Title: Flexural Performance and Ductility of Expanded Slate Lightweight Self-Consolidating Concrete Beams

Author(s): Ahmed T. Omar and Assem A. A. Hassan

Publication: Materials Journal

Volume: 119

Issue: 2

Appears on pages(s): 117-129

Keywords: cracking; deflection characteristics; ductility; expanded slate aggregates; flexure; lightweight self-consolidating concrete (LWSCC); serviceability

DOI: 10.14359/51734200

Date: 3/1/2022

Abstract:
This paper investigates the structural performance of large-scale lightweight self-consolidating concrete (LWSCC) and lightweight vibrated concrete (LWVC) beams made with expanded slate coarse aggregates (ESCAs) and expanded slate fine aggregates (ESFAs) under flexural loads. Nine large-scale concrete beams were cast with different types of lightweight aggregate (either ESCA or ESFA), coarse-to-fine aggregate ratios (0.5 to 1.5), and total binder contents (550 and 600 kg/m3 [34.3 and 37.5 lb/ft3]). The structural performance of the tested beams was assessed based on the characteristics of the load-deflection response, cracking pattern, displacement ductility, energy absorption, cracking moment, and ultimate flexural strength. The reliability of code-based expressions in predicting the cracking and ultimate moment capacity of the tested beams was also investigated in this study. The results indicated that using ESFA better improved the beam’s cracking moment capacity, deformability, ductility, and energy absorption capacity compared to using ESCA. Although LWSCC exhibited a lower modulus of elasticity than normal-weight SCC, the deflection values observed in the LWSCC beams under service loads were well within the allowable limit provided by BS 8110. The measured crack widths at the service loads for all tested beams ranged from 0.20 to 0.26 mm (0.008 to 0.01 in.), satisfying the limits proposed by ACI 318, CSA A23.3, and BS 8110 design codes for durability aspects.