CeSTaR 2: Reducing material demands and enhancing structural capacity of multi-spiral reinforced concrete columns - advanced simulation and experimental validation

Motivation

Based on the report by Andrea Larson, carbon dioxide (CO2) accounts for 77% of total greenhouse gas emission. And, the CO2 emission from steel and cement industries occupies 12% of the total CO2 emission. Moreover, according to the statistics of energy consumption in the first five months of 2019 published by Energy Bureau of Department of Economics of Taiwan it can be seen that the industrial sector consumes the largest amount of energy, accounting for 45% of the total energy consumption. The steel and cement industries accounts for 20% of the energy consumed by the industrial sector or for 9% of the total energy consumption. Therefore, savings in the use of steel and concrete are crucial in reducing the CO2 emission and energy consumption, promoting a greener environment for the place we live.
It has been shown by previous studies that the use of multispiral reinforcement (MSR) in square or rectangular columns can significantly save the amount of steel for transverse reinforcement and yet can still achieve a higher structural performance than conventional tie reinforcement. A higher structural performance means a further save in steel reinforcement and concrete can be made for a given structural performance. The test results have demonstrated that concrete confined by MSR as a new form of confined concrete material can reduce the use of concrete and steel as compared with conventional confined concrete and hence promote savings in energy and CO2 emission.
These trends should be supported by cooperation between computer modeling and experimental research. Experimental research could serve as a basis for identification of appropriate input data of computer models and adjustment/development of the material models, and also for verifying the results provided by computer models of structures or structural members. The software packages developed in the Czech Republic, namely ATENA software from Červenka Consulting and OOFEM by CTU will be extended for simulation of the investigated structural parts under complex loading conditions, which will increase their capabilities and open new potential markets and applications, in particular in locations and countries threatened by earthquakes.

Project objectives - Taiwanese side

  • Develop advanced multi-spiral columns to resist extreme loads such as large gravity and/or near-fault ground motions.
  • Conduct lateral cyclic testing of conventional and advanced multi-spiral columns to investigate the effects of design details on structural performance. Provide test results for FEM validations and optimizations.
  • Conduct shake table testing of conventional and advanced multi-spiral columns to validate dynamic structural performance of conventional and advanced multi-spiral columns. Test results can also be used for FEM development.
  • Conduct a series of experiments using monotonically increasing axial and eccentric compression on columns with MSR to supplement the FEM calculations with the data essential for their validation. From the tests and simulations, the behavior of confined concrete by MSR, particularly that in the overlapping region, will be further investigated.

Project objectives - Czech side

  • Software for the design and advanced FE modeling of reinforced concrete columns with the Advanced multi-spiral reinforcement (AMSR), which use both standard and prestressing type of reinforcement.
  • Develop formulae for the robust yet efficient design of columns with MSR incorporating the effect of multiple-confined zones. Develop the interaction diagram for the design of columns with MSR. These rules will be validated on Taiwanese experiments and incorporated in the Software.
  • Optimize transversal reinforcement from the perspective of cost, emissions, and structural response.
  • Explore the applicability of concrete Dual-mixing to precast elements. If the results are found promising, in the future the quantity of Portland cement can be significantly reduced making the precast elements even more energy and material efficient.