摘要
为了研究粉煤灰对大含气量混凝土抗冻性的影响,制备了粉煤灰掺量为25%、30%、35%、40%、50%的混凝土试件,采用快冻法进行冻融循环试验研究。结果表明:一定量的粉煤灰会对试件的早期抗压强度造成影响,整体上大含气量混凝土的强度随着粉煤灰掺量的增加而降低;混凝土试件在冻融试验初期质量损失不明显,随着试验的进行,质量损失率整体呈增大趋势;对比质量损失率和相对动弹性模量两个评价指标,引气剂的添加对混凝土的内部结构有明显改善作用,冻融循环破坏主要是试件外表面的破坏;在含气量为6%条件下,粉煤灰的最适宜掺量为25%,结合工程实际需要可提升至30%,以节约施工成本。
In order to study the effects of amount of fly ash on the high air content concrete, it studied the concrete specimens5 with mixing amount of fly ash 25%,30%,35%,40% and 50%, by quick thawing and freezing method and after freeze-thaw cycle 200 times. The results show that the early strength of the specimen will be affected by a certain amount of fly ash, the strength of high air content concrete will be decreased with the increase of amount of fly ash; at the beginning of the test, the mass loss of the specimen does not decrease obviously, with the deepening of the experiment, the mass loss performance is significantly increased. Comparing the mass loss rate with the relatively dynam-ic elastic, the air-entrained agent added, the integrity of concrete is improved obviously, freeze-thaw damage mostly effect on outer surface by pore structure evolution test; under the conditions of 6% gas content, its optimal amount of fly ash is 25% of high air content concrete and the amount of fly ash can be increased to 30% in practical engineering for saving construction cost.
出处
《人民黄河》
CAS
北大核心
2017年第10期133-136,共4页
Yellow River
基金
国家自然科学基金资助项目(51569021)
高等学校博士学科点专项科研基金资助项目(20121515110002)
内蒙古自治区科技计划应用与研究开发项目(20130425)
关键词
含气量
粉煤灰
抗冻性
孔结构分析
air content
fly ash
frost resistance
pore structure evolution
