不同胶凝材料体系水工混凝土的力学与变形性能研究

发布时间：2018-02-24 02:32

本文关键词： 水工混凝土胶凝材料体系水胶比准绝热温升自生体积变形干燥收缩　出处：《浙江工业大学》2014年硕士论文　论文类型：学位论文

【摘要】：在实际的混凝土工程应用中,由于混凝土自身的极限拉伸强度不足以抵抗水化热引起的温度应力及收缩引起的收缩应力,导致混凝土裂缝的产生与开展,对结构产生破坏性危害。对于水工混凝土之类的大体积混凝土的开裂问题一直更是备受关注。解决大体积混凝土的开裂问题,需对混凝土力学性能,水化热机理及其特性,收缩变形性能进行深入研究,而作为混凝土最重要组成材料的胶凝材料则是研究的基础。本文即是以水泥种类、粉煤灰、水胶比等为实验参数,实验研究了水工混凝土胶凝体系的抗压、抗折强度,水工混凝土的抗压强度、抗拉强度,以及两者的准绝热温升特性、自生体积变形与干缩变形。在本文研究范围内可得出以下结果或结论： 1、使用低热水泥和掺入粉煤灰都降低了砂浆与混凝土的早期强度,而后期强度发展速率较快；在同一养护温度条件下,水胶比越小,则同一龄期下的强度越高。 2、水工混凝土的抗压强度与其拉伸强度、拉伸弹模、极限拉应变之间存在良好的乘幂关系,并且这类关系受水泥种类和水胶比的影响较小。 3、所设实验参数对砂浆或混凝土的准绝热温升特性的影响规律一致：包含中热水泥的砂浆或混凝土的温升值及温升速率比包含低热水泥的要大；粉煤灰的掺入降低了温升值,减缓了温升速率；水胶比增大,温升值及其速率减小。 4、中热水泥砂浆的自生体积变形远比低热水泥的大,而中热水泥混凝土的自生体积变形与低热水泥混凝土的相差不大。水胶比的大小以及粉煤灰的掺入对砂浆和混凝土的自生体积变形的影响一致,即水胶比减小,自生体积收缩量增大；粉煤灰的掺入减小了自身体积收缩量,同时抑制了氧化镁的膨胀。 5、砂浆的干燥收缩与对应混凝土的干燥收缩之间具有良好的相关性,并可用二次多项式进行描述。
[Abstract]:Concrete in the actual engineering application, the ultimate tensile strength of concrete is not enough to resist the hydration heat caused by temperature stress and shrinkage shrinkage stress, lead to concrete cracks and to carry out the devastating damage to the structure. For the problem of cracking in mass concrete of hydraulic concrete has been more like concern. To solve the problem of cracking in mass concrete, performance on concrete mechanics, mechanism and characteristics of hydration heat, shrinkage deformation properties are studied, and as the most important constituent materials of concrete cementitious materials is the foundation of the research. This paper is based on the type of cement, fly ash, the ratio of experimental parameters of water glue, experimental study of hydraulic concrete cementitious system with compressive strength, flexural strength, compressive strength, concrete tensile strength, as well as the quasi adiabatic temperature rise characteristic, volume Deformation and shrinkage deformation.
The following results or conclusions can be obtained in the scope of this study:
1, the use of low heat cement and incorporation of fly ash reduced the early strength of mortar and concrete, while the later strength development rate was faster. Under the same curing temperature, the smaller the water binder ratio, the higher the strength at the same age.
2, the compressive strength of concrete and the tensile strength, tensile modulus, good power relationship between the ultimate tensile strain, and this kind of relationship is influenced by the type of cement and water cement ratio is small.
3, the influence of consistent experimental parameters on the adiabatic temperature rise characteristics of quasi mortar or concrete. The rate is bigger than the cement containing temperature and temperature in hot cement contains the appreciation of the mortar or concrete; fly ash reduces the temperature rise, slow temperature rise rate; water cement ratio temperature rise, and its speed is reduced.
4, in situ thermal cement mortar volume deformation than the cement, and moderate heat Portland cement concrete autogenous volume deformation and low heat cement concrete are similar. The water binder ratio and size of fly ash self consistent effect on volume deformation of concrete and mortar, which reduce the water cement ratio, in situ the volume shrinkage increases; fly ash reduces its volume shrinkage, while inhibiting the expansion of Magnesium Oxide.
5, there is a good correlation between the drying shrinkage of the mortar and the dry shrinkage of the corresponding concrete, and can be described by the two polynomial.

【学位授予单位】：浙江工业大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TV431

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