机制砂颗粒分计筛余量对混凝土性能的影响  

Effect of Graded Sieve Residue Content in Manufactured Sand on Concrete Performance

作　　者：罗紫隆 刘会中 胡翠 杨智卓 

机构地区：[1]咸阳海螺新材料科技有限公司,陕西咸阳713201 [2]北京建工资源循环利用股份有限公司,北京100083

出　　处：《混凝土世界》2025年第4期15-19,共5页China Concrete

摘　　要：机制砂特性的变化对混凝土拌合物各项性能指标的影响不尽相同,本文采用同类定量比较法,按照级配区间重组出具有各区间代表性的样品作为基点,用来模拟实际应用生产过程中机制砂颗粒级配发生变化时,对新拌混凝土工作性、力学性能及体积稳定性的影响;研究0.6 mm以下细集料的不同占比(不明显影响颗粒级配数值)对新拌混凝土工作性、力学性能及体积稳定性的影响,获得石粉掺量的极限值。结果表明:机制砂分级粒径在2.36 mm以上时,颗粒过多会影响混凝土的粘聚性和保水性;颗粒过少会降低混凝土拌合物的力学传导效率和流速。机制砂分级粒径在0.6~1.18 mm时,是混凝土的流速及填充关键数量,颗粒数量过少时,混凝土的流速慢、粘度大;颗粒数量过多则混凝土的保水性较差。机制砂分级粒径在0.3 mm以上时,主要会影响混凝土中砂浆的饱满度和粘结强度。机制砂分级粒径在0.6 mm以下时,随着该区间颗粒含量的上升,混凝土的初始坍落度和扩展度呈先增加后降低的趋势,保水性提升,胶凝材料用量先减少后增加,同时混凝土的体积变化及收缩也呈先减小后增大的趋势,并随着细度的减小,混凝土的凝结时间会有所缩短。The changes in the character istics of manufactured sand have varying effects on the performance indicators of concrete mixtures.This paper employs a similar quantitative comparison method,reorganizing representative samples from each grading interval as reference points to simulate the effects of changes in the particle size distribution of manufactured sand during actual production processes on the workability,mechanical proper ties,and volume stability of fresh concrete.The study investigates the impact of different proportions of fine aggregates below 0.6 mm(which do not significantly affect the particle size distribution values)on the work ability,mechanical properties,and volume stability of fresh concrete,aiming to determine the optimal stone powder content.The results show that when the graded particle size of manufactured sand exceeds 2.36 mm,too many particles can affect the cohesion and water retention of concrete;too few particles will reduce the mechanical conduction efficiency and f low rate of the concrete mixture.When the graded particle size of manufactured sand is between 0.6 and 1.18 mm,it is crucial for the f low rate and filling capacity of concrete.If the number of particles is too low,the f low rate slows down and the viscosity increases;if there are too many par ticles,the water retention decreases.When the graded par ticle size of manufactured sand is above 0.3 mm,it primarily affects the fullness and bonding strength of the mortar in concrete.When the graded particle size of manufactured sand is below 0.6 mm,as the particle size content increases,the initial slump and spread of concrete first increase and then decrease,with improved water retention.The amount of cementitious materials initially decreases but then increases,and the volume change and shrinkage of concrete also show a trend of first decreasing and then increasing.As the fineness decreases,the setting time of concrete shortens.

关 键 词：分计筛余比例 流动性 体积稳定性 强度 石粉 

分 类 号：TU528.041[建筑科学—建筑技术科学]