Effects of mixing water salinity on the properties of concrete

Abstract

The use of seawater and sea-sand in producing concrete has attracted increasing research attention in recent years to address the shortage of river sand and in certain applications the shortage of freshwater. In particular, reinforced concrete structures made of seawater sea-sand concrete (SSC) and corrosion-resistant fiber-reinforced polymer (FRP) are particularly attractive for the development of coastal and marine infrastructure (e.g. on remote islands) as durable structures can be created using locally available materials. Existing studies on SSC or seawater concrete have been largely limited to the use of mixing water with a salinity level close to the world-average ocean salinity. Against this background, the present paper reports the first ever systematic study on the effect of salinity of mixing water on the properties of concrete. The present study covered a wide range of salinity levels from 16.5 g/L to 82.5 g/L, and examined a wide range of short-term concrete properties including the heat of hydration, shrinkage, compressive strength and modulus of elasticity. The test results show that the salinity of mixing water has a considerable effect on the rate of hydration heat and shrinkage at early ages, as well as the cumulative release of hydration heat. It is also shown that the water salinity has a slight negative effect on the compressive strength and modulus of elasticity of concrete at ages older than 14 days.

Evaluation of different strategies for efficient sporulation and germination of the MICP bacterium Lysinibacillus sphaericus strain MB284 (ATCC 13805)

“…The salinity of pore solutions in concrete varies depending on the salt content of the water and the sand which are used in its production, which can be as high as ∼ 90 g/l when seawater and sea-sand are used [24]. Although growth was observed to be higher in MSM, which has a higher concentration of ions than the EZi medium (Figure 4), it is unclear how halotolerant strain MB284 is [25].…”

Workability, strength, and shrinkage of ultra-high-performance seawater, sea sand concrete with different OPC replacement ratios

“…Due to the presence of excessive sodium and calcium chloride in seawater sea sand concrete, the morphology of the pore structure densifies, which increased the number of micropores. This eventually increases the capillary tension and therefore generates substantially high drying shrinkage [60,61]. Additionally, the presence of seashell contents may have accounted for larger drying shrinkage in sea sand-based concrete, particularly due to the lower rigidity of sea-shell particles [62].…”

A Systematic Literature Review on the Effect of Seawater as A Promising Material on the Physical and Mechanical Performance of Concrete

“…Nonetheless, the chloride content in seawater would affect the performance of the concrete over time and lead to a decrease in workability, durability, long-term strength, and the worst situation is the collapse of the structural element (Xiao et al, 2017). A lower water-cement ratio was also used in seawater concrete because the salinity of the seawater was found to affect the overall performance of the concrete (Dhondy et al, 2021). In addition, the use of seawater would slightly reduce the slump and spread of cement paste generated in the concrete mixture compared to Da B et al, 2021;Li et al, 2021;Yue C et al, 2021;Dhondy et al, 2020;He X et al,2020;Yin et al, 2020;Parvizi et al, 2020;Chen G et al, 2020;Mansyur & Permana, 2020;Ma H et al, 2020;Gao et al, 2020;Soares et al, 2020;Adnan et al, 2020;Li, L. G., et al, 2019;;Montanari L. et al, 2019;Yu H et al, 2019;Gong W et al, 2019;Madona & Sivakumar, 2019;Jiang et al, 2019;Younis et al, 2019;Tan Y et al, 2018;Younis et al, 2018;Duan et al, 2015) Flexural strength 5 Gao et al, 2020;Parvizi et al, 2020;Jiang et al, 2019;Duan et al, 2015) Splitting tensile strength 4 (Ting M.Z.Y.…”

“…13(Ting M. Z.Y. et al, 2021;Dhondy et al, 2021;Sun et al, 2021;Gao et al, 2020;Parvizi et al, 2020;Ting M. Z. Y et al, 2020;Chen G et al, 2020;Soares et al, 2020;Li, L. G., et al, 2019;Younis et al, 2018;Xiao et al, 2017;Duan et al, 2015) Fig.4 -…”