摘要
采用机械压砖机制作生土砖试块,通过抗压和抗折试验研究其力学性能。采集西北地区黄土,分别掺入质量比为0.12的水泥和质量比为0.15的砂,制作生土砖试块,外形尺寸为240 mm×115 mm×90 mm,养护至干燥状态后进行抗压、抗折试验。研究了20个不同掺料试块的试验破坏过程、极限荷载、破坏机理和变形能力,结果表明,掺水泥和掺砂的机制生土砖分别达到了混凝土砌块MU7.5和MU5的强度指标,说明通过合适的改性掺料和机械压制,生土砖可作为承重砌块使用。根据试验中测得的两类机制生土砖受压的应力-应变全曲线,提出了机制生土砖受压的应力-应变本构关系;通过对比不同制作方法试块在相同配比、养护、加载条件下的抗压试验,研究了分别采用机械压制和落锤击实的制作生土砖方法对抗压强度和离散性的影响。试验和研究结果为生土改性材料和新型生土结构的力学性能研究提供参考。
The raw-soil brick was moulded in the brick press and the mechanical properties were investigated by compressive and flexural tests. The loess of northwest China was mixed with cement by a mass ratio of 0. 12 and sand by a mass ratio of 0. 15,respectively. The mixtures were pressed in KP1 type by brick machine and allowed to dry. A total number of 20 specimens were tested to study the compressive strength,flexural strength,failure process and deformability. It shows that the compressive strength of machine-pressed brick mixed with cement is equal to the concrete block MU7. 5,while the brick mixed with sand is equal to MU5,indicating that the raw-soil material can be used as load-bearing block after machine-pressing and material modification. The constitutive equation of raw-soil matrix bricks was established on the basis of the test data. The influence of different manufacturing methods on the compressive strength and discreteness was analyzed by the comparison of tests of raw-soil specimens made by different production methods with the same proportion,curing condition and loading conditions. The results provide a theoretical basis for raw-soil structure research and the reference to specimen fabrication and strength calculation of raw-soil machine-pressed bricks.
出处
《建筑结构学报》
EI
CAS
CSCD
北大核心
2016年第S1期434-439,共6页
Journal of Building Structures
基金
高等学校博士学科点专项科研基金(20130205110012)
关键词
机制砖改性
静力试验
抗压强度
抗折强度
machine-pressed brick modification
static test
compressive strength
bending strength
