复掺碳酸钙晶须增强轻质ECC材料力学性能研究  

Study on the mechanical properties of lightweight EcC materials reinforced by compositecalciumcarbonatewhiskers

作　　者：王博[1] 丁庆军[2] 王君[2] 邓建平 WANG Bo;DING Qingjun;WANG Jun;DENG Jianping(School of Civil Engineering and Architecture,Wuhan University of Technology,Wuhan 430070,China;State Key Laboratory for Silicate Building Materials,Wuhan University of Technology,Wuhan 430070,China;China Railway 16th Bureau Group First Engineering Co.,Ltd.,Beijing 101300,China)

机构地区：[1]武汉理工大学土木工程与建筑学院,湖北武汉430070 [2]武汉理工大学硅酸盐建筑材料国家重点实验室,湖北武汉430070 [3]中铁十六局集团第一工程有限公司,北京101300

出　　处：《混凝土》2024年第7期133-137,共5页Concrete

基　　金：国家自然科学基金联合基金重点项目(U21A20149)。

摘　　要：工程水泥基复合材料(ECC)由于其拉伸应变硬化行为和紧密多裂缝的独特特性能够满足混凝土基础设施韧性和耐久性的严格要求。使用粉煤灰漂珠代替细石英砂作为轻质细集料,使用国内高强高模量PVA和PE纤维,并复掺碳酸钙晶须对ECC进行多尺度增强,对轻质ECC的强度、单轴拉伸性能、薄板四点弯曲性能和孔隙率等进行试验研究。结果表明:碳酸钙晶须掺量为体积的1%时最佳,PVA-ECC抗压强度为57 MPa,极限拉伸强度为4.31 MPa,拉伸应变为3.44%;而PE-ECC抗压强度为60.4 MPa,极限拉伸强度为4.77 MPa,拉伸应变为8.16%。适量的晶须掺入,能够优化孔隙结构,提升强度,晶须微观桥接作用可延缓了微观裂纹发展,同时晶须可以增加界面粗糙度,提高摩擦结合强度,从而提高ECC拉伸应变能力。Engineered cementitious composites(ECC),due to their tensile strain hardening behavior and unique characteristics of tight multiple cracks,ensure that they can meet the strict requirements of toughness and durability of concrete infrastructure.It uses fly ash floating beads instead of fine quartz sand as lightweight fine aggregates,uses domestically produced high-strength and high modulus PVA and PE fibers,and adds calcium carbonate whiskers to enhance ECC at multiple scales.The strength,uniaxial tensile performance,four point bending performance of thin plates,and porosity of lightweight ECC are experimentally studied.The results show that the optimal content of calcium carbonate whiskers is 1%by volume,with a compressive strength of 57 MPa,ultimate tensile strength of 4.31 MPa,and tensile strain of 3.44%for PVA-ECC.The compressive strength of PE-ECC is 60.4 MPa,the ultimate tensile strength is 4.77 MPa,and the tensile strain is 8.16%.Adding an appropriate amount of whiskers can optimize the pore structure and improve strength.The micro bridging effect of whiskers can delay the development of micro cracks.At the same time,whiskers can improve interface roughness and friction bonding strength,thereby improving residual energy to better meet energy criteria and thus improving tensile strain capacity.

关 键 词：工程水泥基复合材料 碳酸钙晶须 力学性能 

分 类 号：TU528.041[建筑科学—建筑技术科学]