Experimental Study on Mechanical Properties of Basalt Fibre Reinforced Concrete
Concrete is very strong in compression but very weak in tension. However it is reported that tensile and bending strength of concrete is 10 to 15% of the compressive strength respectively. The addition of different types of fibres in concrete have significantly improves its compressive as well as tensile strength. Among the new advancement in field of FRC is the basalt fibre reinforced concrete. In the present study basalt chopped fibres were used in the concrete mixes and compressive and flexural strength of the specimens were tested. A total of 5 mixes were prepared by varying the percentages of basalt fibres on M 25 grade of concrete mix. Based on the laboratory results the compressive and flexural strength was reported to increase up to 46% and 74%. However the workability of fresh concrete mixes is not much affected by the addition of fibre content. The flexural strength of concrete is improved which shows the wide application of basalt fibres in concrete mixes for construction in various fields i.erailway, bridges, runway and tunnels.
Flexural experimental study on continuous reinforced concrete beams strengthened with basalt fiber reinforced polymer/plastic
This paper discusses a new fibrous composite known as continuous basalt fiber reinforced polymer/plastic (BFRP). Compared with other fiber reinforced polymer/plastic, BFRP has many advantages, such as ductility, high thermal resistance, corrosion resistance and economic cost. To test mechanical properties and failure modes of flexural members strengthened with BFRP, flexural experiment is conducted on four two-span T-section continuous beams strengthened with BFRP and one un-strengthened comparative beam. The experimental result shows that the strengthened beams perform remarkably in terms of yield strength, ultimate strength and ductility. BFRP has good prospects in retrofitting and strengthening of concrete structures which require good ductility and corrosion resistance.
Experimental study on bond behavior between high-strength grout and deformed steel bars
Abstract Engineers use high-strength grout to connect precast concrete members for its low shrinkage and good fluidity. This paper designed 87 central pull-out specimens using the control variable method to investigate the influence of factors on the rebar-grout bond property such as compressive strength, steel grade, bar diameter, transverse stirrups, and bond length. The test result showed that improving grout compressive strength (85.8 MPa–122.7 MPa) cannot improve the bond strength, which was different from the previous conclusions of concrete pull-out tests. Simplified formulas were presented for calculating the characteristic values of bond strength, residual strength, peak slip, and relative slip of load-holding platform based on parameter analysis. Then, a constitutive model was proposed to predict the full-range bond stress-slip curve of high-strength grout and steel bar specimens from bearing to failure. Finally, FEA models were established to evaluate the applicability and accuracy of the constitutive model.