Reinforcement ratio

Trial Cross-Section. A trial cross-section is chosen that includes the concrete thickness, and the tension and compression steel percentages (in the horizontal and vertical directions for a two-way slab). The optimum distribution of horizontal and vertical steel is obtained when 45 degree yield lines are obtained in a yield-line analysis for ultimate resistance. The minimum steel percentage, either way and in tension or compression, is 0.15%. The optimum total positive or negative reinforcement ratio (p + py) has been found to be between 0.6% and 0.8%. A value in this range should be used for design. 

Table 3.4 shows some examples of the modulus and the strength reinforcement ratios for various reinforced thermoplastics and thermosets. The reinforcement ratio is the performance of the reinforced polymer divided by the performance of the neat polymer. 

Table 3.4 Examples of reinforcement ratios based on tensile strength and modulus...

For an industrial example (see Table 3.8), the reinforcement ratios obtained with a loading of nanosilicate as low as 2% are attractive. The reinforcement ratio is the ratio of the nanocomposite performance versus that of the neat polymer. 

Figure 6.8 plots the reinforcement ratios for short glass fibre reinforced polyamide (PA-GF) versus neat polyamide for six important characteristics calculated versus density and material cost. These characteristics are tensile strength, tensile and flexural modulus, impact strength, HDT A and B. 

Figure 6.8. Fibres examples of reinforcement ratios for short glass fibre reinforced PA 6...

The reinforcement ratio for performance/weight = (FMwpa gf)/FMwpa Except for HDT B (reinforcement ratio = 1), all the other reinforcement ratios are greater than one, up to nearly four for the modulus. 

As for glass fibres, reinforcement with continuous fibres leads to the highest performances. Compared to short glass fibres, short carbon fibres yield higher reinforcement ratios for the modulus and tensile strength but the impact strength decreases. 

Table 6.7 Examples of reinforcement ratios of CFRP and enhancement ratios versus GFRP...

The reinforcement ratios are moderate but there are other advantages ... 

The effect of the tensile steel reinforcement ratio, p, on the load-deflection and moment-curvature responses of PC beams is shown in Fig. 15. The moment was computed from the applied loads by statics while the corresponding curvature was calculated from the strain distributions. It is noticed that the load-deflection and moment-curvature responses are very similar in terms of shape. In the first stage of loading, a linear relationship existed between the moment (or load) and curvature (or deflection). This proportional limit stage ended with the formation of a major vertical flexural crack and the resulting change in slope and decrease in stiffness. 

Influence of Particle Size of Coarse Aggregates and Reinforcement Ratio of Fibrous RubCon Strength... 

Different factors, such as the reinforcement ratio, size, and form of fibers, and the particle size of a coarse aggregate, exert a great action on the mechanical properties of a continuously reinforced concrete. The influence of these parameters... 

A full two-factor experiment was carried out. The varied parameters were the reinforcement ratio /i and the particle size of coarse aggregate a response functions were the tensile, compressive, and bending strength of the polymer concrete samples measuring 4 x 4 x 16 cm and 4 x 4 x 40 cm. During the experiment, the reinforcement ratio and particle size were changed from 0% (without reinforcement) to 3% in 1% increments, and from 0 (without crushed stone) to 15-mm in 5-mm steps, respectively. 

The experiments have made it possible to propose a practical combination of reinforcing ratio and coarse aggregate quality assignment depending on the required... 

Experimental investigations were performed with fiber-reinforced RubCon samples measuring 4 x 4 x 16 cm. Various fiber materials were used steel, polypropylene, rough basalt, and glass. The reinforcement ratio for appropriate fiber materials was adopted according to publicized research [4,11]. The optimal volume of fiber content is 1.0%-1.5% for steel fibers and 1.0-5.0% for glass fibers. 

One of the major areas of RubCon application is in structures that operate in aggressive environments where crack resistance of the material is important. Our experiments have shown that steel fibers show the greatest opportunity to increase crack resistance and allow production of a material with high elastic-plastic properties. For this reason, we have undertaken research on the influence of fiber reinforcement ratio and aspect ratio on RubCon strength at compression, tension, and bend. 

FIGURE 2.36 Influence of reinforcement ratio p and aspect ratio L/d of the steel fibers on compression strength of fibrous RubCon. (Reprinted from Yu. Potapov, Yu. Borisov, D. Panfilov, O. Figovsky, and D. Beilin, Research of Polymer Concrete Based on Low Molecular Polybutadiene, Part VII Strength of Continuously Reinforced Polymer Concrete with Various Kinds of Fibers, J. Scientific Israel Technological Advantages 6, nos. 3-4 (2004) 71-74. With permission.)... 

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