دانلود رایگان مقاله انگلیسی مشارکت الیاف گیاهی در بهبود رفتار و ظرفیت بتن مسلح برای برنامه های ساختاری - الزویر 2018

abstract

Plant fibers (especially, wheat straw) are available surplus to requirements in sub-tropical regions. Many researchers have studied these fibers for non-structural applications. However, for civil engineering structural applications, in depth behavior of wheat straw reinforced concrete (WSRC) with steel rebars is not known. For this purpose, WSRC needs to be explored in detail for load bearing structures. This paper presents the contribution of plant fibers (i.e. wheat straw) in improving the behavior and capacity of reinforced concrete for structural applications. Reinforced concrete beam-lets with varying flexure and shear rebars, without and with inclusion of wheat straw, are experimentally investigated for studying the altered behavior due to fibers. In addition, to start with the practical implications, concrete pavements are considered. The study is concluded with an increase in flexural strength (up to 7.5%), energy absorption (up to 30.4%), and toughness indices (up to 11.1%) along with better crack arresting mechanism by incorporation of wheat straw in reinforced concrete. Also, concrete pavement containing wheat straw has comparable design with likely more durable and sustainable structure.

Conclusions

The plant fibre (i.e. wheat straw) in concrete with flexural and shear reinforcement are investigated in this experimental study. Straw of 1% content, by mass of wet concrete, and length of 25 mm are added in the same mix (i.e. 1:2:4) as for PC. The contribution of plant fibre (i.e. wheat straw) is studied for improving the capacities and behavior of concrete reinforced with flexural and shear steel rebars for its use in concrete pavements. Plain Concrete (PC), and Wheat Straw Reinforced Concrete (WSRC) with the flexural and shear reinforcement are studied. In addition to this, the moment capacity design equation and concrete pavement thickness design equation are also proposed. The conclusions are as follows:

A maximum load increase of 7% in the first crack initiation is observed for WSRC with flexural rebars as compared to that of PC. And the maximum load is increased by 7.6% in comparison to PC. In WSRC, the number of cracks, crack widths, and crack lengths are decreased up to 25%, 140% and 66%, respectively, when compared to the respective PC specimens.

WSRC with flexural reinforcement show enhancement up to 7.5%, 44.8%, 30.4%, and 11.7% in FS, FEP, FE, and FTI, respectively, as compared to the respective PC beam-lets. The moment capacities of WSRC with flexural and shear rebars are increased up to 2.8% and 2%, respectively, in comparison to that of PC.