The Effect of Incorporating Industrials Wastewater on Durability and Long-Term Strength of Concrete

Abstract

Concrete, as one of the essential construction materials, is responsible for a vast amount of emissions. Using recycled materials and gray water can considerably contribute to the sustainability aspect of concrete production. Thus, finding a proper replacement for fresh water in the production of concrete is significant. The usage of industrial wastewater instead of water in concrete is considered in this paper. In this study, 450 concrete samples are produced with different amounts of wastewater. The mechanical parameters, such as slump, compressive strength, water absorption, tensile strength, electrical resistivity, rapid freezing, half-cell potential and appearance, are investigated, and a specific concentration and impurities of wastewater that cause a 10% compressive strength reduction were found. The results showed that the usage of industrial wastewater does not significantly change the main characteristics of concrete. Although increasing the concentration of wastewater can decrease the durability and strength features of concrete nonlinearly, the negative effects on durability tests are more conspicuous, as utilizing concentrated wastewaters disrupt the formation of appropriate air voids, pore connectivity and pore-size distribution in the concrete.

Influence of Concrete Strength Class on the Long-Term Static and Dynamic Elastic Moduli of Concrete

“…A 8.06% increase in the value of the compressive strength at the age of 365 days (1 year) was reported in [1], whereas a 15.07% increase, at the age of 600 days (1.6 years) was reported in [5]. Neither of the studies had a target compressive strength pertaining to a certain concrete strength class and the water to cement ratio was 0.4.…”

“…Despite economic and sanitary crises, construction markets have continued to expand at a faster or slower pace but are nevertheless growing. According to a recent study, concrete was identified as the second most used commodity in modern society after water [1]. Consequently, it is one of the most intensively studied construction materials.…”

“…However, using metakaolin in combination with polymer admixture has resulted in improving the long-term strength and durability of concrete [6]. Using wastewater as mixing water in concrete was found to have adverse effects on the mechanical properties and durability of concrete in the long run, but the use of industrial treated wastewater had minor negative effects on the abovementioned properties [1]. This represents a significant step forward in reducing the amount of fresh water used in the construction industry.…”