生土基砌体抗压强度测量标准试件的试验研究

Experimental study on standard specimen for measuring compressive strength of earth block masonry

通过对湿制土坯砌体和干打土坯砌体进行单轴抗压试验,分析试件高厚比和加载面找平方式对生土基砌体抗压性能的影响。研究结果表明:生土基砌体抗压性能对于试件高厚比的变化更为敏感,我国“砌体基本力学性能试验方法标准”中关于标准砌体抗压试件高厚比应控制在3~5的规定不能适用于生土基砌体;当试件高厚比为3~4时,2类生土基砌体破坏形态统一,能真实反映砌体构件受压状态,且试验数据稳定性较好,建议生土基砌体强度标准试件的高度应按高厚比为3~4确定;采用快硬石膏自流平对试件加载面进行找平可保证2类生土基砌体顶面与加载板紧密接触,且所测得砌体抗压强度离散性较小,建议生土基砌体强度标准试件顶部找平方式选用快硬石膏自流平找平方式。

The molded adobe masonry prisms and compacted adobe masonry prisms were prepared and tested in unconfined compression test to investigate the influences of the height-to-thickness ratio of specimen and capping on the compressive performance of earth masonry prisms.The results show that the compressive performance of earth masonry prisms are sensitive to the change of height-to-thickness ratio of specimen and the stipulation on the height-to-thickness ratio of compressive specimens in"standard for test methods of basic mechanical properties of masonry"does not apply to earth masonry prisms.When the height-to-thickness ratio of specimen is 3−4,the failure modes of the two kinds of earth masonry prisms are unified,which can truly reflect the compressive state of masonry members,and the test data are stable.It is suggested that the height of standard specimens for measuring compressive strength of earth masonry prism should be determined according to the height-to-thickness ratio of 3−4.Leveling the loading surface of the specimen with fast anhydrite can ensure that the top surface of the two kinds of earth masonry prism are in close contact with the loading plate,and the discreteness of measured compressive strengths are small.It is suggested that the leveling method of fast anhydrite self-leveling be used for leveling the top of standard specimens.