Experimental Researches on the Behavior of Polypropylene Pipes at the Physical-mechanical Testing

Lately, PP-R pipes have become increasingly popular in terms of drinking water installations and heating. Comparated to the classic pipes from copper or steel, pipes from propylene are much easier to use, they have obvious qualities and they are marketed at a much lower price. The study aims a comparative analysis of the physical-mechanical properties of the four most common types of pipes from propylene, which are currently found in commerce : simple without insertion(PP-R), with insert of composite fiber (PP-R-CF), with insert of basalt fiber (PP-R-BF) and with insert of aluminium (PP-R-AIF). Experimental research showed that from the point of view of thermal expansion, the best behavior is from the pipes from propylene without any insert and the value of the thermal expansion coefficient for the reinforcement pipe with basaltic fiber is very small. After these attempts at tensile, it resulted that all four samples which were analyzed from the point of view of the tensile strength, don�t exceed the limit that was given by the manufacturer (10-30 MPa), the values obtained being: for pipe from polypropylene of 17 MPa, for pipe from polypropylene with insert of aluminium of 18 MPa, for the test tube from pipe of polypropylene with insert of basalt fiber of 29 MPa and for the test tube from pipe of polypropylene with insert of composite fiber of 30 MPa. Therefore, from the point of view of the behavior at tensile and bending, the best behavior is from the pipes from polypropylene with insert of basalt fiber and pipes from polypropylene with insert of composite fiber.

Strength and Deformability of Fiber Reinforced Cement Paste on the Basis of Basalt Fiber

The research object of the paper is cement paste with the particulate reinforcement of basalt fiber. Regardless of fibers’ length at the same fiber cement mix workability and cement consumption equality compressive solidity of the specimens is reduced with increasing fiber content. This is due to the necessity to increase the water-cement ratio to obtain a given workability. The flexural stability of the specimens with increasing fiber content increments in the same conditions. There is an optimum value of the fibers’ dosage. That is why stability has a maximum when crooking. The basaltic fiber particulate reinforcement usage can abruptly increase the cement paste level limiting extensibility, which is extremely important in terms of crack resistance.

Experimental Study on Flexural of RC Beams Strengthened with Basaltic Fiber Sheets

The bending performance test on one ordinary reinforced concrete beam and six RC beams strengthened with basalt fiber sheets(BFRP) is carried out, and the bending performance of the RC beams strengthened with BFRP is analyzed. The experimental results show that BFRP improves the bending performance of the beam. Pasting one layer,two layers or three layers of BFRP, The ultimate strength RC beams were increased by 29%, 56% and 78%. Basalt fiber sheets and concrete beams can work better together and play an effective role in reinforcement.