摘要
为研究混凝土在轴压荷载作用下的碳化性能,设计了1种轴压加载装置,对普通混凝土以及掺量为30%的粉煤灰混凝土在应力比为0、30%、45%、60%的轴压荷载和二氧化碳浓度为2%、20%耦合作用下进行了试验研究,分析轴压荷载应力比和二氧化碳浓度对两种混凝土碳化深度的影响。结果表明:在相同轴压荷载和二氧化碳浓度作用下,相比于粉煤灰混凝土,普通混凝土的抗碳化性能更好一些;与单一碳化因素作用组相比,不同大小的轴压荷载与碳化耦合对粉煤灰混凝土碳化深度的影响表现为以下规律:高应力比加速了粉煤灰混凝土的碳化过程,低应力比则是起到抑制的作用,应力比由0增大到0.3再到0.6,粉煤灰混凝土的28 d碳化深度前者减小了18%,后者增长了25%,总体呈现先减小后增大的趋势;混凝土的碳化深度与碳化龄期和二氧化碳浓度均呈正相关关系,且在碳化初期增长较快,两种二氧化碳浓度下前7 d粉煤灰混凝土的碳化深度均能达到快速碳化28 d的65%。
In order to study the carbonation performance of concrete under the axial compression load,it designed an axial compression loading device.Under the coupling action of axial loading with stress ratio of 0,30%,45% and 60% and CO2concentration of 2% and20%,the experimental research was carried out on ordinary concrete and fly ash concrete with 30% content,and the effects of stress ratio of axial compression load and carbon dioxide concentration on carbonation depth of two kinds of concrete were analyzed.The results show that the carbonation resistance of ordinary concrete is better than that of fly ash concrete under the action of coaxial compression load and carbon dioxide concentration.Compared with the action group of single carbonation factor,the influence of different sizes of axial compression load and carbonation coupling on the carbonation depth of fly ash concrete is shown as the following law the higher stress ratio promotes the carbonation of fly ash concrete,while the lower stress ratio inhibits it.When the stress ratio increases from 0 to 0.3 to 0.6,the28 d carbonation depth of fly ash concrete decreased by 15% in the former and increased by 25% in the latter,showing a general trend of first decreasing and then increasing.The carbonation depth of concrete is positively correlated with carbonation age and carbon dioxide concentration,and it grows rapidly in the early stage of carbonation.As a matter of fact,the carbonation depth of fly ash concrete in the first7 days under two kinds of CO2concentration can both reach 65% of the rapid carbonation in the first 28 days.
作者
黄毓
逯静洲
王建伟
韩文宇
肖瑛
HUANG Yu;LU Jingzhou;WANG Jianwei;HAN Wenyu;XIAO Ying(School of Civil Engineering,Yantai University,Yantai 264005,China)
出处
《混凝土》
CAS
北大核心
2022年第5期65-68,共4页
Concrete
基金
国家自然科学基金资助项目(51978596)
山东省自然科学基金博士基金项目(ZR2017BEE046)。
关键词
混凝土
粉煤灰
轴压荷载
二氧化碳浓度
碳化
碳化深度
concrete
fly ash
axial compression load
concentrations of carbon dioxide
carbide
carbonation depth
