【作者】 魏斌；

【导师】 胡琼； 武鹤；

【作者基本信息】 哈尔滨工业大学 ， 建筑与土木工程（专业学位）， 2019， 硕士

【摘要】 碱激发混凝土相比普通混凝土,具有良好的力学及耐久性能,但其收缩远大于普通混凝土。与此同时,碱激发混凝土存在初凝时间过快的问题,严重制约了碱激发混凝土的工程实际应用。我国每年产生的地沟油数量巨大,对环境造成极大污染,并有很大部分回流餐桌,对人体健康产生巨大危害,前期有学者将地沟油添加于水泥基混凝土中,研究其收缩及其他性能。本课题基于此,将废弃食用油引入碱激发混凝土,以解决碱激发混凝土收缩大和凝结过快等两大问题,变废为宝,合理利用了废弃食用油,同时解决碱激发混凝土实际工程应用问题。本文以地沟油为原材料,制备油脂减缩剂代替市场膨胀剂和减缩剂,加入碱激发混凝土以研究其对碱激发混凝土收缩及耐久性能的影响。同时通过砂浆试验探究油脂减缩可行性,净浆试验探究微观分析,具体工作如下:(1)碱激发砂浆试验分为12组,每组3块,共36块。通过碱激发矿粉砂浆试验探究油脂是否可以降低碱激发胶凝材料收缩性能。同时改变碱激发矿粉砂浆水灰比(水灰比取0.3与0.5)以确定油脂减缩剂对碱激发矿粉砂浆收缩性能的影响。试验结果发现油脂减缩剂对碱激发矿粉砂浆有减缩效果。(2)碱激发混凝土试验分为12组,共计396块。混凝土试验通过改变油脂减缩剂种类(乳化、非乳化、食用油、地沟油)、添加剂量(2%、4%),以无添加、添加UEA膨胀剂、日本Hibidan B减缩剂作为对比展开研究。对碱激发混凝土在不同减缩剂作用下自收缩及干燥收缩的变化,抗压、抗折、抗缩、抗碳化等其他物理力学性能与油脂减缩剂之间的关系进行相应研究。(3)通过压汞试验、扫描电镜、XRD对碱激发矿粉净浆试块进行微观结构、成分分析,从微观角度探究碱激发混凝土收缩性能改变的原因。更多还原

【Abstract】 Alkali-activated slag concrete has good physical properties compared with conventional concrete.However,the shrinkage performance is larger than conventional concrete.The initial setting time of alkali-activated concrete is shorter,which has seriously restricted the construction site application of alkali-activated slag concrete.Waste cooking oil,commonly known as hogwash oil,has been produced in a huge amount each year in China,which has caused a great harm to environment.At the same time,a large part of the hogwash oil is returned to the table,which has great harm to human health.Some scholars applied it to conventional concrete.In this paper,the topic is based on that by applying the waste cooking oil,which act as a shrinkage reduction agent into the alkali activated slag concrete,and is considered to overcome the two main problems of alkali-activated slag concrete.One is making rational use of waste cooking oil,the other one is reusing waste into and reducing the practical project cost.Instead of using the commercial available expansion agent or the shrinkage reducing agent,this experiment use the waste cooking oil as the shrinkage reducing agent.The alkali-activated slag concrete experiment was conducted to study the effect of the waste cooking oil on the shrinkage and durability performances of the alkali-activated slag concrete.At the same time,the alkali-activated slag paste test was also conducted to explore the micro-structure of the slurry experiment.The detail of the study was illustrated as followed.(1)The alkali-activated slag mortar experiment was divided into 12 groups.Each group owns 3 pieces.The total number of the specimens is 36.The alkali-activated slag mortar experiment was conducted to investigate whether the waste cooking oil can reduce the shrinkage of the alkali-activated cementitious material.At the same time,the water-cement ratio of the alkali-excited of mortar was changed(the water to cement ratio was 0.3 and 0.5)to determine the effect of the oil shrinkage reducing agent on the shrinkage performance of the alkali-activated slag mortar.The experimental results show that the waste cooking oil has a shrinking reducing effect on the alkali-activated slag mortar.(2)The alkali-activated slag concrete experiment was divided into 12 groups with a total of 396 specimens.The concrete experiment was carried out by changing the types of the oil(emulsified,non-emulsified,edible oil,waste oil)and dosage(2%,4%).The relative between autogenous shrinkage and drying shrinkage ofalkali-activated concrete by applying different shrinkage-reducing agents was studied.The influence of different shrinkage reducing agents on mechanical and durability properties were also studied.(3)Microstructure analysis of alkali-activated slag paste by mercury intrusion experiment and SEM was also studied.The influence mechanism of shrinkage reducing properties were explained by the microstructure analysis.更多还原