Experimental and numerical assessment of an optimized geopolymer repair mortar for the filling core-drilled holes in conventional concrete
Journal of Sustainable Cement-Based Materials, 2026 (SCI-Expanded, Scopus)
- Yayın Türü: Makale / Tam Makale
- Basım Tarihi: 2026
- Doi Numarası: 10.1080/21650373.2026.2697459
- Dergi Adı: Journal of Sustainable Cement-Based Materials
- Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Applied Science & Technology Source, Chemical Abstracts Core, Engineering Source (EBSCO)
- Anahtar Kelimeler: core-drilled hole repair, elevated temperature performance, Geopolymer repair mortar, microstructural characterization, modelling of repair mortar–substrate interaction
- İnönü Üniversitesi Adresli: Evet
Özet
During in-situ strength assessment, using unsuitable repair mortars to fill core holes created by core sampling may interrupt stress transfer and reduce structural performance. This study comprehensively evaluates the performance of an optimized geopolymer repair mortar (GRP) and a commercial repair mortar (CRP) used to fill core-drilled holes in conventional concrete (CC) specimens. First, GRP mixtures were optimized based on silica fume (SF) substitution and NaOH concentration. The optimum mixture, containing 15% SF and activated with 10 M NaOH achieved a 28-day compressive strength of 36.5 MPa, which was competitive with CRP (39.4 MPa). After filling core holes in CC specimens with GRP and CRP, the performance of these specimens was compared with non-cored (reference) CC specimens. The specimens were evaluated under ambient conditions and after exposure to elevated temperatures using compressive strength, UPV, water absorption, microstructural analyses and finite element modeling (FEM). The results showed that, although CRP achieved higher compressive strength under ambient conditions, GRP exhibited superior residual strength retention after elevated-temperature exposure, with strength losses of 19.2% and 54.0% at 400 °C and 800 °C, respectively, compared with 43.6% and 60.8% for CC and 49.2% and 75.7% for CRP. Moreover, the FEM predicted experimental compressive strength results with a mean absolute difference of approximately 6.73% and captured damage-progression, while microstructural analyses confirmed the competitive performance of GRP.