Nitrite admixed concrete for wastewater structures: Mechanical properties, leaching behavior and biofilm development

This study systematically investigated the impacts of calcium nitrite addition on the mechanical properties and biofilm communities of concrete-based wastewater infrastructures using sulfate resistant cement through standard tests and DNA sequencing, respectively. The results revealed that setting time and water demand for normal consistency were reduced, but slump, drying shrinkage, and apparent volume of permeable voids increased with calcium nitrite dosage up to 4% weight of cement. The cumulative leached fraction of nitrite, 28-day compressive strength and biofilm communities were not significantly affected by calcium nitrite dosages. The addition of calcium nitrite into concrete is environmentally friendly to wastewater infrastructures.