原位发泡轻集料混凝土的制备与其性能表征

发布时间：2018-05-13 08:01

本文选题：轻混凝土 + 原位发泡　；参考：《安徽工业大学》2014年硕士论文

【摘要】：轻混凝土在减轻建筑地基载荷,建筑节能和建筑抗震方面具有突出的意义,而通过发泡方法获得轻混凝土是一个非常有效的手段,本文以过氧化氢溶液(质量浓度为30%)为化学发泡剂,污泥烧胀陶粒(简称“陶粒”)和膨胀珍珠岩为轻集料,通过普通化学发泡法(将H2O2直接加入水泥料浆中发泡)和对化学发泡过程控制的原位发泡法制备出一系列轻混凝土试样,并对其性能进行了系统的表征。在普通化学发泡法制备轻混凝土的研究中发现:1)轻混凝土试样的容重、力学强度和导热系数均随发泡剂量的增加而降低,当发泡剂加入量为胶凝材料质量的2%和4%时,试样的容重分别为950 kg/m3和600 kg/m3,试样的导热系数分别为0.22 W·m-1·K-1和0.18 W·m-1·K-1,比不加发泡剂的试样分别降低了25%和40%。发泡剂量为胶凝材料质量2%试样的抗压强度接近13 MPa。2)轻混凝土的干缩率随着发泡剂含量的增加而增大,当发泡剂量?胶凝材料质量的2%时,其干缩率?460×10-6。和普通化学方法相比,原位化学发泡法是先将H2O2加载在膨胀珍珠岩载体中,再通过载体间接进入轻集料之间的水泥料浆中后发泡,发泡过程和气泡分布可以被控制,为获得精细结构的轻混凝土提供了可能,文中首先制备了以膨胀珍珠岩为轻细集料,明胶为稳泡剂的原位发泡轻混凝土试样,研究中发现:1)轻混凝土试样的容重、力学强度和导热系数随发泡剂量的增加而降低;随稳泡剂量的增加而增加。当稳泡剂浓度为1.5%时,含1.4%发泡剂的试样28 d抗压强度可以高达21 MPa,2.8%发泡剂试样28 d抗压强度可高达15 MPa,其容重仅为800kg/m3。2)试样的吸水率随发泡剂量的增加而增加,随稳泡剂量的增加而降低。发泡剂为2.8%的试样,稳泡剂由1%增加到1.5%,其吸水率由26%降低到13%。另外,文中还以陶粒作轻粗集料,HPMC为增稠剂,化学发泡剂的量设定为2.8%,制备出一系列原位发泡陶粒轻混凝土试样,研究中发现增稠剂对原位发泡轻混凝土性能的影响较大。1)当增稠剂量在0.05%~0.125%范围内时,试样的容重、力学强度和导热系数随增稠剂量的增加而增加,干缩率和吸水率随增稠剂量的增加而降低。2)当增稠剂量为0.125%时,试样的28 d抗压强度为31 MPa,容重为1245 kg/m3;试样的吸水率仅为6.1%。与增稠剂量为0.05%的试样相比,增稠剂量为0.125%的试样吸水率降低了21%;干缩率降低了42%。3)增稠剂量为0.05%试样的导热系数为0.27 W·m-1·K-1。
[Abstract]:Light concrete is of great significance in reducing the load of building foundation, building energy saving and building aseismic, and obtaining light concrete by foaming method is a very effective means. In this paper, hydrogen peroxide solution (mass concentration is 30) is used as chemical foaming agent, sludge is burned expanded ceramsite ("ceramsite") and expanded perlite is used as light aggregate. A series of lightweight concrete samples were prepared by chemical foaming method (adding H2O2 directly into cement slurry) and in situ foaming method which controlled the chemical foaming process. The properties of the samples were systematically characterized. In the study of preparing light concrete by chemical foaming method, it was found that the bulk density, mechanical strength and thermal conductivity of lightweight concrete samples decreased with the increase of foaming agent content, and when the foaming agent was added to the mass of cementing material, the content of foaming agent was 2% and 4% respectively. The bulk weight of the sample is 950 kg/m3 and 600kg / m3, and the thermal conductivity of the sample is 0.22 W m-1 K-1 and 0.18 W m-1 K-1, which is 25% and 40% lower than that of the sample without foaming agent, respectively. The dry shrinkage rate of lightweight concrete increases with the increase of foaming agent content, when the amount of foaming agent is increased, when the content of foaming agent is increased, the compressive strength of the sample is close to 13MPa.2. The dry shrinkage rate of cementitious material is 460 脳 10 ~ (-6). Compared with the conventional chemical method, the in-situ chemical foaming method first loads H2O2 in the expanded perlite carrier, then indirectly enters the cement slurry between lightweight aggregates through the carrier, and then foams. The foaming process and bubble distribution can be controlled. In order to obtain the possibility of light concrete with fine structure, in this paper, the sample of in-situ foamed light concrete with expanded perlite as light fine aggregate and gelatin as foam stabilizer is first prepared. It is found in the study that the bulk weight of lightweight concrete specimen is 1: 1. The mechanical strength and thermal conductivity decreased with the increase of the amount of foaming agent, and increased with the increase of foam stabilization dose. When the concentration of foaming agent is 1.5, the 28d compressive strength of the sample containing 1.4% foaming agent can be as high as 21 MPA / 2. 8% foaming agent sample 28 days compressive strength can be up to 15 MPA, and its bulk weight is only 800 kg / m ~ (3.2) the water absorbency of the sample increases with the increase of foaming agent content. With the increase of the stable bubble dose, it decreases. When the foaming agent is 2.8%, the foam stabilizer increases from 1% to 1.5%, and the water absorption rate decreases from 26% to 13%. In addition, a series of in-situ foamed ceramic lightweight concrete samples were prepared by using ceramsite as light coarse aggregate and HPMC as thickener and chemical foaming agent as 2.8. It is found that thickener has a great influence on the properties of in-situ foamed lightweight concrete. 1) when the thickener content is in the range of 0.050.125%, the bulk density, mechanical strength and thermal conductivity of the sample increase with the increase of the thickener content. When the thickener content is 0.125, the compressive strength of the sample is 31 MPA, the bulk weight is 1245 kg / m ~ (3), and the water absorption of the sample is only 6.1 / m ~ (3). Compared with the sample with 0.05% thickener, the water absorption of the sample with 0.125% thickener decreased 21, and the dry shrinkage decreased 42%. 3) the thermal conductivity of 0.05% thickener was 0.27 W m-1 K-1.
【学位授予单位】：安徽工业大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TU528

【参考文献】