報告題目：Resilience of reinforced concrete structures in corrosive conditions （腐蝕環境下鋼筋混凝土的韌性研究）

報告人：Robert E. Melchers

報告時間：10月21日（星期二）10:00 - 12:00

報告地點：西華大學5A427會議室

主辦單位：材料科學與工程學院

報告人簡介：

Robert E. Melchers, Professor of Civil Engineering (Emeritus), The University of Newcastle, Australia, BE, MEngSC (Monash), PhD (Cambridge, UK), Fellow, Australian Academy of Technology and Engineering. Honorary Fellow, The Institution of Engineers Australia. Awards include 2009 ACA Corrosion Medal, 2012 Jin S Chung Award (ISOPE), 2013 John Connell Gold Medal (The Institution of Engineers, Australia), 2014 Eminent Speaker, Structural College, The Institution of Engineers, Australia, 2006 and 2018 Guy Bengough Award (IOM3).

Robert E. Melchers，澳大利亞紐卡斯爾大學土木工程學院榮譽教授。先后獲莫納什大學工學學士、工程科學碩士及英國劍橋大學博士學位，澳大利亞技術與工程院院士、澳大利亞工程師協會榮譽會士。曾榮膺2009年度澳大拉西亞腐蝕協會腐蝕獎章、2012年國際海洋與極地工程學會(ISOPE) Jin S. Chung獎、2013年澳大利亞工程師協會的最高獎John Connell Medal、2014年澳大利亞工程師協會結構學院杰出演講人稱號，并于2006年及2018年兩度獲英國材料、礦物與采礦學會(IOM3) Guy Bengough獎。

報告內容簡介：

This presentation reviews why reinforced concrete structures, properly made, can endure very aggressive conditions for very long periods of time without reinforcement corrosion or concrete deterioration. Field evidence for this has been available for many years. Laboratory experiments do not always properly represent the behaviour of actual concrete structures. Chlorides are of little importance early in the exposure period. High quality well-compacted, low-permeability concretes eventually deteriorate through the slow outward leaching of concrete alkalis mainly Ca(OH)₂. Its loss is accelerated when chlorides are present. Also reviewed is recent experience with so-called 'carbonation' of concrete. Usually, this is assumed to cause reinforcement corrosion. It is shown that in this case, too, the critical mechanism is the slow loss of Ca(OH)2 by outward leaching. The calcium carbonate layer (carbonation') on the external surface tends to act as a diffusion barrier for such leaching. In addition to these two mechanisms, increasing evidence suggests that reinforcement corrosion may be the result of alkaline-silicate reactivity (ASR) or alkaline-aggregate reactivity (AAR) of the aggregates in the concrete. These break-down of protection of the concrete through break-down and expansion of aggregates.