An assessment of electrochemical chloride extraction as a remediation technique for steel reinforced concrete

Steel reinforced concrete blocks were subjected to chloride extraction after they were dosed with either NaCl or CaCl2. All the blocks were then exposed to the elements at the BRE exposure site for a total period of about 6 years. The steel reinforcement was regularly monitored electrochemically to determine its level of corrosion. Core samples were also analysed before and after treatment to determine the chloride concentration profiles. A selection of blocks were cut into smaller steel-containing prisms after 4 ½ years of exposure and were exposed to controlled laboratory conditions for 6 months while determining the level of corrosion electrochemically. At termination, each steel bar was removed and examined visually. The total weight loss was assessed gravimetrically. The final chloride concentration profile of each prism was also determined. Results suggested that corrosion was reduced significantly following chloride extraction but that the primary long-term controlling factor, both for the desalinated and control specimens, appeared to be the level of chloride present at the depth of the steel reinforcement. As, under normal procedures, a proportion of chloride remains after chloride extraction, a significant level of corrosion of the reinforcement, although greatly reduced, is still likely

The long-term effectiveness of electrochemical chloride extraction as remediation for corroding steel in reinforced concrete

Steel reinforced concrete blocks were subjected to electrochemical chloride extraction after they were dosed with chlorides. Following treatment, the blocks were exposed to the elements at the BRE exposure site for a period of up to 6 years. A selection of blocks were cut into smaller steel-containing prisms after 4 ½ years of exposure and were exposed to controlled laboratory conditions for 6 months while determining the level of corrosion by linear polarisation. At termination, each steel bar was removed and examined visually. The level of corrosion of each bar was also assessed gravimetrically. The final chloride concentration profile of each prism to a depth beyond the steel bars was also determined. Results suggested that corrosion was reduced significantly following chloride extraction but that the primary controlling factor, both for the desalinated and control specimens, was the level of chloride present at the depth of the steel reinforcement. Coating the concrete after treatment resulted in an overall increase in corrosion level, possibly because the coatings were not coherent and allowed moisture to penetrate the concrete through cracks and defects which could not subsequently escape owing to the coating

Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries

Background Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres. Methods This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries. Results In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia. Conclusion This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries