To study the effects of fine-aggregates on the drying-shrinkage properties of concrete,two types of manufactured-sand and one type of natural sand(excluding<75μm particles)were selected for tests,and nine sets of ...To study the effects of fine-aggregates on the drying-shrinkage properties of concrete,two types of manufactured-sand and one type of natural sand(excluding<75μm particles)were selected for tests,and nine sets of concrete drying shrinkage tests were designed with three strength grade(C30,C40,and C50)as variables.By observing the drying-shrinkage deformation of the specimens over 360 days,the effects of fine-aggregate properties on the drying shrinkage properties of concrete of different strength grades were analyzed and a prediction model was developed.Compared with natural sand concrete,the development of drying shrinkage of manufactured-sand concrete exhibits the phenomenon of advancement.The apparent density of the fine-aggregate and the strength grade are the two main factors affecting the limit value of the drying shrinkage of concrete.With a reduction in the water absorption or apparent density of the fine-aggregate or the strength grade of concrete prepared using the same fine-aggregate,the prediction accuracy of the existing models decreases.According to the GL 2000 model,two coefficients-and-were introduced to propose a prediction model for the drying shrinkage of fine-aggregate concrete,which is applicable to different strength grades.展开更多
基金Funded by the National Natural Science Foundation of China project(Nos.52108219 and U21A20150)the Lanzhou University of Technology Hongliu Outstanding Young Talent Program,China(No.04-062407)the Research on Quality Control Technology of High-performance Concrete Prepared by Manufactured Sand(No.2020Y21)。
文摘To study the effects of fine-aggregates on the drying-shrinkage properties of concrete,two types of manufactured-sand and one type of natural sand(excluding<75μm particles)were selected for tests,and nine sets of concrete drying shrinkage tests were designed with three strength grade(C30,C40,and C50)as variables.By observing the drying-shrinkage deformation of the specimens over 360 days,the effects of fine-aggregate properties on the drying shrinkage properties of concrete of different strength grades were analyzed and a prediction model was developed.Compared with natural sand concrete,the development of drying shrinkage of manufactured-sand concrete exhibits the phenomenon of advancement.The apparent density of the fine-aggregate and the strength grade are the two main factors affecting the limit value of the drying shrinkage of concrete.With a reduction in the water absorption or apparent density of the fine-aggregate or the strength grade of concrete prepared using the same fine-aggregate,the prediction accuracy of the existing models decreases.According to the GL 2000 model,two coefficients-and-were introduced to propose a prediction model for the drying shrinkage of fine-aggregate concrete,which is applicable to different strength grades.
