抗裂型外加剂对粉煤灰混凝土抗压强度的影响

考虑抗裂型外加剂类型及其掺量的影响，开展了粉煤灰混凝土在养护与硫酸盐腐蚀条件两种情况下抗压强度的试验研究。试验结果表明：不同粉煤灰掺量下UEA型膨胀剂对混凝土力学性能的影响规律一致，HME-V高效抗裂剂的影响规律不同。养护龄期内，掺加UEA或HME-V与30%粉煤灰的混凝土抗压强度值均在90 d后处于稳定，掺量均以5%为最佳强度掺量，硫酸盐腐蚀后以5%外加剂掺量的试件损失最低。5%和8%两种掺量下，随着粉煤灰掺量的提高（10%~30%），掺加两种抗裂外加剂的试件28 d抗压强度均降低。养护的30%粉煤灰掺量的UEA试件强度总大于HME-V试件。硫酸盐腐蚀后掺加HME-V的试件强度大于UEA试件强度。HME-V外加剂较UEA能更好地延缓硫酸盐腐蚀造成的力学性能损失。

The Influence of Crack Resistant Admixture on the Compressive Strength of Fly Ash Concrete

Considering the influence of the type and content of anti-cracking admixture, the evolution of compressive strength of fly ash concrete under the conditions of curing and sulfate corrosion was studied. The test results show that the effect of UEA expansion agent is the same under different fly ash content, and the effect of HME-V high-efficiency anti-cracking agent is different. During the curing period, the compressive strength value of 30% fly ash mixed with UEA or HME-V is stable after 90 days. The best strength content is 5% and the loss of the specimen with 5% content is the lowest after sulfate corrosion. With the increase of fly ash content (10%~30%), the compressive strength at 28d of the two kinds of anti-cracking admixtures decreases. The strength of UEA specimens cured with 30% fly ash content is higher than that of HME-V specimens. After sulfate corrosion, the strength of HME-V specimens is higher than that of UEA. HME-V admixture can better delay the loss of mechanical properties caused by sulfate corrosion than UEA.