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Carbon Fiber Reinforced polymer (CFRP) bars are weak in yielding property which results in sudden failure of structure at failure load. Inclusion of non-pretensioned steel reinforcement in the tension side of CFRP based prestressed concrete beam will balance the yielding requirements of member and it will show the definite crack failure pattern before failure. Experimental investigation has been carried out to study the deflection behavior of partially prestressed beam. Experimental works includes four beam specimens stressed by varying degree of prestressing. The Partial Prestressing Ratio (PPR) of specimen is considered for experimental works in the range of 0.6 to 0.8. A new deflection model is recommended in the present study considering the strain contribution of CFRP bar and steel reinforcement for the fully bonded member. New deflection model converges to experimental results with the error of less than 5% . [ABSTRACT FROM AUTHOR]

An experimental investigation was conducted to study the influence of deformability behavior in carbon-fiber-reinforced polymer (CFRP) prestressed concrete beams. The moment curvature of CFRP prestressed beams does not follow the linear stress-strain curve, showing that there is some amount of energy absorbed, which influences the serviceability behavior of members. Four beam specimens were cast, stressed at deformability index values varying from 1.35 to 2.88, and tested. Numerical analysis was conducted using the experimental results. It was concluded that the deformability of beam influences the serviceability behavior of the beam and proposed new deflection model. The proposed model is an efficient method for calculating deflection compared with the ACI 440.4R-04 method. A design chart is suggested for calculating effective moment of inertia and effective neutral axis distance. The influence of the deformability index in crack width, crack spacing, number of crack pattern, and crack stabilization load are also described. [ABSTRACT FROM AUTHOR]

Fiber-reinforced polymer (FRP) composites are preferred as prestressing tendons in concrete structures due to its high-strength, lightweight and non-corrosive property. FRP based prestressed concrete member exhibits different crack behavior than steel based prestressed concrete member due to its less stiffness and non-ductile property. An experimental investigation was carried out to study the cracking behaviour of concrete member using Carbon fiber reinforced polymer (CFRP) bars as prestressing material. Experimental works includes four numbers of prestressed concrete specimens by varying degree of prestressing of 35 to 70%. The characteristics of crack spacing, crack propagation and crack widths of member were presented. Experimental results were compared with various researchers' recommendation and proposed a new crack width model by modifying the Frosch crack width model. [ABSTRACT FROM AUTHOR]

Numerical model analysis was carried out to study the deflection behaviour of FRP-based prestressed concrete (PSC) beam, because it does not resemble the existing deflection model of steel tendon-based PSC beam due to its non-ductile property. Deflection model by various researchers for the FRP-based PSC beams are underestimating as compared to experimental results which lead to unsafe design. There were 51 numbers of experimental results which were collected from various research articles for the numerical model analysis. Lagrange dual function convex optimisation used to predict the effective moment of inertia and shift of neutral axis distance. It reveals that the deflection of FRP tendon beam depends on deformability of material, degree of prestressing and bond strength. Design chart suggested for calculation of effective moment of inertia and effective neutral axis distance with respect to deformability index. The maximum deflection error by the proposed method is less than 5% as compared to experimental results. [ABSTRACT FROM PUBLISHER]

The article discusses the study that determines the strength characteristics of plain cement concrete and glass fiber by mixing exposy resin. Discussion on the method of the study that aims to overcome the disadvantages of plain cement concrete by adding fibers to convert it into a ductile material is provided. The findings of the study which recommend the advantage of mixing fibre reinforced polymers into concrete cement are offered.

Geopolymer concrete can be considered as a Green building technology that serves as an alternative for cement and river sand by using Alkaline Activator Solutions (AAS) and Copper Slag (CS). To attain High Strength Geopolymer Concrete (HSGC) trial tests were carried out by creating eleven different mix proportions with replacement of binder material fly ash by Ground Granulated Blast Furnace Slag (GGBS) from 0% to 100% by weight at increments of 10%. Alkaline activator solutions (14 molar Sodium Hydroxide and Sodium Silicate) were used in this study for polymerization. In each different mix proportion, specimens were cast and heat curing was done by maintaining 70 degree Celsius for 24 hours. The specimens were tested for strength parameters like compressive strength, split tensile strength and flexural strength. From the test results, combination of 60% GGBS and 40% fly ash produced high compressive strength of 71 N/mm2. Further, an attempt was made with the same proportion of binder material and by replacement of river sand with Copper slag from 0% to 100% by weight at increments of 10%, eleven different mix proportions were made. It is understood from the strength test results, substitution of 50% copper slag by sand yielded a high compressive strength of 77 N/mm2. Thus, the above mix combination resulted in high strength geopolymer concrete. [ABSTRACT FROM AUTHOR]