摘要
为了研究外掺Mg O微膨胀混凝土在不同应变速率条件下的力学性能,进行了不同Mg O掺量以及不同Mg O活性混凝土在不同应变速率的单轴压缩试验,并对微膨胀混凝土的抗压力学基本参数以及相应的破坏机理进行了深入分析。研究结果表明：随着Mg O掺量的升高混凝土的极限抗压强度呈现出先增加后减小的规律,Mg O掺量控制在6%～9%之间能有效的限制混凝土裂缝的扩展;随着Mg O活性的不断提高混凝土极限抗压强度先增加后趋于平缓,Mg O活性在100s时混凝土极限抗压强度达到最大值;随着应变速率的升高,不同Mg O掺量混凝土的极限抗压强度出现了一定的增长,但是这种增长趋势表现出了一定的离散性;Mg O活性较低时,混凝土的内部孔隙较少,混凝土的破坏相对较高活性的有所延迟。随着掺入的Mg O活性增大,Mg O的颗粒相应加大,在低应变速率下,混凝土的延迟破坏表现不明显。
In order to study the mechanical properties of micro- expansion concrete mixed with Mg O under different strain rates,uni- axial compression test are carried on about different Mg O contents and different Mg O activity. Basic mechanics parameters and corresponding damage mechanism of micro-expansion concrete are analyzed. The results show that the ultimate pressure resistance of concrete appears firstly increase then decrease with increase of Mg O content. When Mg O content is controlled between 6% with9%,it can effectively limit the expansion of concrete crack; the ultimate pressure resistance of concrete appears first increase then level off with Mg O activity continuing to increase,concrete ultimate compressive strength reaches a maximum when Mg O activity at100s; the ultimate pressure resistance of concrete appears a certain amount of growth with increase of strain rate,but this growth trend shows some of discrete; concrete damage is delayed relative to higher activity as less internal pore under lower Mg O activity.Mg O particles size increase corresponding with the increase of Mg O activity,and the procrastination damage is not obvious at low strain rate.
出处
《湖北工业职业技术学院学报》
2015年第6期91-94,共4页
Journal of Hubei Industrial Polytechnic
