摘要
通过试验对比研究了普通强制搅拌、振动搅拌以及掺入引气剂对新拌混凝土匀质性、含气量以及硬化混凝土抗压强度、孔结构的影响。结果表明:随着引气剂的掺入以及引气剂掺量的增加,振动搅拌和普通强制搅拌混凝土的匀质性变化不大,但混凝土含气量随之增加,抗压强度随之降低,并且与普通强制搅拌相比,振动搅拌混凝土的含气量更大,抗压强度更高;振动搅拌和掺入引气剂都能提高硬化混凝土的孔隙率,但振动搅拌主要增多的是100nm以下的小孔,不仅提高了引气效果,而且也因为使孔隙细化,改善了混凝土抗压强度;当需要的混凝土含气量(体积分数)为3%时,采用振动搅拌即可获得所需的引气效果,而当需要的含气量更大时,建议采用振动搅拌同时掺入引气剂。
The effects of common forced mixing, vibrating mixing and mixing with air entraining agent on homogeneity and air content of fresh concrete, compressive strength and pore structure of hardened concrete were tested and compared. The results show that the homogeneity of concrete by vibrating mixing and common forced mixing have little change with the addition and increasing of air entraining agent, but the air content of the concrete increases and the compressive strength decreases. The concrete made by vibrating mixing has higher air content and compressive strength than that made by common forced mixing. Vibrating mixing and common forced mixing with air entraining agent can improve the porosity of the hardened concrete, but the harmless pores with diameters less than 100 nm in the concrete by vibrating mixing increase significantly and the harmful large pores decrease, so vibrating mixing can improve the air entraining effect, and increase concrete compressive strength. When the air content （volume fraction） of concrete is required to be 3%, the required effect of air entraining can be obtained only by vibrating mixing when the air content is required to be higher than 3 %, vibrating mixing with air entraining agent is recommended.
出处
《建筑科学与工程学报》
CAS
北大核心
2013年第1期32-37,共6页
Journal of Architecture and Civil Engineering
基金
国家自然科学基金项目(50678026)
中央高校基本科研业务费专项资金项目(CHD2011JC093)
关键词
混凝土
含气量
抗压强度
孔结构
引气剂
振动搅拌
普通强制搅拌
concrete
air content
compressive strength
pore structure
air entraining agent
vi-brating mixing
common forced mixing
