凝灰岩机制砂特性对砂浆流动度和强度的影响机理  

Mechanism of Tuff Manufactured Sand Characteristics on Mortar Fluidity and Strengt

作　　者：林高航 陈振光 缪闯波 张春英 宋广明 张利锋 LIN Gaohang;CHEN Zhenguang;MIAO Chuangbo;ZHANG Chunying;SONG Guangming;ZHANG Lifeng(College of Civil Engineering and Architecture,Zhejiang University,Hangzhou 310058,China;Hangwen Project Construction Headquarters,China Railway Shanghai Group Co.,Ltd.,Hangzhou 311215,China;Blooms Hangwen Railway Co.,Ltd.,Hangzhou 311215,China;China Railway 11th Bureau Group Co.,Ltd.,Wenzhou 325115,China)

机构地区：[1]浙江大学建筑工程学院,浙江杭州310058 [2]中国铁路上海局集团有限公司杭温工程建设指挥部,浙江杭州311215 [3]百盛联合杭温铁路有限公司,浙江杭州311215 [4]中铁十一局集团有限公司,浙江温州325115

出　　处：《材料科学与工程学报》2024年第2期205-212,共8页Journal of Materials Science and Engineering

摘　　要：对来自10个不同厂家的凝灰岩机制砂的压碎指标、堆积密度、空隙率、饱和面干吸水率和比表面积等特性进行测试分析,研究各类特性与砂浆流动度、抗压强度和抗折强度的相关性,并分析其内在机理。研究结果表明,机制砂的棱角增大压碎指标值和堆积空隙;母岩岩相和石粉增大机制砂的饱和面干吸水率和比表面积;吸水率差异将严重影响砂浆的流动度及其经时损失,吸水率越大,流动度越小,经时损失越大。当水灰比同为0.5时,机制砂砂浆抗折和抗压强度均高于标准砂配制的砂浆,主要是由于机制砂表面粗糙,机械咬合力强,以及机制砂吸水率相对较大,能有效改善界面过渡区;流动度相同时,对强度的影响程度随流动度大小而变化,流动度为180 mm时,机制砂砂浆强度依然高于标准砂砂浆,但当流动度增大至240 mm时,由于水灰比大幅增加,机械咬合力和界面过渡区优化作用弱化,机制砂砂浆远低于标准砂砂浆的强度。The physical properties including crushing index,bulk density,void fraction,saturated surface dry water absorption and specific surface area of tuff manufactured sand from 10 different manufacturers were determined.The correlations between various characteristics and mortar fluidity,compressive strength and flexural strength were studied,and the internal mechanism was analyzed.The results show that the sharp corners of manufactured sand increase the crushing index and the void fraction.Lithology of the parent rock and fine will affect the saturated surface dry water absorption and specific surface area of the manufactured sand.The difference in saturated surface dry water absorption will not only affect the fluidity of the fresh mortar,but also have influence on the time-varying loss of the fluidity.The greater the saturated surface dry water absorption of sand,the smaller the fluidity of fresh mortar,and the greater the time-varying loss of the fluidity.When the water-cement ratio is 0.5,the flexural strength and compressive strength of manufactured sand mortar are higher than those of standard mortar.The difference in strength is mainly due to two reasons.One is the strong mechanical bite force brought by the rough surface of manufactured sand and the other is the improvement of interfacial transition zone caused by high saturated surface dry water absorption of sands.With the same fluidity,the influence law of mortar’s strength changes with the fluidity value.When the fluidity is 180 mm,the strength of the manufactured mortar is still higher than that of the standard mortar.But,when the fluidity increases to 240 mm,the water-cement ratio increases significantly,the strength of manufactured mortar is far lower than that of standard mortar.

关 键 词：凝灰岩机制砂 流动度 强度比 

分 类 号：TQ172.4[化学工程—水泥工业]