再生混凝土高强化配制方法及力学性能试验研究

发布时间：2018-05-24 21:21

本文选题：高强 + 再生混凝土　；参考：《广西大学》2015年硕士论文

【摘要】：在科技日新月异、经济浪潮全球化的今天,土木工程建设蓬勃发展。但也因此产生了诸多矛盾,建筑材料的无节制使用过度消耗了社会资源,也严重污染和破坏了自然环境。为了最大限度地缓解混凝土对资源和环境产生的一系列问题,如何改善以大量消耗资源能源的粗放型生产方式,转化为节约资源、减轻环境负担的绿色工艺,将混凝土的生产工艺转变为可持续发展的模式,成为混凝土研究与发展的必然趋势。再生混凝土在此背景下诞生。本试验在再生混凝土配合比优化设计的基础上,分别以再生粗骨料取代率、水胶比和胶凝材料用量作为试验变化参数,对高强再生混凝土的抗压性能和变形性能进行了系统研究,旨在推动高强再生混凝土在工程领域的实践应用。通过对4种再生粗骨料取代率分别为0%、30%、70%、100%,3种混凝土水胶比分别为0.28、0.32、0.36,以及3种胶凝材料用量分别为520kg/m3、 570kg/m3、620kg/m3的36组试件,每组包括立方体试件和棱柱体试件各3个,共计216个试件的试验研究,得到以下主要结论：1.本试验以配合比理论计算为基础,通过优化配合比设计,采用降低水胶比、增大胶凝材料用量和掺加矿物质掺合料等途径,在不同的粗骨料取代率30%、70%和100%下,配制出高强混凝土。当再生骨料取代率达到100%时,再生混凝土强度可达C80,这说明同样配合比的情况下,利用再生粗骨料配制高强再生混凝土是可以实现的。2.在再生粗骨料取代率、水胶比、胶凝材料用量等几个影响因素中,水胶比对高强再生混凝土强度的影响是较为显著的,即随着水胶比的增加,冉生高强混凝土的强度呈下降趋势。3.在高强再生混凝士的配制过程中,在一定程度上提高水胶比,配合适当的粗骨料取代率,既可以取得较好的强度效果,也可在实际工程中实现较好的经济效益。4.高强再生混凝土的应力—应变曲线呈现的规律与普通混凝土基本一致。无量纲应力—应变曲线显示,不论粗骨料取代率、水胶比、胶凝材料用量等因素如何变化,高强再生混凝土具有比天然混凝土更加显著的脆性性质。5.在变形性能方面,随着粗骨料取代率的增加,不同水胶比、不同胶凝材料用量下试件的延性系数也呈现不同的变化趋势。胶凝材料用量多的试件普遍呈现出延性系数略有增加的趋势,但再生粗骨料取代率为100%时,延性系数呈下降趋势的较多。6.当再生骨料取代率、水胶比、胶凝材料用量等不同因素变化时,高强再生混凝土耗能系数变化规律与延性系数变化规律基本一致。
[Abstract]:With the rapid development of science and technology and the globalization of economy, the construction of civil engineering is booming. However, there are many contradictions. The excessive use of building materials consumes social resources and pollutes and destroys the natural environment. In order to alleviate a series of problems caused by concrete to resources and environment to the maximum extent, how to improve the extensive mode of production, which consumes a lot of resources and energy, and transforms it into a green process that saves resources and lightens the burden of environment. It is an inevitable trend of concrete research and development to change the concrete production technology into a sustainable development model. Recycled concrete was born in this background. On the basis of optimum design of recycled concrete mixture ratio, the replacement ratio of recycled coarse aggregate, the ratio of water to binder and the amount of cementitious material are respectively used as the experimental parameters. The compressive and deformation properties of high strength recycled concrete are studied systematically in order to promote the practical application of high strength recycled concrete in engineering field. The ratio of water to binder of three kinds of concrete was 0.280.32 / 0.36, and the dosage of three kinds of cementing materials was 520kg / m ~ 3, respectively. The 36 groups of 570kg/m3620kg/m3 were divided into three groups: cube specimen and prism specimen, each group consisted of three cube specimens and three prism specimens. The ratio of water to binder was 0.28 kg / m ~ (3), respectively, and the ratio of three kinds of cementing materials was 520kg / m ~ (3), respectively. A total of 216 specimens were tested and the following main conclusions were obtained: 1. Based on the theoretical calculation of mixture ratio, by optimizing the mix ratio design, reducing the water / binder ratio, increasing the amount of cementitious material and adding mineral admixture, etc., under the conditions of different coarse aggregate substitution rate of 30% and 100%, High strength concrete is prepared. When the replacement ratio of recycled aggregate is 100, the strength of recycled concrete can reach C80, which shows that it is possible to use recycled coarse aggregate to prepare high strength recycled concrete with the same mix ratio. Among the influencing factors such as the replacement ratio of recycled coarse aggregate, the ratio of water to binder and the amount of cementitious material, the effect of water / binder ratio on the strength of high strength recycled concrete is more significant, that is, with the increase of water / binder ratio, The strength of Ransheng high strength concrete shows a downward trend. In the process of preparation of high strength regenerated coagulant, to a certain extent, the ratio of water to binder and the replacement rate of coarse aggregate can be improved to a certain extent, which can not only obtain better strength effect, but also achieve better economic benefit in practical engineering. The stress-strain curve of high strength recycled concrete is basically consistent with that of ordinary concrete. The dimensionless stress-strain curves show that high strength recycled concrete has more brittleness than natural concrete, regardless of the change of coarse aggregate replacement ratio, water / binder ratio and the amount of cementitious material. In the aspect of deformation properties, the ductility coefficient of the specimens with different water / binder ratio and different amount of cementitious material also shows a different trend with the increase of coarse aggregate replacement ratio. The ductility coefficient of the specimens with more cementitious materials is increasing slightly, but when the replacement ratio of regenerated coarse aggregate is 100, the ductility coefficient is more. 6. When the replacement ratio of recycled aggregate, the ratio of water to binder and the amount of cementitious material are changed, the variation of energy dissipation coefficient of high strength recycled concrete is basically consistent with that of ductility coefficient.
【学位授予单位】：广西大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TU528

【参考文献】