碱激发凝灰岩石粉与骨料复合体系的强度与收缩率研究  

INVESTIGATION ON STRENGTH AND SHRINKAGE RATE OF ALKALI-ACTIVATED TUFF POWDER AND AGGREGATES COMPOSITE

作　　者：侯普林 张彤炜 于子豪 邓永锋[3] 兰恒星 窦晖[6] 徐华鑫 HOU Pulin;ZHANG Tongwei;YU Zihao;DENG Yongfeng;LAN Hengxing;DOU Hui;XU Huaxin(Key Laboratory of Mechanics on Disaster and Environment in Western China,MOE,Lanzhou University,Lanzhou 730000,China;College of Civil Engineering and Mechanics,Lanzhou University,Lanzhou 730000,China;Institute of Geotechnical Engineering,School of Transportation,Southeast University,Nanjing 210096,China;School of Geological Engineering and Geomatics,Chang an University,Xi'an 710064,China;Institute of Geographic Science and Natural Resources Research,Chinese Academy of Sciences,Beijing 100101,China;Gansu Road and Bridge Construction Group Co.,Ltd,Lanzhou 730015,China)

机构地区：[1]兰州大学西部灾害与环境力学教育部重点实验室,兰州730000 [2]兰州大学土木工程与力学学院,兰州730000 [3]东南大学交通学院岩土工程研究所,南京210096 [4]长安大学地质工程与测绘学院,西安710064 [5]中国科学院地理科学与资源研究所,北京100101 [6]甘肃路桥建设集团有限公司,兰州730015

出　　处：《工程地质学报》2022年第5期1414-1426,共13页Journal of Engineering Geology

基　　金：国家自然科学基金(资助号:42041006);甘肃省自然科学基金项目(资助号:20JR5RA259);中国博士后科学基金面上项目(资助号:2019M653791);中央高校基本科研业务费专项资金(资助号:lzujbky-2021-ct04);甘肃省路桥建设集团有限公司科技项目.

摘　　要：在天然地质体中寻求绿色胶凝材料是“双碳”背景下的研究热点,凝灰岩石粉作为机制砂生产过程中的固体废弃物,其与骨料复合体系的强度与收缩性能研究鲜有报道。本文制备了碱激发石粉浆、石粉-砂浆和石粉-砂-碎石浆3组样品,经过60℃养护后,测试了其抗压强度、劈裂抗拉强度和收缩率等工作性能。结果显示,由于骨料形成的薄弱界面与热膨胀率的差异,碱激发石粉抗压强度(12.7MPa)大于石粉-骨料复合材料强度(4.4~7.0MPa),压缩模量呈现相同的变化规律。凝灰岩骨料由于与石粉成分相同,表面的溶解和聚合反应使骨料复合材料强度更高。随着砂、碎石的加入,试样收缩率减小,最小收缩率为0.4%。由于疏水、减弱胶结强度和阻止表面反应,荷叶疏水剂与熟桐油降低了碱激发石粉、石粉粗骨料体系的强度。具有保水效果的SRA减缩剂对强度的影响最小。对于碱激发石粉试样,荷叶疏水剂、熟桐油和SRA减缩剂对收缩的抑制作用不明显。对于石粉-砂试样,SRA的减缩效果最优(0.9%)。对于石粉-砂-碎石试样,未添加外加剂的试样收缩率更低,说明石粉与骨料复合体系的收缩率主要受骨架作用影响。最终,通过交叉试验比选出碱激发石粉、石粉-砂和石粉-砂-碎石3种材料的最优配比。Under the carbon peaking and carbon neutrality goals,seeking green cementitious materials from natural geomaterials is widely focused.The fine tuff powder is a solid waste produced in the process of manufactured sand production,and is a natural silica-aluminum geopolymer.There are few studies on the strength and shrinkage properties of tuff powder and aggregate composite.We select quartz tuff powder,blast furnace slag,sand,gravel and hydrophobic agent as raw materials to prepare alkali activated tuff powder slurry,tuff powder mortar and tuff-based concrete.After 60℃curing,the compressive strength,splitting tensile strength and shrinkage of the composites are investigated.The influences of each component on their physical and mechanical properties are analyzed.The results showed that the compressive strength of alkali activated tuff powder without additive is 12.7MPa and is higher than that of tuff powder and aggregate composite(of 4.4~7.0MPa).The results are attributed to the weak interfaces formed by the aggregate adding and different thermal expansion rates of aggregate and paste.The compression modulus of samples also is reduced when the sand and crushed stone are added in the composite.The mineral composition of tuff powder is similar to that of tuff aggregate.Due to the depolymerization and polymerization reaction under the action of alkali activator,the hydrated calcium aluminosilicate and hydrated sodium aluminosilicate are formed on particle surface.Then,the strengths of tuff powder and tuff aggregate composite are higher.With the addition of sand and gravel,the shrinkage of the sample decreases.The minimum shrinkage is 0.4%for the tuff powder,quartz sand and tuff gravel composite.For the hydrophobicity,bonding strength weakening and surface reaction preventing,the Lotus leaf hydrophobic agent(LHG)and Boiled wood oil(BWO)reduce the strength of tuff based geopolymer and tuff powder-sand-gravel composite.The strength of samples with shrinkage reducing agent(SRA)is higher than that of LHG and BWO groups,wh

关 键 词：凝灰岩石粉 凝灰岩石粉-骨料复合体系 收缩率 强度 变形模量 

分 类 号：TU528[建筑科学—建筑技术科学]