摘要
主要研究在混凝土中掺入粉煤灰,对混凝土不同龄期强度的影响。同时将回弹法强度与抗压法强度进行比较。研究粉煤灰对混凝土抗压和回弹强度的影响。通过将混凝土试件标养,测其7、28、60 d的抗压强度,并回弹60 d的强度。试验结果表明:150 mm×150 mm×150 mm试件的抗压强度均较回弹高;7d时混凝土的强度均较低,60 d时,混凝土强度仍有稳步的增长;相同龄期,随着粉煤灰掺量的增加混凝土的氯离子扩散系数随之降低。随着龄期的增长混凝土的氯离子扩散系数随之降低。粉煤灰能够提高混凝土的后期强度同时降低混凝土的氯离子扩散系数,提高混凝土的抗渗性能;混凝土回弹时的强度较抗压时低,主要是因为粉煤灰活性的激发需要碱性条件和湿度条件,碳化和湿度低是造成掺粉煤灰混凝土回弹强度低的主要原因。
The impact of fly ash amount on concrete strength from ages is studied in this paper and then the comparison is conducted between rebound and compressive strength.Study the influence of fly ash on concrete compressive and rebound test strength.Test 7,28 and 60 d concrete compressive strength,which are cured according to national standard as well as 60 d rebound strength.The results show：all the compressive strengths of 150 min×150 min× 150 mm size cubes are higher than the one of rebound;generally, 7 d strength of concrete are low and 60 d strength of concrete is still growing steadily;in the same age,diffusion coefficient of chloride ion decreases with increase of fly ash amount.Along with age up, diffusion coefficient of chloride ion declines.Fly ash could improve concrete long term strength and concrete water resistance ability by lowering chloride ion diffusion coefficient; concrete rebound strength is lower than its compressive strength is mainly due to the alkaline and humidity condition which can activate fly ash activity.Carbonization and humidity are the main reasons to cause low rebound strength of concrete with fly ash additive.
出处
《混凝土》
CAS
CSCD
北大核心
2013年第9期80-82,共3页
Concrete
关键词
粉煤灰
强度
回弹强度
fly-ash
strength
rebound strength
