纳米材料改性再生骨料混凝土断裂性能  

Fracture Performance of Recycled Aggregate Concrete Modified by Nanomaterials

作　　者：罗素蓉[1] 林倩 李炜源 王德辉 LUO Surong;LIN Qian;LI Weiyuan;WANG Dehui(College of Civil Engineering,Fuzhou University,Fuzhou 350116,China)

机构地区：[1]福州大学土木工程学院,福建福州350116

出　　处：《建筑材料学报》2022年第11期1151-1159,共9页Journal of Building Materials

基　　金：国家自然科学基金资助项目(52078139)。

摘　　要：将纳米SiO_(2)(纳米硅溶胶和纳米SiO_(2)粉末)与纳米CaCO_(3)粉末加入再生骨料混凝土(RAC)中,制备得到纳米材料改性RAC.通过三点弯曲梁试验与传统电测法测试其断裂性能.结果表明:适当掺量的纳米SiO_(2)和纳米CaCO_(3)粉末能够有效提高RAC的28 d抗压强度与劈裂抗拉强度;分别掺入1.0%纳米硅溶胶、0.5%纳米SiO_(2)粉末和2.0%纳米CaCO_(3)粉末对RAC双K断裂参数和断裂能的提升效果最佳;相较普通混凝土,纳米材料改性RAC的断裂面出现更多贯通再生骨料的裂缝;纳米材料能够促进生成致密程度高的水化产物,减少混凝土界面过渡区内部的孔隙数量.Recycled aggregate concrete(RAC)was modified by adding nano-SiO_(2)(nano-silica sol and nano-SiO_(2) powder)and nano-CaCO_(3) powder to study the fracture performance.The fracture property of RAC modified by nano-materials was tested by three-point bending beam method and traditional electrical measurement.The results show that the 28 d compressive strength and splitting tensile strength of RAC can be effectively improved by adding proper amount of nano-SiO_(2) and nano-CaCO_(3).Adding 1.0%nano-silica sol,0.5%nano-SiO_(2) powder and 2.0%nano-CaCO_(3) powder respectively has the most effective on the improvement of double-K fracture parameters and fracture energy.After the addition of nanomaterials,more cracks pass through the recycled aggregate than that for ordinary concrete;nanomaterials promote production of higher density hydrate and reduction of the number of internal pore in interface transition zone.

关 键 词：再生骨料混凝土 双K断裂参数 纳米SiO_(2) 纳米CaCO_(3) 纳米压痕 

分 类 号：TU528.041[建筑科学—建筑技术科学]