The study of concrete incorporating different waste fibres has started to increase rapidly due to economic reasons and positive environmental effects. In the study reported here, waste steel wires from steel reinforcement and used formworks were blended with structural lightweight concrete, with the aim of replacing commercial steel fibres of controlled quality with recycled fibres. Compression, tensile, flexural and impact tests were performed to assess the mechanical properties of 28 d old concrete specimens reinforced with mixed waste steel wires, mixed steel fibres as well as plain concrete. The percentages of fibres examined in the fibre reinforced concrete (FRC) specimens were 0 . 25%, 0 . 50% and 0 . 75% (volume fraction of the concrete). With varying fibre contents, similar trends were observed in all the types of FRCs studied. It was thus concluded that waste steel wires could be used as a suitable alternative to industrial steel fibres for structural lightweight concrete applications. Notation ddiameter of concrete cylinder I 5 , I 10 , I 20 toughness indices l length of concrete cylinder P maximum applied load indicated by the testing machine R 5,10 , R 10,20 residual strength factors T splitting tensile strength V f fibre content (% volume fraction of concrete)

This investigation is focused on bending experiment of some prismatic perlite lightweight concrete. In these samples, textile waste fibers are confined with textile mesh glass fiber and embedded in the central part of cubic lightweight concrete specimens. Bending experiments revealed that lightweight concrete panels with a core of textile waste fiber have less density than water and high energy absorption and ductility. Furthermore, these composite panels by having appropriate thermal insulation characteristics could be used for partitioning in the buildings.

Nowadays, the use of different waste fibers in concrete has started to increase rapidly due to some reasons such as economic savings and positive effects on the environment. In this study, waste steel wires taken from reinforcement and formwork which were previously utilized in construction projects, were employed in structural lightweight concrete (SLWC). The objective was to investigate the possibility of using this type of fiber as reinforcement in the SLWC. Compressive, tensile, flexural and impact tests were performed for investigating the mechanical properties of 28-day reinforced lightweight concrete specimens with the waste wires. The percentage of wire in the fiber reinforced concrete (FRC) was 0.25%, 0.5% and 0.75% in the volume fraction of the concrete. According to the results, by using waste wires, flexural, tensile and impact characteristics of SLWC were effectively improved. Moreover, it was concluded that waste steel wires could be used as a suitable micro reinforcement in the SLWC.

Using lightweight panels in buildings has significant role on decreasing the dead loads as well as the earthquake induced loads. From economical point of view, using lower amounts of materials due to decreasing the dimensions of structural sections as well as less transportation expenses directly leads to reducing the construction costs. On the other hand, use of lightweight panels with thermal isolation property, decreases the performance cost, effectively. This study focuses on some samples of perlite lightweight concrete. In these samples, waste textile fibers confined with textile meshes embedded in central part of each sample have been used. The bending tests of the samples indicated that light perlite concrete panels including confined waste fibers in the central core lighter than water having high ductility could be fabricated. These panels have energy absorption as well as high ductility characteristic and could be used for partitioning with thermal and acoustic isolation.

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