Steel reinforcement rubber concrete

Concrete workers are unskilled workers engaged at the building sites. During construction they work largely out of doors where they pour the pre-mixed concrete into moulds containing steel reinforcements. The concrete is then vibrated manually. These workers often walk on newly poured concrete foundations while wearing rubber boots (Fig. 3). They have contact with wet cement, primarily on the hands, forearms... 

Fiber-reinforced plastics are the most successful composite materials. In spite of the poor load-bearing ability of polymeric materials, excellent mechanical properties are achieved by using fiber architectures of glass and carbon hbers in a manner similar to the reinforcement of concrete with steel rods and frames. For example, toughened polymeric materials with dispersed rubber particles in a polymer matrix exhibit high fracture energy. In composite materials, introduction of secondary materials into the matrix can improve the mechanical properties considerably. 

A total of four types of recycled fiber plus two types of virgin fiber were used as the reinforcement in concrete. Three recycled fibers were obtained from disposed tires and one from carpet waste. The tire fibers included two types of tire fabrics composed of polymeric tire cords, tire-rubber strips which were the main component of tires, and tire steel fibers which were the radial steel reinforcement of tires. The fibers from carpet waste contained backing fibers (nsually polypropylene), latex adhesive particles, and a small amount of face fibers. In addition, hooked end steel fibers and FiberMesh polypropylene fibers were also used as virgin fibers for comparison. Recycled fiber volume fractions in each composite were fixed at 2% except that the tire steel fiber and the virgin fibers (steel fiber and FiberMesh) were used at a 1 vol%. 

As we have mentioned in the introduction, rubber parts typically experience large displacements and strains during their deformation history and, therefore, linearization based on the theory infinitesimal strains and small displacements that is traditionally employed for steel, reinforced concrete, and so on will produce inaccurate results. In order to retain the accuracy and realistic description of the deformation process in mbber, a fully nonlinear description of the deformation process should be considered. In the following discussion, we will obtain discretized finite element equations and outline their solution methods. 

Most metals, concrete, and other construction materials are corroded by hydrobromic acid. Suitable materials of construction include some fiber glass-reinforced plastics, some chemically resistant rubbers, PVC, Teflon, polypropylene, and ceramic-, rubber-, and glass-lined steel. Metals that are used include Hastelloy B, Hastelloy C, tantalum, and titanium. The Hastelloys can only be used at ambient temperatures. Liquid hydrogen bromide under pressure in glass at or above room temperature can attack the glass resulting in unexpected shattering. 

Process piping-carbon steel, alloy, cast iron, lead, lined, aluminum, copper, ceramic, plastic, rubber, reinforced concrete Pipe hangers, fittings, valves Insulation-piping, equipment... 

Brick-and-rubber-or brick-and-polyester-lined steel Rubber- or lead-lined steel Polyester, fiberglass-reinforced Aluminum Copper Concrete... 

The recycled rubber crumb obtained by the BTRC UHP process can be vulcanised again, on its own or used in new compounds, providing that there is compensation for the sulfur present, in the same way as virgin NR or SBR. The BTRC process also removes the clean, high-value steel wire (steel needles used as concrete reinforcement) and the textile (fluff used as rubber reinforcement) (Figure 6.5). 

K.T. Iyengar, TS. Nagaraj and B.K. Rao, Superplasticized natural rubber latex modified steel fibre reinforced concretes , Paper 3.3 in R.N. Swamy, R.E. Wagstaffe and D.R. Oakley (eds) Developments in Fibre Reinforced Cement and Concrete, Proc. RILEM Symp., Sheffield, RILEM Technical Committee 49-ETR, 1986. 

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