The long-term performance of concrete amended with municipal sewage sludge incineration ash

Municipal sewage sludge incineration ash (MSSIA) is commonly used as a raw material in concrete, but few studies have focused on the long-term environmental tolerance of municipal sewage sludge incineration ash concrete (MSSIAC). In this study, acid rain leaching, salt erosion, and freezing-thawing tests were used to evaluate the long-term environmental behavior of the optimal MSSIAC formulation. One optimal MSSIAC formulation replaces 5% MSSIA, and results in a 7.2% increase in unconfined compressive strength (UCS), indicating that MSSIA-amended concrete can have enhanced UCS. Only Zn was released from the optimal MSSIAC formulations (replacing 5% or 10% MSSIA) in the acid rain leaching test, but only up to 0.071 mg Zn L-1, which was within the acceptable environmental range. No heavy metals were released at concentrations above the method detection limits in the salt erosion and freezing-thawing tests. The optimal MSSIAC formulations have excellent long-term environmental tolerance while meeting the requirement of UCS, and provide a valuable use for MSSIA. (C) 2021 Elsevier B.V. All rights reserved.

Automated summary

The study assessed the long-term environmental performance of municipal sewage sludge incineration ash concrete, finding that the optimal formulation can increase unconfined compressive strength and release heavy metals within acceptable environmental ranges.