Abstract:
The concrete industry is one of the main consumers of natural resources, many efforts were
made to replace natural resources with non-depleted one without significant influence on
concrete properties. In numerous research studies, different waste materials were incorporated,
depending on the properties needed from composites. One of today’s major environmental
problems is non-decaying waste tires: left in the environment, they present a great danger for the
earth and leaving creatures. This study utilizes the waste tire crumb rubbers in concrete as a
partial replacement of the natural fine aggregate in C-25 concrete grade to produce a green
concrete and to investigate its structural behavior with a reinforcement bar using FEM.
An experimental study was carried out on the basic mechanical properties of concrete to
investigate the effect of waste tire rubber on the workability, compressive, tensile, flexural
strength and stress-strain relationship. FE and numerical studies were also carried out to
determine the impact of resistance and deformation of rubberized concrete. A modified concrete
was prepared by replacing sand in concrete with rubber aggregate by varying the replacement
proportion from 4% to 16% with an increment of 4% by volume. Among different pretreatment
used to increase the bond between the rubber particles and cement matrix, washing the rubber
with 5% diluted H2O2 was used to enhance the adhesive properties. After having the mechanical
property from the experiments, an effective finite element model was developed in ANSYS
workbench to analyze the structural behavior of reinforced CRC. The stress-strain diagram from
the experiment was described by command and used as input data in ANSYS simulation.
From the experiment, it was found that the optimal rubber improves the strain capacity and its
stress-strain curve shows more nonlinear behavior than NC. From all percentages, CRC8 shows
best relative performance it improves impact resistance, energy absorption and ductility of
concrete by decreasing the weight of the structure. CRC8 gives an average compressive strength
of 28MPa which is greater than the minimum requirement. At failure, CRC exhibited more
ductility with large ultimate deflection and more uniform crack distribution. The bond behavior
of CRC8 with the deformed bar is only slightly lower than NC. ANSYS output result shows that
the structural behavior like maximum stress is comparable except the reduction in compressive
strength. The results of FEA positively verified that rubberized concrete could absorb more
impact energy before failure. At ultimate load, elements are failing more in NC than CRC8.