Investigating the possibility of improving some of the mechanical characteristics of fiber-reinforced high-strength shotcrete in two wet and dry methods

Document Type : Original Research

Authors
M. ahmadian khameneh 1
H. afshin 2
M. Imami Tabrizi 3
Y. alilou Kisjini 4
G. Qudsi Sharif 5
1 Student of Sahand University of Technology
2 Associate Professor, Faculty of Civil Engineering, Sahand University of Technology, Tabriz
3 Assistant Professor, Faculty of Civil Engineering, Sahand University of Technology, Tabriz
4 Head of Civil Engineering and Architecture Working Group, Scientific, Research and Technology Organization of Alborz Province
5 Instructor of Faculty of Civil Engineering, Sahand University of Technology
10.22034/25.3.4
Abstract
Shotcrete, a pneumatically sprayed concrete mixture, has gained significant popularity in the construction industry due to its versatility and adaptability. However, the demand for high-strength shotcrete has intensified, driven by advancements in equipment and admixtures. Fiber-reinforced high-strength shotcrete (FRHSS) offers enhanced quality, adhesion, and construction speed, making it ideal for stabilizing excavations and slopes, strengthening masonry and concrete structures, and reinforcing underground structures. Additionally, the increased strength allows for reduced section dimensions, leading to more economical designs.



This research investigates the effects of aggregate gradation and admixtures, including micro silica, superplasticizer, accelerator, and micro recycled steel fibers (MRSFs), on the strength and performance of FRHSS. The study employs wet-mix and dry-mix shotcrete methods, examining the properties through laboratory and field experiments.



The results demonstrate that achieving high-strength shotcrete is more feasible with the wet-mix method. Fiber-reinforced wet-mix shotcrete attained a 28-day compressive strength of 987 kg/cm², representing an 80% and 77% increase in compressive strength and energy absorption, respectively, compared to conventional fiber-reinforced wet-mix shotcrete. Furthermore, fracture toughness tests revealed that MRSFs effectively prevent microcrack propagation and control deformations. FRHSS incorporating MRSFs exhibited a 28% and 97% increase in compressive strength and energy absorption, respectively, compared to the corresponding mix without fibers.

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Subjects

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Modares Civil Engineering journal
Volume 25, Issue 3 - Serial Number 83
July and August 2025
Pages 33-45