Improving the durability of organic matter in cement-treated sludge using metakaolin and lime

Abstract

Solidified sludge, a potentially useful engineering material, contains organic matter that decomposes, releasing humic acid. The resultant corrosion reduces the compressive strength of the solidified sludge. This can be ameliorated by adding small quantities of lime and cement, which creates a strongly alkaline environment; unfortunately, the improvement is not long-lasting. We attempted to counteract this by adding metakaolin, which can capture calcium ions and form a stable binder in the solidified soil. The resulting material proved strongly resistant to the erosive effect of humic acid, improving and maintaining the durability throughout the curing period (180 days).

Keywords:

• Sludge
• metakaolin
• humic acid
• lime
• cementitious
• cement
• durability

Correction Statement

This article has been republished with minor changes. These changes do not impact the academic content of the article.

Additional information

Funding

This work was supported by the National Natural Science Foundation of China (51979150), the Youth Innovation Team Project of Hubei province (T201803), and the Special Program of Central Financial Ministry for Supporting Local College Development (2016).