Indexed by:期刊论文
Date of Publication:2018-11-01
Journal:COMPUTERS AND CONCRETE
Included Journals:SCIE、Scopus
Volume:22
Issue:5
Page Number:481-492
ISSN No.:1598-8198
Key Words:new hybrid fiber system; slab; CaCO3 whisker; flexural toughness; reinforcing index; scanning electron microscopy
Abstract:In this paper, a new hybrid fiber system (NHFS) is investigated for the application of slab. The steel fiber, polyvinyl alcohol (PVA) fiber and calcium carbonate (CaCO3) whisker is added to form NHFS. The four-point bending test is carried out on the flexural properties of slab with plain, steel fiber, traditional hybrid fiber system (THFS) and NHFS reinforced cementitious composites. The flexural behavior is evaluated by ASTM C1018-97, JCI-SF4 and post-crack strength (PCS) technique. The evaluation parameters of flexural toughness such as toughness index (TI), equivalent flexural strength (EFS) and PCS are determined. The size of slab specimens is 15 mm (thickness)x 50 mm (width)x200 mm (length). The results show that adding CaCO3 whisker to THFS can significantly improve the flexural strength, TI, EFS, PCS of the slab. The empirical relation between reinforcing index (RIv) and flexural parameters show that flexural parameters of slabs increase first and then decrease; which indicates that optimum RIv values can be helpful in the considering the mix design of steel-PVA fibers-CaCO3 whisker composites for achieving the desired flexural-related properties. The scanning electron microscopy is performed to observe the micro-morphological characteristics of the fracture surface, which proved the positive hybrid effect among the different fibers in cementitious composites. The NHFS can arrest the generation and propagation of the crack from micro to macro level.