Some Considerations for Applicability of Seawater as Mixing Water in Concrete

Abstract

According to the report of the WMO, more than half of world population would not have enough drinking water by 2025. In order to save drinking water, the usage of seawater in concrete industry seems imperative. In the present study, the possibilities of seawater as a material of concrete were discussed based on the literature-based and experimental investigations. As the results of literature-based study, more than half of papers collected in this study had positive opinion about concrete mixed with seawater by adding the mineral admixture such as blast furnace slag (BFS). Also some results of long term exposure tests indicated the high possibility of utilization of seawater as a material of concrete. Moreover the experimental data obtained in this study indicated that the addition of BFS might contribute significantly to the corrosion resistance of steel bar due to low oxygen environment around steel bar as well as chloride immobilization. INTRODUCTIONSThe rapid growth of world population, in addition to the climate change may have serious impacts on resources around the world. Fresh water for example will be a scarcity and it might be very difficult to obtain it at some regions in the world. According to the report of World Meteorological Organization (WMO), more than half of the world population would not be able to get enough drinking water by 2025.Here, in concrete industry, several billion tons of fresh water is annually used, as mixing, curing and cleaning water, around the world. From the view point of saving fresh water, the authors believe that the possibilities of using seawater as mixing water in concrete should be investigated seriously. Additionally, if the use of seawater as a concrete material is permitted, it will be very convenient and economical in the construction, especially in the coastal works. However, in most of the reinforced concrete standards, the use of seawater is not permitted due to the risk of early corrosion of reinforcement, induced by Cl in seawater compounds.Third International Conference on Sustainable Construction Materials and Technologies http://www.claisse.info/Proceedings.htm LITERATURE-BASED INVESTIGATIONSOutline of literature survey. First of all, the published papers related to concrete mixed with seawater were analysed. These papers were collected by the data base of Japan Science and Technology Agency (JST), and published from 1974 to 2011. During this literature survey, a total of 68 papers (English: 32 papers, Japanese: 36papers) have been analysed. The distribution of annual publication on this topic is shown in Figure 1. Throughout this figure, it can be understood that the investigation of concrete mixed with seawater has been conducted so far, more than 40 years, with almost constant number of publications per year.

Application of Seawater and Sea Sand to Develop Geopolymer Composites

“…The compressive strength of geopolymer concrete increase as the curing temperature increased was observed. Similar observations were shown by past research[17].…”

“…This is also a great issue for lives on the planet. It is also said that in 2025 half of humanity will live in the areas where fresh water is not enough [17]. One solution to this predicament is to utilize sea water to substitute fresh water in concrete casting.…”

“…T et al [30] The introduction of blast furnace slag might contribute significantly to the corrosion resistance of steel bar. 30 11. Mohammed T.U.…”

Influence of seawater and blast furnace cement employment on recycled aggregate concretes’ properties

“…The use of freshwater in concrete production causes a serious impact on areas where it represents a scarce resource. However, researchers' opinion concerning the suitability of using seawater in concrete is still divided [27]. Although the high risk of corrosion implied in the use of seawater in the production of reinforced concrete has led to its prohibition by various international standard regulations, it has been allowed in plain concrete manufacture under the proviso that it complies with the given standards criteria of the pertinent regulation [28][29][30].…”

Durability of Seawater Mixed Concrete with Different Replacement Ratio of BFS (Blast Furnace Slag) and FA (Fly Ash)

“…chloride attack [3]. Therefore, the authors conducted this study to evaluate the durability performance of sea water mixed concrete with different cement replacement ratio of BFS (blast furnace slag) and FA (fly ash) against chloride attack.…”