demolished waste also generate Recycled Aggregate (RA). Such a Recycled Aggregate proved to be a reliable alternative to Natural Aggregates (NA) in concrete. There is a growing need for renovation from a usual consumption based society to a sustainable society owing the natural environment pollution, exhaustion of natural resources and as decreasing capacity of disposal facilities for final waste. Use of aggregates from Building Demolished Waste (BDW) in structural concrete is definitely an important stride. Use of RA in developing SCC is certainly a novel thought towards achieving a sustainable concrete. There is a pressing demand for the use of Recycled Aggregate in recent concretes, as sustainability is given the highest importance in today’s world. This has necessitated the make use of Recycled Aggregates in SCC and fibre based SCC. Hence Reinforced Self Compacting Concrete using Recycled Aggregate with fibres may be a potential material in construction. In order to clearly understand the performance of such a concrete, there is a call for to study the stress-strain and flexural strength behaviour. The present study focuses on flexural bond strength behaviour of Fibre Reinforced Self Compacting Concrete by replacing the natural Aggregate with Recycled Aggregate. BDW is used as coarse aggregate in the concrete, with an aim to achieve sustainable concrete.

Self-Compacting concrete is a type of concrete that gets compacted under its self-weight. It’s commonly abbreviated as SCC and defined as the concrete which can placed and compacted into every corner of a formwork; purely means of its... more

Self-Compacting concrete is a type of concrete that gets compacted under its self-weight. It’s commonly abbreviated as SCC and defined as the concrete which can placed and compacted into every corner of a formwork; purely means of its self-weight by eliminating the need of either external energy input from vibrators or any type of compacting effort. In this study, the effect of replacing the cement by limestone powder with (5%,10%,20%) respectively and steel fibers (2%) their combinations of various proportions on the properties of Self compacting concrete has been compared. Properties of compressive strength, split tensile strength and flexural strength of Concrete were determined. However, the results of this study suggest that limestone powder (10%),steel fibers (2%) combinations can improve the workability of Self compacting concrete, more than conventional concrete and while their using separate. Limestone powder can have a positive influence on the mechanical performance at early strength development while Steel fibers can improve more strength avoid cracking. Rapid chloride permeability test for conventional concrete and optimum one i.e. of replacement of cement by Limestone powder (10%) and steel fibers (2%) with self compacting self curing concrete gets moderately so results suggest that we can use for construction purpose. For slab self-curing is more workable than normal curing.

In this paper an attempt has been made to study the use of used foundry sand and waste tyre rubber on properties of Self-Compacting-Concrete (SCC) is carried out. Replacement of sand with used foundry sand as 10%, and 15% and replacement... more

In this paper an attempt has been made to study the use of used foundry sand and waste tyre rubber on properties of Self-Compacting-Concrete (SCC) is carried out. Replacement of sand with used foundry sand as 10%, and 15% and replacement of coarse aggregate with waste tyre rubber as 5% and 10% is investigated. The results show that that utilization of used foundry sand and waste rubber tyre will increase the strength of the self-compacting concrete when compared with conventional concrete. But it should not exceed 15% of used foundry sand and 10% of waste tyre rubber.

In this paper the properties of Self Compacting Concrete (SCC) was investigated using white cement and lime stone powder as fine aggregate instead of sand. All mixtures were proportioned with constant amount of (cement, lime stone powder,... more

In this paper the properties of Self Compacting Concrete (SCC) was investigated using white cement and lime stone powder as fine aggregate instead of sand. All mixtures were proportioned with constant amount of (cement, lime stone powder, coarse aggregate and silica fume). While the glass powder, ceramic powder and glue were used as additives in different proportions from cement weight. The study focuses on comparison of fresh properties for self compacting concrete using two types of testing flow test and J-ring test. Whereas the hard concrete properties tests limited to compressive strength.
The results leading to some developing in fresh properties and hard properties of self compacting concrete due to adding the additives. The best spread ability obtained at adding glue (4%) from cement weight. While the glass powder and ceramic powder affect to hard properties, adding ceramic powder increased the compressive strength at rates between (10-20) % from cement weight and adding glass powder modified the compressive strength at rates more than (20)% from cement weight.