摘要
人工砂表面粗糙,石粉颗粒细小,增大混凝土的用水量,增大混凝土开裂的倾向,另一方面,人工砂具有增大混凝土强度的特性,可减小混凝土开裂的倾向,因此对人工砂混凝土的抗裂性能有必要进行全面的研究。对人工砂与河砂混凝土的早期和硬化后的抗裂性能进行了系统研究。研究发现,人工砂混凝土最大裂缝宽度、24h裂缝数量、单位面积的裂缝数量和单位面积上的总开裂面积均较河砂混凝土大,早期抗裂能力较小;硬化后的人工砂混凝土抗压强度、抗拉强度、极限拉伸值及抗裂能力指数较大,线膨胀系数、弹强比和热强比较小,有利于减小温度应力,提高混凝土抵抗温度裂缝的能力;干缩稍大,非大体积混凝土抗干缩开裂的能力减小。
With rough surface and very fine powder particles,manufactured sand increases the water consumption and cracking tendency of concrete.On the other hand,manufactured sand can increase the strength,so as to reduce the cracking tendency of the concrete.Therefore,it is necessary to make a comprehensive study of the anti-cracking performance of manufactured sand concrete.In this paper,the anti-cracking performance of early and hardened manufactured sand and natural sand concrete are systematically studied.Results indicate that,maximum crack width,24hfracture quantity,the crack quantity of unit areas and the whole cracking area of unit areas of manufactured sand concrete are more than natural sand,the early crack resistance is greater than natural sand concrete.Compressive strength,tensile strength,ultimate tensile elongation and crack resistance index of manufactured sand concrete are bigger than natural sand,while the coefficient of linear expansion,module-strength ratio and heat-strength ratio is smaller.Those make for reducing the temperature stress and increasing the temperature crack resistance capability.Dry shrinkage is slightly bigger than natural sand,dry shrinkage cracking resistance is smaller than natural sand in non-large volume concrete.
出处
《中国农村水利水电》
北大核心
2013年第8期99-102,共4页
China Rural Water and Hydropower
基金
广东省水利科技创新项目(2006-10#)
乐昌峡水利枢纽工程管理处资助
关键词
人工砂混凝土
河砂混凝土
抗裂性能
manufactured sand concrete
natural sand concrete
anti-cracking performance
comparison
