泡沫轻质混凝土单轴循环加卸载试验研究

为研究循环加卸载对泡沫轻质混凝土力学性能的影响,采用微机控制电子万能试验机对湿密度为700 kg/m~3的泡沫轻质混凝土试样开展3组方案的循环加卸载试验,重点研究循环加卸载对其应力-应变曲线、峰值强度、弹性模量的影响。研究结果表明:随着循环加卸载的进行,应力-应变曲线出现不断迁移的现象,且对于3种试验方案,第一次循环加卸载引起的迁移值最大,而后,采用加卸载方案1、方案2,迁移值随着加卸载次数增加而减小,采用加卸载方案3,迁移值随着加卸载次数的增加先减小后增加;对于3种加卸载方案,峰值强度随着加载幅值的增加而增大,且随着循环加卸载次数的增加而增大;对于3种加卸载方案,第1次加卸载对弹性模量影响最大,而后,对于试验方案1、方案2,弹性模量随着循环加卸载次数的增加而增加,而对于试验方案3,弹性模量随着循环加卸载次数的增加而减小。

Experiment of Foamed Lightweight Concrete under Uniaxial Cyclic Loading and Unloading Conditions

In this paper,computer-controlled electronic universal testing machine is used to study the effect of cyclic loading and unloading on foamed lightweight concrete mechanical properties. Loading and unloading experiments are performed on the foamed lightweight concrete with the wet density of 700 kg /m3 to study the influence of loading and unloading on such mechanical properties of foamed lightweight concrete as stress-strain behavior,peak strength and elastic modulus. The results show that the stress-strain curves of the foamed lightweight concrete continue migration with the progresses of cyclic loading and unloading. For the three experiment programs,the migration values of the first loading and unloading are the largest. After that,the migration values decrease with the increase of the number of loading and unloading for experiment program1 and 2. But for program3,the migration values first decrease and then increase with the increase of the number of loading and unloading. For the three experiment programs,the peak strength increases with the increase of load amplitude and also increases with the increase of the number of loading and unloading. The first loading and unloading experiment has the biggest impact on the elastic modulus for the three experiment programs. After that,the elastic modulus increases for the experiment program1,2 and decreases for the experiment program3 with the increase of the number of loading and unloading.