外加剂对机制砂混凝土表面气泡参数影响试验研究  

Experimental study on influence of admixture on surface bubble parameters of manufactured sand concrete

作　　者：温金保[1,2,3] 樊金光 唐修生 杜志芹[1,2,3] 刘兴荣 夏强[1,2,3] 季海 WEN Jinbao;FAN Jinguang;TANG Xiusheng;DU Zhiqin;LIU Xingrong;XIA Qiang;JI Hai(Nanjing Hydraulic Research Institute,Nanjing 210029,China;Nanjing R&D Hi-Tech Co.Ltd.,Nanjing 210024,China;Research Center on New Materials in Hydraulic Structures of Ministry of Water Resources,Nanjing 210024,China;Ningbo Hangtong Prefabricated Components Engineering Co.Ltd.,Ningbo 315207,China)

机构地区：[1]南京水利科学研究院,江苏南京210029 [2]南京瑞迪高新技术有限公司,江苏南京210024 [3]水利部水工新材料工程技术研究中心,江苏南京210024 [4]宁波航通预制构件工程有限公司,浙江宁波315207

出　　处：《新型建筑材料》2021年第11期129-132,共4页New Building Materials

基　　金：中央级公益性科研院所基本科研业务基金(Y420010)。

摘　　要：硬化机制砂混凝土表面易出现大量气孔结构,严重影响混凝土外观质量及其耐久性,开展了外加剂对机制砂混凝土表面气泡参数的影响规律研究。结果表明:采用的4种外加剂掺量对混凝土表面气泡参数的影响均较大;掺保坍型聚羧酸系减水剂的混凝土表面气泡面积百分率、直径D≤1 mm与D>1 mm气泡数量均明显高于减水型聚羧酸系减水剂;引气剂的掺入明显增大了混凝土表面气泡面积百分率、最大孔径、直径D≤1 mm与D>1 mm气泡数量;消泡剂的掺入则相反,明显降低了混凝土表面气泡面积百分率、最大孔径、直径D≤1 mm与D>1 mm气泡数量,可极大改善混凝土表面气泡外观质量;含气量的提高将导致气泡面积百分率与直径D>1 mm气泡数量增大的概率上升,不利于混凝土外观质量的改善。A large number of pores were easy to produce on the surface of hardened manufactured sand concrete.It seriously affected the appearance quality and durability of concrete.Taking four kinds of admixtures as the research object,the influence of admixtures on the surface bubble parameters of manufactured sand concrete was studied.The results show that these admixtures have great influence on the surface bubble parameters of concrete.The percentage of bubble area and the number of bubbles with diameter D≤1 mm and D>1 mm of hardened concrete surface with slump retention type polycarboxylate superplasticizer are significantly higher than those of water reducing type polycarboxylate superplasticizer.The addition of air entraining agent significantly increases the percentage of bubble area,the maximum pore size,the number of bubbles with diameter D≤1 mm and D>1 mm on the surface of concrete.On the contrary,the addition of defoamer significantly reduces the percentage of bubble area,the maximum pore size,the number of bubbles with diameter D≤1 mm and D>1 mm.It can greatly improve the appearance quality of concrete surface bubbles.The increase of air content will lead to increasing of the probability for the increase of bubble area percentage and bubble number with diameter D>1 mm.It is disadvantageous to the improvement of concrete appearance quality.

关 键 词：机制砂混凝土 表面气泡 气泡面积百分率 含气量 

分 类 号：TU528[建筑科学—建筑技术科学]