摘要
针对磺化碱木质素(SWSL)引气性过强造成混凝土抗压强度下降的问题,通过复配消泡剂二甲基硅油、表面活性剂十二烷基硫酸钠(K12)、脂肪醇聚氧乙烯醚(AEO)进行改性以改善其引气性,得到改性磺化碱木质素(GSL),系统研究了其物化性能及作为混凝土减水剂应用的性能。结果表明,GSL具有较强表面活性,泡沫细腻均匀,最大泡径仅0.5mm。掺加GSL的水泥颗粒表面Zeta电位比SWSL和木质素磺酸钙CLS的高,达到-33mV。与SWSL和CLS比较,GSL能在低掺量下使新拌砂浆具有更高减水率和引气性,且砂浆150min流动度损失率仅为3.8%。GSL能明显改善硬化砂浆孔隙结构,孔径小于0.02mm的小孔体积分数高达81.5%。掺量w(GSL)=0.25%时,混凝土减水率达13.6%,3d和7d抗压强度比分别为164%和163%,均高于CLS,达到高效减水剂标准。
Sulfonated wheat straw lignin （SWSL） causes the decrease of concrete strength due to the problem of the strong air entraining property. In order to improve the air entraning property, modified sulfonation wheat straw lignin （GSL） is obtained through combining with defoaming agent, dimethyl silicone oil,sulfactant dodecyl sodium sulfate（K12） and fatty alcohol-polyoxyethylene ether AEO. The performances of GSL are investigated. The result shows that GSL has a high surface activity. The foaming performance of GSL is small and homogeneous, and the biggest bubble diameter is only 0.5 mm. The surface Zeta potential of cement particles blended with GSL is higher than that of SWSL and CLS, which reaches -33 mV. In comparison with SWSL and CSL, GSL has higher water-reducing ratio and stronger air entraning property under low dosage. The loss of fluidity in mortar blended with GSL is only 3.8% in 150 min. GSL can improve the structure of pores obviously;the volume content of pore with diameter smaller than 0.02 mm reaches 81.5 %. When w （GSL） = 0. 25 % , the water-reducing ratio of GSL reaches 13.6% ; the 3 d and 7 d compressive strength ratio of concrete are 164% and 163% ,which reach the standard of the high performance in water reducer.
出处
《精细化工》
EI
CAS
CSCD
北大核心
2009年第9期857-862,共6页
Fine Chemicals
基金
国家高技术研究发展计划(2007AA06Z322)
国家自然科学基金(20876064)
广东省科技计划资助项目(2006A37002001)~~
关键词
碱木质素
磺化
混凝土
高效减水剂
表面活性剂
alkaline lignin
sulfonation
concrete
high performance water reducer
surfactants
