针片状颗粒对高强混凝土性能的影响研究  

Study on the Influence of Elongated and Flaky Particles on the Performance of High Strength Concrete

作　　者：宋少民[1] 卢超琦 SONG Shaomin;LU Chaoqi(Beijing Key Laboratory of Building Structure and Environmental Remediation Functional Materials,Beijing University of Civil Engineering and Architecture,Beijing 100044,China)

机构地区：[1]北京建筑大学,建筑结构与环境修复功能材料北京市重点试验室,北京100044

出　　处：《粉煤灰综合利用》2024年第4期21-26,共6页Fly Ash Comprehensive Utilization

摘　　要：从粗骨料针片状颗粒角度出发,研究其含量和粒径对高强混凝土性能的影响。选取掺加5%、15%和25%针片状颗粒含量的粗骨料配制混凝土,对混凝土的工作性能、力学性能和耐久性能进行试验研究;选取5~10 mm、10~16 mm和16~20 mm共三种粒径区间的针片状颗粒,探究粒径大小对混凝土性能的影响规律。结果表明:针片状颗粒含量增加,高强混凝土和易性和泵送性能变差,混凝土抗压强度降低,混凝土收缩增大,且对高强混凝土耐久性能不利;混凝土拌合物坍落度和扩展度、硬化混凝土各龄期抗压强度均随着粗骨料中针片状颗粒粒径增大而降低;综合考虑针片状颗粒对高强混凝土性能影响规律,建议控制针片状颗粒含量不超过5%;同时,在计算针片状颗粒含量时,需在标准计算方法基础上按不同粒径针片状颗粒分别乘以其对应的影响系数进行修正,以实现对粗骨料粒形更好的控制。From the perspective of coarse aggregate elongated and flaky particles,the effect of its content and particle size on the properties of high strength concrete was investigated.The concrete was prepared with four kinds of coarse aggregates with 5%,15%and 25%of the content of elongated and flaky particles,and the working,mechanical and durability properties of the concrete were investigated,and three kinds of elongated and flaky particles in the size range of 5-10 mm,10-16 mm and 16-20 mm were selected to investigate the influence of the size on the performance of the concrete.The results show that the increase in the content of elongated and flaky particles,high-strength concrete ease and pumping performance deterioration,concrete compressive strength decreased,concrete shrinkage increased,and the durability of high-strength concrete is unfavourable;concrete mix slump and expansion,hardened concrete compressive strength at various ages with the increase in the size of the elongated and flaky particles in the coarse aggregate and reduce.Considering the influence of elongated and flaky particles on the performance of high-strength concrete,it is suggested to control the content of elongated and flaky particles not more than 5%;at the same time,when calculating the content of elongated and flaky particles,it is necessary to multiply the influence coefficients of elongated and flaky particles of different particle sizes on the basis of the standard method of calculation,so as to achieve a better control on the particle shape of the coarse aggregates.

关 键 词：粗骨料 针片状颗粒 高强混凝土 性能影响 

分 类 号：TU528.041[建筑科学—建筑技术科学]