Impact of treated industrial wastewater's pH on different characteristics of self-compacting concrete

Abstract

The study investigated the impact of varying pH levels on the workability, mechanical, and durability properties of self-compacting concrete (SCC) when treated industrial wastewater (TIWW) from the Tehran oil refinery was utilized. Eight different SCC specimens were made, two control specimens applying potable water with a water-to-cement ratio (w/c) of 0.5 with 400 kg/m3 of cement and w/c of 0.36 with 440 kg/m3 of cement. Using TIWW instead of potable water decreased the slump flow of concretes. Raising the pH of treated industrial wastewater (TIWW) from acidic to alkaline conditions enhances the slump flow of self-consolidating concrete (SCC). Applying TIWW in SCC increased T50 compared to potable water. Growing pH of TIWW from 5 to 9, T50 increased. Nevertheless, elevating the pH from 5 to 9 in the treated industrial wastewater (TIWW) resulted in a slight increase in the L-box of the SCC. The usage of TIWW instead of potable water in concrete decreased compressive and flexural strengths. Increasing the pH of TIWW from 5 to 9 in SCC samples increased the compressive and flexural strengths for both SCC mixture designs. Using TIWW instead of potable water slightly increased 30-min, one-hour water adsorption, capillary water adsorption, and carbonation depth.

Keywords

• pHs
• Self-compacting concrete
• Treated industrial wastewater
• Mechanical and durability properties