矿渣、粉煤灰掺量对混凝土收缩、开裂性能的研究  

Study on Concrete Shrinkage and Cracking Properties with Different Slag or Fly-Ash Proportions

作　　者：乔艳静[1] 费治华[1] 田倩[1] 刘加平[1] 

机构地区：[1]江苏博特新材料有限公司,南京210008

出　　处：《长江科学院院报》2008年第4期90-92,96,共4页Journal of Changjiang River Scientific Research Institute

摘　　要：收缩、开裂是影响现代混凝土耐久性的主要因素,为评价掺合料对混凝土收缩、开裂的影响,通过圆环开裂试验、收缩试验来评定矿物掺和料对混凝土收缩开裂的性能。圆环开裂试验主要表征混凝土试件在约束条件下抵抗干燥收缩应力的能力,收缩试验则表征试件的体积变形,收缩是开裂的原因,也是影响开裂的最重要因素。结果表明矿渣掺量在一定范围内时可抑制混凝土的开裂,混凝土的自收缩随矿渣掺量的增大而增大,干缩随矿渣掺量的增大而减小。粉煤灰可有效抑制混凝土的开裂,随掺量的增大抑制作用越显著;粉煤灰掺量越大对自收缩的抑制作用越明显,混凝土的干缩略有增大。总的来看,粉煤灰较矿渣可更好地抑制混凝土的收缩与开裂。Shrinkage and cracking are the primary factors influencing the durability of modern concrete. In order to evaluate the effect of the mineral admixtures on the concrete shrinkage and cracking properities, a lot of tests were conducted by the ring test method and shrinkage experiment. The ring test method mainly reflects the resistance to drying shrinkage stress under the restraining conditions. The shrinkage test mainly reflects the voltune deformation. The experimental results show as follows： Slag could inhibit the cracking of concrete within the range of certain proportion. With the increase of slag proportion the self-shrinking of concrete increases, but the drying shrinkage of concrete decreases. Fly-ash could effectively inhibit the cracking of concrete, with the increase of fly-ash proportion the concrete cracking could be effectively inhibited. With the increase of fly-ash proportion the self-shrinking of concrete decreases, but the drying shrinkage of concrete would increase. As a whole, the fly-ash could effectively control the concrete shrinkage and cracking.

关 键 词：粉煤灰 矿渣微粉 初始开裂时间 自收缩 裂缝宽度 干缩 

分 类 号：TU528[建筑科学—建筑技术科学]