Author Identifier (ORCID)
Abstract
High-strength concrete (HSC) with low water-to-cement ratios undergoes self-desiccation, resulting in incomplete hydration, capillary porosity, and autogenous shrinkage that can compromise long-term performance. Polyethylene glycol (PEG) functions as an internal curing agent by releasing stored water as internal relative humidity decreases, thereby sustaining hydration within the cement matrix. However, the combined influence of PEG grade, dosage, and fibre type on the constitutive response, fracture behaviour, and environmental performance of M65 HSC remains insufficiently understood. This study investigated twelve concrete mixes incorporating three curing regimes viz. Conventional curing, spray curing, and PEG-based internal curing (IC) using PEG 4000 (1.5%) and PEG 6000 (1.0%) by weight of cement, together with unreinforced, steel fibre, and coir fibre reinforcement at a volume fraction of 0.5%. Compressive and splitting tensile strengths at 28 and 56 days (n = 3) were evaluated using one-way ANOVA with Bonferroni correction. Experimental stress–strain behaviour was assessed against the Hognestad and Popovics constitutive models, while microstructural characteristics were examined using scanning electron microscopy (SEM). Environmental impacts were quantified through a cradle-to-gate life cycle assessment following ISO 14040/14044 using the ReCiPe 2016 Endpoint (H) method. Among all mixtures, the PEG 6000–steel fibre mix (P6S) achieved the highest 56-day compressive and splitting tensile strengths of 89.0 MPa and 5.50 MPa, representing increases of 20.3% and 48.6%, respectively, compared with conventionally cured concrete (p < 0.01). The Popovics model provided the best prediction for P4S (R2 = 0.978), whereas both constitutive models showed poor applicability to internally cured mixes without fibre reinforcement, indicating the need for model refinement for PEG-cured HSC. SEM observations revealed a denser and more interconnected C–S–H network in PEG 6000 mixes, while spray-cured specimens exhibited larger voids and ettringite-rich regions. From an environmental perspective, PEG 4000 internal curing reduced the human health endpoint impact by 29.0% relative to conventional curing (0.0510 versus 0.0718 DALY/m3), and the PEG 4000–coir fibre mix (P4C) achieved the lowest strength-normalised impact (0.594 × 10−3 DALY/MPa/m3), representing a 38.8% reduction compared with the conventional benchmark. The findings demonstrate that steel fibres maximise mechanical performance, whereas coir fibres offer superior environmental efficiency, highlighting the importance of selecting fibre reinforcement according to project-specific performance and sustainability objectives.
Keywords
fiber-reinforced internally cured concrete, life cycle assessment, PEG 4000 and 6000, steel and coir fiber, stress-strain analyses
Document Type
Journal Article
Date of Publication
8-1-2026
Article Number
101275
E-ISSN
26667908
Volume
33
Publication Title
Cleaner Engineering and Technology
Publisher
Elsevier
School
School of Engineering
RAS ID
101739
Creative Commons License
This work is licensed under a Creative Commons Attribution-Noncommercial-No Derivative Works 4.0 License.
Recommended Citation
Kiran V, K., Sathyan, D., & Shukla, S. K. (2026). Constitutive behaviour, failure mechanisms, and life cycle assessment of internally cured fiber-reinforced high-strength concrete. Cleaner Engineering and Technology, 33, 101275. https://doi.org/10.1016/j.clet.2026.101275