工业和农业废弃物在混凝土中的本地资源化利用:可持续解决方案（英文）

Utilization of Locally Available Industrial and Agro-Industrial Wastes in Concrete:A Sustainable Solution

全球变暖是当今社会面临的主要环境问题，是由过量二氧化碳排放造成的。水泥生产过程中石灰石的分解和燃料的燃烧排放的CO2量占据了总排放的5％～8％。随着民用基础设施建设的快速发展，特别是在中国、印度、中东等发展中国家，水泥和混凝土使用量飞速增长。采用辅助胶凝材料替代混凝土中水泥的使用量，尤其是工业废弃物，能够显著降低了混凝土生产过程中的碳排放。普通的工业废弃物，如硅灰、粉煤灰、矿粉等并不是全部可以利用的，较远距离运输会造成CO2总排放量的增加。然而，铝生产工业的其他副产物和废弃纸泥灰也可以作为辅助胶凝材料进行循环利用的。农业生产中的废弃物，如甘蔗灰、棕榈油灰、椰子壳灰、稻壳灰等也有火山灰特性，能够将其作为辅助胶凝材料使用。此外，一些天然掺合料，如硅藻土含有丰富的火山灰活性组分。近年来，玻璃粉作为辅助胶凝材料在很多国家广泛应用。上述辅助胶凝材料的循环利用能够降低混凝土对环境影响，且能有效减少相关生产费用。

Global warming--one atmosphere. The cement industry decomposition advanced civil of limestone and of the major issues we face today--is caused by the emission of greenhouse gases into the contributes conservatively 5%-8% of global carbon-dioxide （CO2） emissions, mainly through the combustion of fossil fuels during cement production. With the rapidly increasing demand for y in China, India, the Middle East, and the developing world--the cement and concrete industries are expected to expand significantly. Replacing part of the cement content in concrete with supplementary cementitious materials （SCMs）----generally industrial by-products--has significantly reduced concrete＇s carbon footprint. Yet ordinary SCMs, such as silica fume, fly ash, and slag, are not universally available, adding CO2 costs related to transportation. Other by-products from the aluminum industry （i.e., glass frit resulting from the processing of spent pot liners） and wastepaper-sludge ash （WSA） can be recycled in concrete as alternative SCM. Agricultural wastes such as sugarcane bagasse ash （SCBA）, palm-oil fuel ash （POFA）, coconut-shell ash （CSA）, corn-cob ash （CCA）, rice-husk ash--which are locally available in many tropical countries--have demonstrated pozzolanic properties, allowing their use as alternative cementitious materials. Some natural minerals like diatomaceous earth, whichare available in many regions, are known for their good pozzolanicity. More recently, glass powder obtained from grinding waste bottle glass largely available in some countries has been introduced as an alternative SCM. The recycling of these alternative SCMs can reduce both concrete＇s environmental impact and its related production cost.