Development of limestone calcined clay cement concrete in South China and its bond behavior with steel reinforcement  

华南地区煅烧粘土-石灰石复合水泥(LC^3)混凝土的研发及其与钢筋的粘结性能

作　　者：Zhen-yu HUANG You-shuo HUANG Wen-yu LIAO Ning-xu HAN Ying-wu ZHOU Feng XING Tong-bo SUI Bin WANG Hong-yan MA 

机构地区：[1]Guangdong Provincial Key Laboratory of Durability for Marine Civil Engineering,Shenzhen University,Shenzhen 518060,China [2]Department of Civil,Architectural and Environmental Engineering,Missouri University of Science and Technology,Rolla,MO 65401,USA [3]Si noma Research Institute,Si noma International Engineering Co.,Ltd.,Beijing 100102,China

出　　处：《Journal of Zhejiang University-Science A(Applied Physics & Engineering)》2020年第11期892-907,共16页浙江大学学报（英文版）A辑（应用物理与工程）

基　　金：the National Natural Science Foundation of China(Nos.51708360 and 51978407);the Shenzhen Basic Research Project of China(No.JCYJ20180305124106675);the Key Projects for International Cooperation in Science;Technology and Innovation of China(No.2018YFE0125000);the Taipei University of TechnologyShenzhen University Joint Research Program of China(No.2020008);the National Science Foundation of the USA(No.1661609);the Advanced Materials for Sustainable Infrastructure Seed Funding Program at Missouri University of Science and Technology,USA。

摘　　要：Limestone calcined clay cement(LC^3),consisting of ordinary Portland cement(OPC)clinker,calcined clay,limestone powder,and gypsum,has been considered a promising solution to current challenges in the cement and concrete industry,such as high carbon emissions,high energy consumption,and resource shortages.This study carries out a series of experimental investigations of LC^3-based paste,mortar,and concrete,including microstructural analyses(e.g.hydration product characterization and pore structure analysis)and macro-scale testing(e.g.workability and mechanical properties),using raw materials from south China.The results show that,in LC^3 paste,the replacement of clinker by calcined clay and limestone leads to an increased volume of small pores but decreased total volume of pores.The workability of LC^3 mortar and concrete can be readily tailored using conventional superplasticizers.When designed for comparable 28-d compressive strength,the LC^3 mortar and concrete tend to have lower early-age compressive strength,but comparable compressive strength and higher flexural strength than those of the OPC counterparts at late ages.This study also examines the bond-slip behavior between LC^3 concrete and steel bars and finds that the bond strength is comparable to that of OPC concrete with the same 28-d compressive strength,but that the LC^3 concrete-rebar interface exhibits higher bond-slip stiffness.These findings on LC^3 concrete provide fundamental information and guidance for furthering the application of LC^3 binder in structural concrete in the near future.目的:采用华南地区的原材料研发一种LC3水泥胶凝材料,并研究其水化反应、微观结构的发展、工作性能、强度性能的发展以及混凝土和钢筋之间的粘结-滑移行为,为推广LC3水泥胶凝材料应用于滨海结构混凝土提供基础信息和参考。创新点:1.鉴于目前对LC3水泥胶凝材料在混凝土技术和结构混凝土中的应用研究较少,本文对采用华南地区原材料制备的LC3混凝土进行了技术研究和应用分析;2.试验结果发现,LC3混凝土的抗折和劈裂性能优于相同抗压强度的普通混凝土;3.采用拔出试验研究LC3混凝土与钢筋之间的界面粘结-滑移行为,证明了新型LC3水泥胶凝材料在钢筋混凝土结构中的适用性。方法:1.开展一系列基于LC3水泥的净浆、砂浆和混凝土的实验研究,并使用原始材料进行微观结构分析(水化产物表征和孔结构分析)和宏观测试(工作性能和力学性能测试)。2.研究LC3混凝土与钢筋之间的粘结-滑移行为。结论:1.与普通混凝土(OPC)相比,钙矾石、单碳铝酸盐(MC)和半碳铝酸盐(HC)是LC3样品中的主要晶体水合产物;由于熟料减少50%,且LC3中发生的二次水化反应消耗了大量OPC熟料水化生成的氢氧化钙(CH),因此在LC3的水合产物中几乎没有残留六角形薄片CH。2.与OPC砂浆和混凝土相比,LC3砂浆和混凝土的早期强度较低;由于在煅烧粘土中无定形二氧化硅和氧化铝(与石灰石结合)二次反应形成了更多的水化硅酸钙和碳铝酸钙水合物,LC3砂浆和混凝土的后期强度(7天后)迅速增加至与OPC砂浆和混凝土相当的强度水平。3.在与OPC同类材料具有相同抗压强度的情况下,LC3水泥胶凝材料具有更高的抗折和劈裂强度,因此更有韧性。4.对于LC3水泥胶凝材料,颗粒更细的石灰石不一定会带来更好的力学性能。5.对于混凝土与钢筋之间的界面粘结-滑移行为,LC3的破坏模式与OPC大致相同,且通常有两种破�

关 键 词：Limestone calcined clay cement(LC^3) Hydration BOND-SLIP Mercury intrusion porosimetry(MIP) Scanning electron microscope(SEM) Bond strength 

分 类 号：TU528.59[建筑科学—建筑技术科学]