PSI - Issue 70

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ScienceDirect

Procedia Structural Integrity 70 (2025) 215–222

Structural Integrity and Interactions of Materials in Civil Engineering Structures (SIIMCES-2025) Flexural behaviour of ternary blended ambient cured geopolymer concrete slabs Nithin A V a,b,* , Deepa Raj S a , Mini Soman a a Department of Civil Engineering, College of Engineering Trivandrum, Affiliated to APJ Abdul Kalam Technological University (APJAKTU) Thiruvananthapuram, Kerala, India b Department of Civil Engineering, Vidya Academy of Science and Technology, Technical Campus, Kilimanoor, Kerala, India Abstract The study focuses on the development of a novel ternary blended ambient-cured geopolymer concrete (TBGC) using hydrous clay (HC) as a source material and copper slag (CS) as a fine aggregate material. Three different TBGC mix proportions were analyzed, varying the proportions of source materials like fly ash (FA), HC, and ground granulated blast furnace slag (GGBS). The sodium silicate to sodium hydroxide ratio (SS/SH), alkali solution to precursor ratio (AL/B), and molarity of sodium hydroxide (M) were considered as 2.5, 0.4, and 12, respectively for all mixes. The precursor proportion of FA, HC and GGBS used in the slabs were 60:0:40; 30:30:40 and 30:30:40, respectively. The incorporation of M-sand with 40% CS; 30% HC,30% FA and 40% GGBFS as precursors enhanced the mechanical properties of TBGC without compromising workability. This study also aims to evaluate the structural performance of simply supported two-way reinforced concrete slabs of 1.5 ×1.0 m effective span under a 16-point loading system. All slabs were casted with a uniform thickness of 60 mm and a span-to-depth ratio of 25. Experimental results showed that the TBGC-based slabs demonstrated improved load-bearing capacity, higher first-crack and yield loads, greater energy absorption, and significantly reduced deflection under 16-point flexural loading. The replacement of 40% M-sand with CS improved stress distribution and interfacial bonding, enabling the less reactive HC content to be increased to 30% without compromising the flexural strength of TBGC slabs. The TBGC slab incorporating CS and HC demonstrated a 44.68% higher load-carrying capacity compared to the control slab specimen.

© 2025 The Authors. Published by ELSEVIER B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under the responsibility of International Conference on Structural Integrity Organizers

K eywords: Ternary geopolymer concrete; 16-point concentrated load; Experimental; Flexural performance; Two-way supported slabs.

* Corresponding author. Tel.: +91-7736386183. E-mail address: tve19jan026@cet.ac.in, nithinav2312@gmail.com

2452-3216 © 2025 The Authors. Published by ELSEVIER B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under the responsibility of International Conference on Structural Integrity Organizers 10.1016/j.prostr.2025.07.046