轴拉荷载作用下粉煤灰混凝土碳化性能研究

Study on the carbonation properties of the fly ash concrete under the axial tension load

研究通过自行研制的长期轴拉持载装置,对不同掺量的粉煤灰混凝土进行短期及长期轴拉荷载下的碳化试验,探讨不同荷载水平的短期加载及长期持载形式对混凝土碳化的影响,进一步分析拉、压荷载对混凝土碳化性能影响的区别。结果表明:在各碳化龄期,不同掺量粉煤灰混凝土碳化深度均随荷载水平的增加而增大;长期持载较短期加载对粉煤灰混凝土的抗碳化性能更为不利;粉煤灰掺量低于30%时,轴拉荷载下的碳化深度大于轴压荷载下的碳化深度,当粉煤灰掺量达到40%,应力水平超过20%时,轴压荷载较轴拉荷载对混凝土的抗碳化性能更为不利。

In this paper,by using the self-developed long-term axial tension loading device,the carbonization test with different dosages of fly ash concrete was carried out,and the effect of different axial tension loads on the carbonation depth of fly ash concrete was analyzed in two cases of short-term load and long-term load.Meanwhile,the effect of the tension and compression load on the carbonization depth of the concrete was further analyzed.The results show that with the increase of the long-term load,the depth of carbonization of the four contents fly ash concrete increases continuously in each carbonization age;the long-term load is more unfavorable than short-term load to the concrete carbonation resistance.Meanwhile,when the fly ash content is under 30%,the carbonization depth under the axial tension load is greater than the carbonization depth under the axial compression load;and when the fly ash content is 40%,at the same time the stress level exceeds 20%,the axial compression load is more unfavorable than axial tension load to the concrete carbonation resistance.