Skip to main navigation Skip to search Skip to main content

Pretreated lightweight aggregates for self-healing concrete exposed to calcium hydroxide-rich sewage

  • Harbin Institute of Technology
  • School of Civil Engineering, Harbin Institute of Technology

Research output: Contribution to journalArticlepeer-review

Abstract

Concrete pipes are prone to cracking, causing deterioration in durability. To construct sewage pipes with a self-healing ability in specific environment, this study investigated the self-healing behavior of the mortar containing pretreated lightweight aggregates in calcium hydroxide-rich sewage, and revealed the healing mechanism. Ceramsites were previously treated by impregnating with sodium silicate and encapsulating. Then, the mortar mixed with pretreated ceramsites was pre-cracked and exposed to water, Ca(OH)2 solution and Ca(OH)2 solution/dry cycles. The healing efficiency was evaluated by the recovery rate of compressive strength, reduction rate of sorptivity coefficient and evolution rate of cracks. Results showed that the mortar exposed to Ca(OH)2 solution/dry cycles exhibited the most dominant healing efficiency. After healing for 30 days, the recovery rate of strength and reduction rate of sorptivity coefficient reached approximately 70 %. The closure rate and area healing rate of the crack of 0–250 μm in width exceeded 80 %. SEM and EDS indicated that healing products were mainly C[sbnd]S[sbnd]H gel and calcite. The accumulation and filling of products made crack self-healing, thereby improving the durability of cracked mortar.

Original languageEnglish
Article number130117
JournalConstruction and Building Materials
Volume365
DOIs
StatePublished - 15 Feb 2023

Keywords

  • Crack change rate
  • Microanalysis
  • Pretreated ceramsites
  • Self-healing
  • Sewage exposure
  • Sodium silicate

Fingerprint

Dive into the research topics of 'Pretreated lightweight aggregates for self-healing concrete exposed to calcium hydroxide-rich sewage'. Together they form a unique fingerprint.

Cite this