• MATERIALS

    A study on deflections of GFRP reinforced concrete beams.

    Machines. Technologies. Materials., Vol. 17 (2023), Issue 8, pg(s) 329-333

    Steel reinforcing bars have not performed well in applications where members were subject to corrosive environments. Alkaline concrete protection can provide relatively good protection of the steel reinforcement, but when these are exposed to an aggressive environment or the protection breaks down, the reinforcement starts the corrosive process and it leads to rupture and fragmentation of the protective layer of concrete.
    These reasons lead to high maintenance costs, repairing or even replacing them. This problem prompted a lot of researchers to seek alternative materials with characteristics better than steel to be used in construction. GFRP bars, which are fibers with high resistance immersed in a polymer resin matrix, with a high tensile resistance and also resistant to corrosion, emerged in the 1990s as an alternative to replace steel rods. The use of GFRP is increasingly accepted by the countries, which are trying to create or adopt special codes for their use in building structures.
    This paper will take a quick look over GFRP materials and their mechanical properties, but also will aim to provide some ideas on the study of concrete members reinforced with GFRP bars and their design based on SLS method as it rapresents the most problematic one, focusing on deflections of GFRP reinforced beams.

  • MATERIALS

    MECHANICAL CHARACTERIZATION OF RECYCLED POLYPROPYLENE AND COPOLYMER MACRO FIBERS IN CONCRETE

    Machines. Technologies. Materials., Vol. 11 (2017), Issue 3, pg(s) 141-143

    Waste materials have been an increasing problem every year. Disposal of waste materials has presented very serious problems to the human community in the world. Currently, some research has been studied to the recycle of different wastes in concrete. Recent study is focusing on the usage of a unique blend of recycled polypropylene and copolymer macro fibers (RPCMF) designed specifically for concrete mixture. The different weight of RPCMF is mixed in concrete to in order to investigate the effect on mechanical properties. By adding RPCMF obtained a satisfactory improvement on cracking control, compressive strength, flexural strength and also tensile strength, Moreover, compressive, flexural and tensile strength was positively affected by the addition of RPCMF for some mixtures. More percentage of weight fractions added gives high result in tensile strength. However, the workability of the concrete reinforced with RPCMF was negatively affected.