摘要
混凝土暴露在高温下,其组成材料经历不同的体积变化与损伤时就会产生裂纹使得耐久性能与力学性能降低,胶凝材料与粗骨料在其中起着重要作用。在此对比掺入10%硅灰和采用碎石、页岩陶粒对混凝土高温后强度损失的影响与形貌变化。高温后持续荷载下的徐变至关重要,所以还对比了不同骨料类型与荷载对混凝土徐变的影响。结果表明:400℃后混凝土强度明显下降,硅灰的掺入增大了强度降幅。轻骨料混凝土的残余抗压强度在高温下远高于常规混凝土,且内部由于热膨胀应力的缓解出现了较少的裂缝。当施加恒载时,500℃以下轻骨料混凝土变形大,超过500℃,普通混凝土变形高于轻骨料混凝土。
When concrete is exposed to high temperature,cracks will occur when its constituent materials undergo different volume changes and damage,resulting in the decrease of durability and mechanical properties,in which cementitious materials and coarse aggregates play an important role.The effects and morphology changes of strength loss of concrete after high temperature by adding 10%silica fume and using crushed stone and shale ceramsite are compared here.Creep under continuous load after high temperature is very important,so the effects of different aggregate types and loads on concrete creep are compared.The results show that the strength of concrete decreases obviously after 400 C,and the strength decrease increases with the addition of silica fume.The residual compressive strength of lightweight aggregate concrete is much higher than that of conventional concrete at high temperature,and there are fewer cracks due to the relief of thermal expansion stress.When the dead load is applied,the deformation of lightweight aggregate concrete below 500 C is large,and the deformation of ordinary concrete is higher than that of lightweight aggregate concrete above 5o0 C.
作者
黄正峰
欧忠文
罗伟
王飞
王廷福
HUANG Zhengfeng;OU Zhongwen;LUO Wei;WANG Fei;WANG Tingfu(Department of Military Facilities,Logisticse College of PLA,Chongqing 401311,China)
出处
《混凝土》
CAS
北大核心
2024年第1期107-109,115,共4页
Concrete
基金
军队后勤科研计划项目(BLJ17J008)
军委后保部科研项目(CLJ19J020)
国家自然科学基金(11702324)。
关键词
轻骨料
硅灰
徐变
高温
强度
lightweight aggregate
silica fume
creep
high temperature
strength
