5. Conclusions and recommendations

The state of the research on TDA concrete warrants further studies on analytical, experimental, and practical areas. On material properties, the environmental impacts on durability of rubber and long-term properties of TDA concrete is an area of interest for future research. Further, investigating the micromechanical characteristics of the bond between rubber particles and the cement paste is essential to understand the mechanical properties of TDA concrete, including toughness and tensile strength, better. Constitutive modeling and numerical simulation of the behavior of rubberized concrete are other areas of interest that can benefit from recent advancements in computational engineering and mechanics.

Application of TDA concrete requires development of design guidelines and specifications. Defining strength reduction factors is an area that requires further development. Current research studies are scattered in respect to parametric modeling and can benefit from additional experimental results. Further, these parametric analyses are essential for optimization of TDA concrete mix design to obtain proper rubber content for specific objectives. In addition, practical issues in mixing and placing concrete require development of proper specifications for handling TDA materials in concrete.

Mechanical properties of TDA concrete have shown to be desirable for many applications, such as traffic and sound barriers. Toughness and ductility of TDA concrete can be also effective in concrete elements subject to dynamic loads caused by earthquake and wind. Large-scale experimental studies are required for investigating these applications.

There has been limited studies on alternative TDA concrete products with application of fiber reinforcement, lightweight aggregate, fiber-reinforced polymers, admixtures, and supplementary cementitious materials. Enhancing the properties of TDA concrete using these methods require further research.
