Papers by Keyword: Self-Compacting Concrete (SCC)

Abstract: Vibrated concrete (VC) and self-compacting concrete (SCC) have a substantially different composition, resulting in dissimilar mechanical properties regarding cracking behaviour. The critical value of the mode I stress-intensity factor K_IC is an appropriate fracture parameter for evaluating fracture toughness and can be obtained from three-point bending tests (3PBT) on small, notched specimens. Subsequent determination of the energy release rate thus allows to examine the crack propagation and fracture process of both concrete types. This paper describes the results of such 3PBTs on samples, made from VC and SCC. Evaluation of the cracking behaviour, derived from these results, reveals remarkable differences.

Abstract: Currently, the SCC is already used in several countries and is considered a breakthrough in the building process of concrete structures, as it increases productivity, reduces the demand for labor, work in time of concreting and improves the quality of the concrete and the environment work. Innumerous investigations on SCC [,[,[,[ have been developing in order to know their behavior, improve their properties and applicability in different structural elements. This paper presents the implementation of the SCC in the execution of the base of the waters reservoir, in water treatment station.

Abstract: Waste residues derived from the breaking process of rocks have been many times inadequately discarded on the environment generating an environmental passive. The residues could be used in the production of self-compacting concrete (CAA) providing more sustainable constructions. To study different CAA mixtures the following tests have been performed in the fresh state: Water Absorption, L - Box, V - Funnel and Slump Flow Test. For the evaluation of mechanical performance, the concrete Compression Strength Test, Flexural Strength Test and Tensile Strength by Diametric Compression Test have been performed in the hard state. Technical and environmental viability in the addition of this type of residue for the studied percentages have been verified.

Abstract: The influence of mineral admixtures on workability of fresh concrete and chloride ion permeability resistance of hardened concrete for C50 self-compacting concrete was investigated by means of the Natural Immersion Test. The results showed that the chloride diffusion coefficient in fly ash concrete decreased first and then increased with increasing fly ash content in cementitious materials, when fly ash content was 30% or 40%, it got the lowest value at 28 days or 90 days, respectively. The chloride diffusion coefficient in specimens decreased with increasing the ground granulated blast furnace slag content in cementitious materials, but it changed little when the replacement was in ranges of 50% to 60%. Furthermore, for the specimens which replaced by fly ash and ground granulated blast furnace slag, the chloride diffusion coefficient decreased first and then increased with increasing the fly ash content in complex cementitious, and when fly ash content was 10% or 20%, it got the lowest value at 28 days or 90 days, respectively.

Abstract: With the powerful regression and fitting of support vector machines in uncertainty and the non-linear,based on the determination of the content of the coarse aggregate and characteristic parameters, this paper established a predictive model of self-compacting concrete elastic modulus based on support vector machine.Through analysis and comparison with experimental results, it proves the accuracy and effectiveness of the model.

Abstract: Self-compacting concrete (SCC) is a flowing concrete mixture that is able to consolidate under its own weight. The highly workable nature of SCC makes it suitable for placing in complex structural elements and in sections with congested reinforcement. Utilization of industrial waste products in the construction industry draws serious attention of many researchers and investigators. In this study an experimental investigation has been carried out to study the significance of blast furnace slag as partial replacement for coarse aggregate in fly ash blended self-compacting concrete. The coarse aggregate was replaced by blast furnace slag at 10% to 100% and various tests were conducted to determine the optimum level of replacement of blast furnace slag in self-compacting concrete. The specimens were subjected to compressive strength, split tensile strength and flexural strength tests in addition to fresh concrete properties. Slump flow, J-ring test, L-box, U-box and V-funnel tests were carried out for evaluating fluidity, filling ability and segregation properties of the fresh concrete. Based on the overall observations it could be concluded that an increase in slag proportion increases the strength properties and among the various percentages of replacement 30% is found to be optimum for maximum strength properties.

Abstract: This paper primary researched the influence of limestone powder on the workability, the strength performance and the volume stability of self-compacting concrete (SCC). Results showed that the workability of self-compacting concrete was improved greatly by mixing proper limestone powder; besides, limestone powder could improve early age strength of concrete obviously, but had little influence on long age strength; the self-shrinkage of concrete increased as the admixture of limestone powder increased. The content of limestone should be capped at 10% and the optimum mix amount is about 7%.

Abstract: Self-compacting concrete(SCC) is the current trend of new concrete.A variety of materials have been added in it on the purpose of changing the properties of SCC[1].In this paper,three viscous materials of limestone powder, silica fume and metakaolin have been added in SCC to change self-compactability and strength.

Abstract: One of the effective ways of low carbon concrete is to reduce the cement content. It can not only reduce the greenhouse gas emission, but also improve the comprehensive utilization of industrial solid waste. In this paper, the mix design and experimental research of C15 Self-Compacting Concrete (SCC) were carried out by substituting cement with high volume fly ash. A partition coefficient of environmental burden Cm was introduced in order to assess the environmental effect of different mix proportion SCC precisely by using life cycle assessment method. Evaluation results showed that the mixing of fly ash can reduce the consumption of coal, the discharge of CO2 and the solid wastes effectively. The study provided a rational basis for the high performance and low cost fly ash concrete.

Abstract: The influence of complex admixture on chloride diffusion coefficient of C50 self-compacting concrete for marine environment was investigated by means of the NT BUILD 443 Test, and the influence mechanism of complex admixture on the diffusion coefficient was studied, respectively. The results showed that the chloride diffusion coefficient decreased first and then increased with increasing the fly ash content in complex cementitious, and when fly ash content was 10% or 20%, it got the lowest value at 28 days or 90 days, respectively. Its more helpful to promote the fly hydration degree for extending curing period. Furthermore, the porosity and average pore size decreased first but then increased with increasing the fly ash content in complex cementitious, the porosity and average pore size got the lowest value when the fly ash content was 20% in cementitous.