此处为讲稿文本内容哦！6a.Youaregoingtogiveatalkoncomposites（复合材料）technolotyataconstructionmaterialstradefair（建材交易会）.Inpartofthetalk,youfocusonreinforcedconcrete（钢筋混凝土）asawell-knownexampleofacompositematerial（复合材料）.Prepareyourtalkusingwordsandphrasesfromthissectionandthefollowingnotes.CompositematerialsCommonexample:reinforcedconcrete （钢筋混凝土）(verywidelyusedcomposite)Cement水泥(derivedfromlime石灰)Aggregate骨料---fineaggregate细骨料(sand)+coarseaggregate粗骨料(gravel砂砾orcrushedstone碎石)Water+chemicaladditives(e.g.plasticiser塑化剂toimprveworkablility可施工性)Reinforcement钢筋(steelbars条钢,fixedtogetherwithsteeltiewire)