多孔水泥混凝土力学性能试验研究  

Effect of aggregate type and gradation on the performance of porous cement concrete

作　　者：李蒙强 靳斌 喻敏 曹毅 肖丹 李曦 LI Meng-qiang;JIN Bin;YU Min;CAO Yi;XIAO Dan;LI Xi(China Construction West Construction Hunan Co. Ltd., Changsha 410114, China)

机构地区：[1]中建西部建设湖南有限公司,湖南长沙410114

出　　处：《长沙理工大学学报（自然科学版）》2018年第4期23-31,共9页Journal of Changsha University of Science and Technology:Natural Science

摘　　要：为研究多孔水泥混凝土的力学性能,考虑了玄武岩碎石与河卵石的2种单一粒级9.5～13.2mm和13.2～16.0mm以及孔隙率分别为18%、22%和26%的情况,运用CT扫描和万能试验机等技术手段,获得了多孔水泥混凝土内部孔径大小分布规律及其弹性模量等。研究结果表明,水灰比过大、过小均会造成孔隙与浆体分布不均匀,水泥的最佳用量以刚好能够完全包裹粗骨料的表面为适度;孔隙率受骨料类型、骨料粒径以及骨料体积比影响较大;与碎石相比,卵石制备多孔水泥混凝土弹性模量与抗压强度之间离散性较大;在不同应力条件下,受压8,24h后,多孔水泥混凝土抗压强度明显不同。In order to study the mechanical properties of porous cement concrete,two kinds of single-grain grades of basalt gravel and river pebbles are considered to be9.5to13.2mm,13.2to16.0mm,and the porosity is18%,22%,and26%,respectively.Using CT scanning,universal testing machine and other technical means,the pore size distribution of porous cement concrete and its elastic modulus are obtained.The research shows that the water-cement ratio is too small,the cement inside the porous cement concrete can not be fully hydrated,and the uniform and continuous cementation layer can not be formed between the aggregate particles;the water-cement ratio is too large,the cement slurry is easy to flow and segregate,resulting in uneven distribution of pores and slurry.The optimum amount of cement is moderately just enough to completely wrap the surface of the coarse aggregate;the porosity is greatly affected by the type of aggregate,aggregate size and aggregate volume ratio,and the porosity is larger,porous cement.The cement slurry in the concrete is relatively reduced,the slurry coating on the aggregate surface is thinned,the bond strength is reduced,and the compressive strength is reduced.Compared with the crushed stone,the dispersion between the elastic modulus and the compressive strength of the porous cement concrete prepared by the pebble is compared.Under different stress conditions,the compressive strength of porous cement concrete is significantly different after8h and24h pressure.

关 键 词：水灰比 孔隙率 抗压强度 弹性模量 应力历史 

分 类 号：TU528[建筑科学—建筑技术科学]