为了比较分析土壤聚合物和含有矿物掺合料的水泥砂浆的碱-硅反应(ASR)问题。参照我国水工混凝土标准DL/T5151-2001和ASTM C 441-97进行了抑制骨料碱活性效能的试验。试验结果表明:掺加矿物掺合料能够有效地抑制ASR。当5%硅粉、20%粉煤灰...为了比较分析土壤聚合物和含有矿物掺合料的水泥砂浆的碱-硅反应(ASR)问题。参照我国水工混凝土标准DL/T5151-2001和ASTM C 441-97进行了抑制骨料碱活性效能的试验。试验结果表明:掺加矿物掺合料能够有效地抑制ASR。当5%硅粉、20%粉煤灰和40%磨细矿渣共同掺入砂浆时,90d的膨胀率仅有0.13%,即降低了81.9%。对加压挤出的硬化水泥浆体孔溶液进行化学分析,发现矿物掺合料的加入降低了孔溶液中钾、钠离子和氢氧根离子的浓度,这是减少ASR危害的根本原因。土壤聚合物是一种无定形的无机材料,由偏高岭土、硅粉在高碱条件下制得。土壤聚合物的碱含量很高,达到12.1%,但土壤聚合物砂浆没有产生任何膨胀,其原因是土壤聚合物中没有充足的游离碱与活性骨料反应,因此不会产生危害性ASR。展开更多
This paper presents a comprehensive review of modeling of alkali-silica reaction(ASR)in concrete.Such modeling is essential for investigating the chemical expansion mechanism and the subsequent influence on the mechan...This paper presents a comprehensive review of modeling of alkali-silica reaction(ASR)in concrete.Such modeling is essential for investigating the chemical expansion mechanism and the subsequent influence on the mechanical aspects of the material.The concept of ASR and the mechanism of expansion are first outlined,and the stateof-the-art of modeling for ASR,the focus of the paper,is then presented in detail.The modeling includes theoretical approaches,meso-and macroscopic models for ASR analysis.The theoretical approaches dealt with the chemical reaction mechanism and were used for predicting pessimum size of aggregate.Mesoscopic models have attempted to explain the mechanism of mechanical deterioration of ASR-affected concrete at material scale.The macroscopic models,chemomechanical coupling models,have been generally dcveloped by combining the chemical reaction kinetics with linear or nonlinear mechanical constitutive,and were applied to reproduce and predict the long-term behavior of struetures suffering from ASR.Finally,a conclusion and discussion of the modcling are given.展开更多
文摘为了比较分析土壤聚合物和含有矿物掺合料的水泥砂浆的碱-硅反应(ASR)问题。参照我国水工混凝土标准DL/T5151-2001和ASTM C 441-97进行了抑制骨料碱活性效能的试验。试验结果表明:掺加矿物掺合料能够有效地抑制ASR。当5%硅粉、20%粉煤灰和40%磨细矿渣共同掺入砂浆时,90d的膨胀率仅有0.13%,即降低了81.9%。对加压挤出的硬化水泥浆体孔溶液进行化学分析,发现矿物掺合料的加入降低了孔溶液中钾、钠离子和氢氧根离子的浓度,这是减少ASR危害的根本原因。土壤聚合物是一种无定形的无机材料,由偏高岭土、硅粉在高碱条件下制得。土壤聚合物的碱含量很高,达到12.1%,但土壤聚合物砂浆没有产生任何膨胀,其原因是土壤聚合物中没有充足的游离碱与活性骨料反应,因此不会产生危害性ASR。
基金The authors acknowledge the support of the National Key Basic Research Program of China(Nos.2010CB731504 and 2011CB013602)the research funding from the State Key Laboratory of Hydroscience and Engineering,Tsinghua University(No.2010-TC-1).
文摘This paper presents a comprehensive review of modeling of alkali-silica reaction(ASR)in concrete.Such modeling is essential for investigating the chemical expansion mechanism and the subsequent influence on the mechanical aspects of the material.The concept of ASR and the mechanism of expansion are first outlined,and the stateof-the-art of modeling for ASR,the focus of the paper,is then presented in detail.The modeling includes theoretical approaches,meso-and macroscopic models for ASR analysis.The theoretical approaches dealt with the chemical reaction mechanism and were used for predicting pessimum size of aggregate.Mesoscopic models have attempted to explain the mechanism of mechanical deterioration of ASR-affected concrete at material scale.The macroscopic models,chemomechanical coupling models,have been generally dcveloped by combining the chemical reaction kinetics with linear or nonlinear mechanical constitutive,and were applied to reproduce and predict the long-term behavior of struetures suffering from ASR.Finally,a conclusion and discussion of the modcling are given.
