Theme / Problem Statement: Mix design framework for hybrid fiber reinforced concrete ensuring high seismic performance.
Research Objectives:
- Which fibre is the best suited for mix design of HPFRC? In other words, proposing a type of fibre having strength in the order of metallic but specific gravity in the order of non-metallic is one of the objectives of this proposal.
- Achieving HPFRC with using coarse aggregates is another objective to maintain economy for large scale applications.
- Developing a mix design framework for HPFRC that a) takes into account not only the compressive strength but also the tensile strength and b) uses a capacity-based principle so as to enforce an intended failure mode during compression testing of concrete cubes leading to reduced dispersion in strength.
- Developing a flow table test for the optimum dosage of superplasticizer taking into account the presence of fine aggregates.
- Proposing uniaxial stress-strain relation for the HPFRC.
- Assessment of the performance of HPFRC through flexural testing of beams.
Methodology:
- Selection of Fibres
- Achieving HPFRC with using Coarse Aggregates (CA)
- Mix Design Framework–using a capacity-based principle and taking into account the tensile strength:
A. Testing of Coarse Aggregates
B. Target Compressive Strength of Concrete -vs- Target Mortar Strength:
C. Trial Concrete Mix-Design with a Pointer on Target Mortar Strength:
D. Final / Trial Concrete Mix with a Pointer on Target Concrete Strength:
E. Strength of ITZ
F. End Product–Reduction in Dispersion - Superplasticizer dosage considering presence of fine aggregates
A. Without considering the presence of fine aggregates
B. Considering presence of fine aggregates - Uniaxial stress-strain relation
- Assessment of the performance of HPFRC
Expected Outcome and Deliverables of the Project:
- The best suited fibre for mix design of HPFRC, i.e., a type of fibre having strength in the order of metallic but specific gravity in the order of non-metallic.
- Mix design procedure for HPFRC with following contributions: i) It does not eliminate coarse aggregates and hence, is economical, ii) It takes into account the tensile strength in addition to the target compressive strength, and iii) the reduced dispersion in compressive strength on account of a capacity-based approach ensures the quality of concrete.
- A new test procedure for estimating the pure shear strength of concrete and mortar.
- Uniaxial stress-strain plot of HPFRC in both compression and tension.
- Stress-block parameters for design with HPFRC.
- A flow table test for assessing the optimum dosage of superplasticizer.
Publication out of this Project:
Journal Publications
- Mushtaq, S. M., Rajput, T., Basu, D. (2022). “Cement-superplasticizer compatibility and flow properties of binder paste and mortar using marsh cone and flow table method”, The Indian Concrete Journal, Vol. 96, No. 9, pp. 20-33.
PDF - Sharma, S., & Basu, D. (2023). Influence of supplementary cementitious materials on transport properties of concrete and interfacial transition zone. Current Science (00113891), 124(11).
PDF - Basu, D., Mushtaq, S.M., Sharma, S., Tripathi, S. Enhancing Quality Control in the Mix Design of High-Strength Concrete Using a Capacity-Based Approach. Int J Concr Struct Mater 18, 78 (2024). https://doi.org/10.1186/s40069-024-00722-8
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Contributed Papers/Abstracts in Published Conference Proceedings
- Sharma, S., Tripathi S., and Basu, D. (2024). Empirical Relationships for Mohr-Coulomb Parameters in Concrete & Mortar: Application in Mix Design. In 18th World Conference on Earthquake Engineering (WCEE 2024).
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Article
- Exploring Ductility in Singly Reinforced Fiber Reinforced Beams: Insights from Three-Point Bending Tests. Abstract article in Student Research Spotlight (May, 2024), International Society for Concrete Pavements (ISCP).
