TSN混凝土复合早强剂的研究及其在抢险工程中的应用

发布时间：2018-04-26 07:18

本文选题：复合早强剂 + 喷射混凝土　；参考：《兰州交通大学》2015年硕士论文

【摘要】：抢险工程具有时效性,这就需要混凝土在较短的时间内达到规定强度。混凝土早期强度高,就能够加快工程施工进度、防止灾害影响扩大或减轻、消除灾害影响。采用快硬性水泥可以达到快速凝结硬化、提高混凝土早期强度的目的,但是造价较高;在普通硅酸盐水泥中加入早强剂,可以在低成本的情况下改善混凝土的工作性,并提高混凝土的早期强度,满足抢险工程需求。本文分析了不同品种早强剂的优缺点,得出混凝土工程中应限制使用氯盐系列早强剂、不宜使用硅酸盐系列早强剂、不建议使用锂盐早强剂的结论;早强剂的发展趋势是复合早强剂取代单组分早强剂。通过水泥浆电阻率确定了复合早强剂的组成成分为三乙醇胺(T)、硫酸钠(S)和亚硝酸钠(N),并命名为TSN复合早强剂。研究三种早强剂组分的早强作用机理,分析出提高硅酸三钙和硅酸二钙的水化反应速度,关键在缩短水泥水化反应诱导期。通过正交设计,简化了数据处理的难度,最终确定了三种组分的配比。经过试验室内检测项目的验证,复合早强剂掺量为水泥质量的1.52%时能减少用水量、缩短水泥凝结硬化时间、提高混凝土的早期强度;与速凝剂、聚羧酸减水剂等有较好的适应性。应用在隧道塌方工程中,混凝土和易性较好,早期强度高。本文的研究成果:(1)复合早强剂的配比为:三乙醇胺(T)1.3%,硫酸钠(S)65.8%,亚硝酸钠(N)32.9%;(2)掺量为1.52%的情况下,能使混凝土的流动性最好,且混凝土强度最高;(3)混凝土早强效果明显,1d龄期强度达到混凝土强度等级的50%,3d龄期强度达到混凝土强度等级的80%;(4)应用在喷射混凝土中,围岩的粘结强度高于其他混凝土与围岩的粘结强度、回弹率低于普通喷射混凝土的回弹率。
[Abstract]:Emergency engineering has timeliness, which requires concrete to reach the specified strength in a short time. If the concrete has high early strength, it can accelerate the construction progress, prevent the disaster influence from expanding or reducing, and eliminate the disaster impact. The use of fast hardening cement can achieve the purpose of rapid solidification and hardening and increase the early strength of concrete, but the cost is high; adding early strength agent to ordinary Portland cement can improve the workability of concrete at low cost. And improve the early strength of concrete to meet the needs of emergency engineering. This paper analyzes the advantages and disadvantages of different kinds of early strength agents and draws the conclusion that the use of chlorine salt series early strength agents should be restricted and silicate series early strength agents should not be used and lithium early strength agents should not be used in concrete engineering. The development trend of early strength agent is to replace one component early strength agent with composite early strength agent. Through the resistivity of cement slurry, the composition of the composite early strength agent was determined to be triethanolamine, sodium sulfate and sodium nitrite, and named as TSN compound early strength agent. The mechanism of early strength of three kinds of early strength agents was studied. The key to improve the hydration rate of tricalcium silicate and dicalcium silicate was to shorten the induction period of cement hydration reaction. The difficulty of data processing was simplified by orthogonal design, and the ratio of three components was determined. After testing in laboratory, it can reduce water consumption, shorten setting time and improve early strength of concrete when the content of composite early strength agent is 1.522wt% of cement quality. Polycarboxylic acid superplasticizer has good adaptability. In tunnel collapse engineering, the concrete is easy to use and the early strength is high. The results of this paper are as follows: the ratio of triethanolamine, sodium sulfate, sodium nitrite and sodium nitrite is 1.52%, and the fluidity of concrete is best when the ratio of triethanolamine, sodium sulfate and sodium nitrite is 1.52%. And the concrete strength is the highest, and the effect of early strength of concrete is obvious. When the 1d age strength reaches the concrete strength grade, the concrete strength reaches the concrete strength grade 80 / 4) and is used in the shotcrete. The bond strength of surrounding rock is higher than that of other concrete and the rebound rate is lower than that of ordinary shotcrete.
【学位授予单位】：兰州交通大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TU528

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