摘要
振动搅拌是高效节能生产混凝土的一种新技术,为在常用的C20、C30、C40混凝土生产中使用该技术,进行了振动搅拌对不同配合比混凝土性能影响的试验研究。在投料顺序、搅拌时间与速度、振动强度相同的条件下,进行不同配合比混凝土的振动与不振动搅拌的比对试验,得到的结果是,振动搅拌使得新拌混凝土的坍落度有所降低,C20混凝土的坍落度降低了23.8%,C30降低了15.3%,C40降低了25%;同时,新拌混凝土的保水性与粘聚性良好;传统强制搅拌的混凝土含气量在2.5%左右,振动搅拌将含气量的数值提高到了3%左右,振动搅拌过程对混凝土的引气效果相当明显;振动搅拌的不同配合比混凝土强度普遍高于传统强制搅拌的10%以上;随着混凝土配合比的升级,振动搅拌对混凝土强度提高的幅度在减弱;同时振动搅拌混凝土前期强度的增长速率较快,后期放缓;而不振动的传统强制搅拌的混凝土,前期强度增长平缓,后期有所加快;振动搅拌混凝土平均强度的离差系数比传统强制搅拌的要小30%以上。研究发现,与不振动强制搅拌方式相比,振动搅拌可以明显提高不同配合比混凝土的强度与均质性,引气效果明显,但新拌混凝土的坍落度有所降低,这为振动搅拌技术在商品混凝土生产中的应用提供了依据。
Vibratory mixing is a new efficient and energy-saving technology of mixing concrete. In order to apply this technology to the production of C20, C30 and C40 concretes, an experimental re-search of effects of vibratory mixing on the performance of concrete with different mixing proportions was conducted. Comparative experiments between vibratory mixing and normal mixing of concrete with different mixing proportions were conducted under the same feeding sequence, mixing time, mixing rotation and vibration intensity. The results showed that vibratory mixing made slumps of fresh concrete decrease. Concretely, slumps of C20, C30 and C40 concrete decreased by 23. 8%, 15. 3% and 25% respectively. Besides, water holding capacity and cohesiveness of fresh concrete were good. Air content of the concrete produced by traditional forced mixing is about 2. 5%, but vi-bratory mixing raised the air content to 3% around, which indicated that vibratory mixing process＆amp;nbsp;had obvious air-entraining effect on concrete. Strengths of concrete mixed by vibratory mixing with different mixing proportions were generally 10% higher than that of concrete mixed with traditional forced mixing. As the mixing proportions went up, the improving effect of vibratory mixing on the strength of concrete was weakened. Besides, the early-stage strength of concrete with vibratory mix-ing increased rapidly and the late-stage strength increased slowly. Instead, the early-stage strength of concrete through traditional forced mixing without vibration increased slowly and the late-stage strength increased rapidly. And the coefficient of dispersion of average strength of the concrete mixed with vibration was more than 30% lower than that of the concrete mixed with traditional forced mix-ing. The research indicated that vibratory mixing could obviously improve the strength, uniformity and air content as well as decrease the slumps of the concrete compared with normal forced mixing, which provided base for the use of vibratory mixing in commercial concre
出处
《广西大学学报（自然科学版）》
CAS
北大核心
2015年第3期636-642,共7页
Journal of Guangxi University（Natural Science Edition）
基金
国家自然科学基金资助项目(50678026)
陕西省重大科技创新专项资金计划项目(2008ZKC01-16)
关键词
混凝土
振动搅拌
强制搅拌
配合比
工作性
含气量
强度
concrete
vibratory mixing
forced mixing
mixing proportions
performance
air con-tent
strength
