Papers by Keyword: Steel Fiber

Abstract: This report outlines the results of an experimental study conducted on the effects high temperatures have on changes in linear sizes, mass, and density of steel fiber concrete containing fiber with varying durability, types, diameter, and percentages by volume. After being exposed to heat, the steel fiber concrete reduces in linear size, as well as decreasing in mass and density. Changes are seen as a result of rising temperatures between 20-1100 °С The impact on the change in mass, size and density of the quantity and type of fiber is not unambiguous, it does not fully correspond to the theoretical concepts considered in the work and require additional research.

Abstract: Pervious concrete pavement is a porous urban surface. It could reduce runoff capacity, decrease a storm-water detention, reduce the amount of requiring rain drainage pipes, and let rainwater filter into ground and allow groundwater resources to renew in time. Fire damage, could be one of important factors since European countries have been used pervious concrete in buildings construction. This study was conducted to assess the fire damage on pervious concrete with silica fume and steel fiber. The test results find that pervious concrete with 10% silica fume and 2% steel fibers showed the maximum increase in compressive and flexural strengths by 60% and 23% respectively over the control mix while maintaining adequate permeability. It also shows that the flexural strength of pervious concrete with 10% silica fume and 2% steel fiber could reach 45 kg/cm² strength specification. The high temperature exposure results find that pervious concrete could hardly be detected any crack at the temperature of 700 °Cor 800°C and fire duration of 2 hours. There is some damage on strength after the fire-attack test, the ratio of the residual strength can range from about 20%~60% and it depends on temperature, steel fiber, and silica fume content. By this study of pervious concrete will be valuable for fire safety design and construction of practice.

Abstract: Self-compacting steel fiber concrete must meet the strength standard after steel fiber is added and must have good fluidity. The test results show that the addition of steel fiber to concrete will affect the fluidity of concrete. Compared with ordinary concrete, the addition of steel fiber will improve the compressive strength and flexural tensile strength of concrete to varying degrees. The mix proportion test can be carried out in stages, i.e. the mix proportion meeting all performance indexes used is determined first, then steel fiber is added and adjusted to determine the best mix proportion.

Abstract: Two models of hollow core slabs were tested: reinforced concrete and steel fiber concrete. When designing slab models, the proportions of full-sized structures were preserved for the further possibility of correct data comparison. As a result of testing models of hollow core slabs, it was found that the bearing capacity of a slab with combined reinforcement is 24% higher than that of reinforced concrete, the deflection is 36% less, and the crack resistance is 18% higher. The use of steel fiber made it possible to avoid the brittle fracture of a steel fiber reinforced concrete slab, which was observed in the model of a conventional reinforced concrete slab.

Abstract: Fiber-reinforced concretes are varieties of composite materials. Such materials are commonly used nowadays. Concrete is fiber-reinforced using various fibrous materials, or fibers, which are evenly distributed over the volume of the concrete matrix and simultaneously provide its 3D reinforcement. Fiber-reinforced concrete has better stress-related strength characteristics than ordinary concrete. Since building structures must meet both the strength, rigidity and stability requirements, and the fire safety requirements, then for the extensive use of fiber-reinforced concrete structures, not only the external load design, but also temperature effect design should be conducted in the design phase. The strength and strain characteristics of fiber concrete exposed to high temperatures must be known for this purpose. In view of this, three series of prisms were manufactured and tested: the first series contained no fiber at all (control prisms), the second series contained basalt fiber, and the third series contained steel fiber. The test results showed that adding fibers improves the mechanical characteristics of fiber-reinforced concrete samples under specified conditions.

Abstract: It is studied that effects of different amounts of steel fiber and glass fiber on the compressive strength, flexural strength, and compression ratio and bond strength of styrene-acrylic emulsion modified mortar under different ages. The results show that the compressive strength, flexural strength and bond strength of mortar increase with the increase of steel fiber content, and the toughness improvement effect is obvious. With the increase of glass fiber content, mortar compressive strength, flexural strength and bond strength first increases and then decreases. Combined with SEM analysis and theoretical calculation to analyze the mechanical strength mechanism of fiber reinforced polymer mortar.

Abstract: This research is a comparative study, the use of carbon fiber and steel fiber for Self-Compacting Concrete (SCC). In previous studies, it was proven that the addition of steel fibers can increase the compressive and tensile strength of SCC. While carbon fiber is one of the most widely used materials for structural reinforcement in recent years. Therefore it is necessary to do a comparative study of the use of carbon fiber if applied to SCC. The percentage increase in carbon fiber and steel is 0.5%, 1%, and 1.5%. Then do the testing of: slump test, compressive strength, tensile strength and flexural strength. The results showed the optimal percentage of steel fiber addition of 1.5%, can increase the compressive strength of SCC by 11%. However carbon fiber and steel do not increase the tensile strength of SCC, and tend to reduce flexural strength. Other results show that carbon fiber is not suitable for use in SCC.

Abstract: The number of researches on steel fiber reinforced concrete (SFRC) fire resistance is insignificant. For the calculation of building structures for fire resistance, it is necessary to use the thermophysical characteristics of concrete: thermal conductivity, heat capacity and thermal diffusivity. The physicomechanical characteristics of SFRC depend on the volumetric content of the fiber in it. This paper presents the results of studies of thermophysical properties of SFRC. The studied SFRC had a high-strength self-compacting cement-sand matrix and a different percentage of fiber content (from 0 to 6%). The experiments were carried out for SFRC with steel wavy fiber 15 mm long and 0.3 mm in diameter. As a result of experimental studies, it was discovered that with an increase in the volumetric content of the fiber, a decrease in the values of heat flow, thermal conductivity and thermal diffusivity coefficients, specific heat capacity is observed and the thermal resistance of SFRC increases.

Abstract: Research on the preservation and restoration of masonry arches is of interest for the scientific and civil engineering communities, and the construction industry. Among the open investigation topics in the field, the study of new materials for strengthening masonry arches has gained attention from researchers. In this context, this paper presents the experimental results from destructive tests carried out on a masonry arch strengthened with steel fiber reinforced mortar (SFRM). The tested masonry arch was made of solid clay bricks disposed in a single layer and was strengthened with a single layer of steel FRM bonded at the arch intrados. In order to replicate the possible condition of an existing arch in which acting loads exceeded the member strength, the arch was preloaded before strengthening. The performance of the strengthened arch is discussed in terms of witnessed failure mode, ductility and increase in the load carrying capacity with respect to unstrengthened condition.

Abstract: Before and after the completion of a project we often encounter unforeseen events that affect the sustainability of the project. We understand that engineers and practitioners need to look for the best average or process in terms of quality and cost, to ensure project maintenance. Among the possible methods; we can quote the concrete reinforced by the metallic fibers between the pavement and asphalt concrete pavement, the latter will ensure the continuity between two materials (flexible-rigid). This work consists of studying the formulation of a metal fiber concrete based on local materials (cement, gravel and sand) and studying the effect of fibers. The results of this study highlighted the improvement of both the mechanical properties of concrete and the problem of cracking between the pavement and pavement concrete joints.