International Journal of Civil and Structural Engineering Research ISSN 2348-7607 (Online) Vol. 9, Issue 2, pp: (27-37), Month: October 2021 - March 2022, Available at: www.researchpublish.com
THE STUDY OF THE EFFECT OF USING SEAWATER IN FLAT SLABS REINFORCED WITH FIBER REBARS Usama Ali Ali Ebead1, Magdy.M.M Genidi2, Adel M. Soliman3, Asem Elsayed Ali M.Selem4 1
Professor of Reinforced Concrete in Qatar University
2
Associate Professor - Department of Structural Engineering. Faculty of Engineering - Helwan University 3
Assistant Professor of Reinforced Concrete in Obour High Institute for Engineering & technology 4
B. Sc. Civil Engineering 2016 Obour High Institute for Engineering & technology
Abstract: Freshwater, will be scarce and could be very difficult to obtain in some regions of the world. According to the report of the World Meteorological Organization (WMO), more than half of the world’s population will not be able to get enough drinking water by 2025. In the concrete industry, several billion tons of freshwater are used annually in mixing, curing, and cleaning around the world and to saving freshwater, using seawater as the mixing water in concrete should be investigated seriously. So, in this research, we made several mixtures. So, in this research, we made mixtures with different proportions (0%, 50%, 100%) of seawater, and the use of ordinary cement and sulfate-resistant cement, as well as fresh water and seawater in the treatment, and using glass fiber rebar replace steel rebar. The pattern of cracks, final mode of failure, and deformational characteristics (deflection, and steel tensile strain) were recorded. Finally, analysis of test results and recommendations were reported. Keywords: GFRP; seawater; freshwater; and OPC & SRC cement.
1. INTRODUCTION The construction industry and concrete manufacturers realized that they will need to of concrete mixed with seawater use to make an ideal concrete suitable for all Coastal cities. The study found that when seawater is used for mixing or curing concrete, it changes the pace of strength gain. When compared to similar concrete specimens prepared and cured with fresh water at 90 days, the strength of concrete made with seawater was found to be roughly 15% lower. [1]. “Early-age strength performance of seawater concrete was somewhat greater than that of freshwater-mixed counterpart until Day 7, followed by a strength performance that was 7–10 % lower to freshwater concrete after 28 days or later. In addition, seawater concrete shrank slightly more than freshwater concrete, with a difference of 5% recorded after 56 days of mixing.” [2] Seawater is currently forbidden from being used in concrete mixtures due to its high chloride concentration, which promotes reinforcing steel corrosion. The average total salinity of seawater is 3.5 %, with sodium chloride (NaCl) accounting for roughly 78 %. Despite the popular perception that seawater is unsuitable for structural concrete, seawater concrete (seawater-mixed concrete and seawater concrete are used interchangeably in the text) was successfully employed to construct a number of structures during the last century or even earlier. This can be viewed as intuitive proof for the use of seawater in the production of long-lasting concrete. Steel corrosion can be avoided by employing seawater in non-reinforced concrete applications or by reinforcing concrete structures with
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