养护及拌合条件对混凝土密实性的影响  

The Influence of Concrete Curing and Mixing Conditions on the Compactness of Concrete

作　　者：安赛 何小军 范磊 韩云飞 韩嵩 陈金金 李欣浓 段仁武 AN Sai;HE Xiaojun;FAN Lei;HAN Yunfei;HAN Song;CHEN Jinjin;LIN Xinnong;DUAN Renwu(Hebei Normal University of Science&Technology,Qinhuangdao Hebei,066004;Shijiazhuang Institution of Railway Technology,China)

机构地区：[1]河北科技师范学院,河北秦皇岛066004 [2]石家庄铁路职业技术学院

出　　处：《河北科技师范学院学报》2019年第3期67-71,共5页Journal of Hebei Normal University of Science & Technology

基　　金：河北科技师范学院海洋学科专项资助项目(项目编号:2018HY015; 2018HY039)

摘　　要：为研究不同养护及拌合条件对混凝土密实性能的影响,通过实验室混凝土成型养护试验,以测试混凝土试件超声波波速为评价指标,分别研究了C30基准混凝土,在海水拌合及普通自来水拌合条件下,浇筑成型素混凝土和钢筋混凝土等2类试件,分别采用自然养护、自来水养护及海水养护等3种方式,测试其在养护龄期3,7,14,28 d时混凝土试件的超声波波速,以反映混凝土的密实性能。结果表明:海水拌合混凝土在混凝土早期(3~14 d),养护条件对混凝土密实性影响较小;养护后期海水拌合钢筋混凝土及海水养护钢筋混凝土中的Cl^-1及SO4^2-与水泥水化产生的Ca(OH)2反应,致使内部钢筋出现了部分锈蚀,混凝土内部出现了微裂纹,从而使混凝土强度及密实性均降低。其中,海水养护钢筋混凝土28 d波速降低幅度最大,降幅达11%;增加早期湿养护(自来水养护)龄期,可适当增强海水钢筋混凝土的强度和密实性。In order to study the effect of different curing and mixing conditions on concrete compaction performance, tests on pouring, forming and curing of concrete in laboratory, and the ultrasonic velocity of concrete specimens are used as an evaluation index, the C30 benchmark concrete is studied under the conditions of sea water mixing and common tap water mixing. Plain concrete and reinforced concrete are manufactured as two types of specimens. Natural conservation, tap water conservation and sea water conservation are adopted respectively, the ultrasonic velocity of concrete specimens with curing age of 3, 7, 14 and 28 days is measured,which is used to reflect the compactness of concrete. The results show that: in 3~14 d curing of seawater mixed concrete, the effect of curing conditions on the compactness of concrete is small, at the later stage of concrete curing, Cl^-1 and SO4^2- in seawater-mixed reinforced concrete and seawater-cured reinforced concrete react with Ca(OH)2 produced by cement hydration, some corrosion of steel bars in concrete is caused, and micro-cracks appear in concrete, the strength and compactness of concrete are reduced, among them, the wave velocity of reinforced concrete decreases the most after 28 days of sea water curing, and the decline is 11%;Increasing the age of early wet maintenance(tap water maintenance) can properly enhance the strength and compactness of reinforced concrete mixed with seawater.

关 键 词：混凝土 密实性 养护条件 拌合条件 超声波检测 

分 类 号：TU528[建筑科学—建筑技术科学]