基于微粉粉煤灰不同掺配比下泡沫混凝土孔隙特性分析  

Analysis of pore characteristics of foam concrete based on different mixing ratios of micro powder and fly ash

作　　者：金长慧 蒋宁山[1,3] 李辉 刘成奎[2,3] JIN Changhui;JIANG Ningshan;LI Hui;LIU Chengkui(School of Civil Engineering of Qinghai University,Xining 810016,Qinghai,China;Qinghai Building and Materials Research Co.,Ltd.,Xining 810016,Qinghai,China;The Key Lab of Plateau Building and Eco-community in Qinghai,China,Xining 810016,Qinghai,China)

机构地区：[1]青海大学土木工程学院,青海西宁810016 [2]青海省建筑建材科学研究院有限责任公司,青海西宁810016 [3]青海省高原绿色建筑与生态社区重点实验室,青海西宁810016

出　　处：《水利水电技术(中英文)》2024年第12期228-239,共12页Water Resources and Hydropower Engineering

基　　金：青海省高原绿色建筑与生态社区重点实验室开放基金计划项目(KLKF-2020-007)。

摘　　要：【目的】利用建筑垃圾制备再生微粉,不仅可以提高建筑垃圾资源的利用率,还能有效降低碳排放。【方法】采用物理发泡法以再生微粉、粉煤灰为主要原材料制备泡沫混凝土,借助X射线衍射和力学性能测试方法对不同微粉、粉煤灰掺量下泡沫混凝土的性能进行了定量表征。利用电镜扫描得到14种不同配比下的SEM图像,并结合PCAS软件对其进行孔隙分析,探究孔隙体积分形维数的变化及其与泡沫混凝土的强度和耐久性的关系。【结果】结果显示:单掺40%微粉的泡沫混凝土抗压强度最大,为6.721 MPa,孔隙率最低,为6.54%,导热系数为0.095 W/(m·K)。【结论】试样的抗压强度随着微粉掺量的增加先增大后减小,并在微粉掺量为40%时达到最大值。泡沫混凝土的孔结构具有明显的分形特征。随着微粉含量的增加,泡沫混凝土的强度随分维的减小而增大,孔隙率逐渐降低,导热系数不断下降,孔隙结构趋于规则化。再生微粉的活性被有效激发,达到固废的效果。[Objective]The use of construction waste to prepare recycled micro powder can not only improve the utilization rate of construction waste resources,but also effectively reduce carbon emissions.[Methods]Foam concrete is prepared by physical foaming method using recycled micro powder and fly ash as the main raw materials,and the properties of foam concrete were quantitatively characterized with the help of X-ray diffraction and mechanical property testing method under different micro powder and fly ash mixing ratios.SEM images are obtained by electron microscope scanning with 14 different ratios,and combined with PCAS software for pore analysis to explore the change of fractal dimension of pore volume and its relationship with the strength and durability of foam concrete.[Results]The result show that the compressive strength of foam concrete with 40% micro powder mixed alone is the largest,6.721 MPa,the porosity was the lowest,6.54%,and the thermal conductivity is 0.095 W/(m·K).[Conclusion]The compressive strength of the specimens increase and then decrease with the increase of the micro powder consumption,and reach the maximum value when the micro powder consumption is 40%.The pore structure of foam concrete has obvious fractal characteristics.With the increase of micro powder content,the strength of foam concrete increases with the decrease of fractal dimension,the porosity gradually decreases,the thermal conductivity decreases continuously,and the pore structure tends to be regularized.The activity of recycled micro powder is effectively stimulated to achieve the effect of solid waste.

关 键 词：再生微粉 PCAS 孔隙率 分形维数 影响因素 

分 类 号：TU55[建筑科学—建筑技术科学]