In this study, a new empirical Square-Box test was employed to evaluate the homogeneous flow performance of fiber-reinforced self-consolidating concrete (FR-SCC) under confined-flow conditions that are typical of repair applications. The Square-Box set-up consisted of a closed-circuit box, providing 2.4-m flow distance and a closed-surface cross section of 100-mm width and 200-mm height, equipped with 0 and 4 rows of reinforcing bar grids with 45-mm clear spacing. The flow performance was assessed in terms of dynamic stability and passing ability. The investigated mixtures were considered as diphasic suspensions of fiber-coarse aggregate (F-A > 5 mm) in suspending mortars containing particles finer than 5 mm. According to the experimental results, the dynamic segregation and blocking indices of the investigated mixtures were found in good agreements with characteristics of F-A combination and rheology of mortar. The investigated mixtures exhibited significantly higher blocking indices through the Square-Box set-up compared to those obtained using the L-Box test. Furthermore, the characteristics of F-A and rheology of mortar showed opposite effects on dynamic segregation assessed using Square-Box and conventional T-Box set-ups. Under confined flow conditions, higher dynamic segregation led to more dissimilar compressive strength values at different flow distances through the proposed Square-Box set-up. A new filling ability classification was established based on the experimental dynamic stability and passing ability results of the proposed empirical test.


Civil, Architectural and Environmental Engineering


Université de Sherbrooke, Grant None

Keywords and Phrases

Blocking; Dynamic segregation; Fiber-reinforced self-consolidating concrete; Repair; Rheology; Square-Box test

International Standard Serial Number (ISSN)


Document Type

Article - Journal

Document Version

Final Version

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Publication Date

01 Oct 2022