为研究氧化石墨烯(graphene oxide,GO)对水泥基复合材料路用性能的影响,制备了含不同质量分数GO的改性水泥基复合材料.采用流动度、强度和抗冻性等指标评价GO水泥基复合材料路用性能,结合扫描电镜(scanning electron microscope,SEM)与...为研究氧化石墨烯(graphene oxide,GO)对水泥基复合材料路用性能的影响,制备了含不同质量分数GO的改性水泥基复合材料.采用流动度、强度和抗冻性等指标评价GO水泥基复合材料路用性能,结合扫描电镜(scanning electron microscope,SEM)与X射线衍射(X-ray diffraction,XRD)试验探究其改性机理.结果表明,GO改性水泥基复合材料力学性能和抗冻性增幅较大,流动度有所下降;GO质量分数为0.04%时,水泥基复合材料的强度最高,其28 d抗压与抗折强度较GO质量分数为0的对照组分别提高了31.3%与44.2%;GO质量分数为0.02%时,抗冻性最好,冻融循环300次后,质量损失率仅为0.6%,残留抗压与抗折强度比分别为69%和75%.微观分析可知,GO表面的含氧亲水基团(羟基、羧基等)可为水泥水化产物结晶提供生长点,硅酸钙凝胶(C-S-H)在其上生长、交联,并且随水化龄期增长交联作用日益增强,GO可以改善水泥基复合材料的力学性能和抗冻性.展开更多
Pervious concrete is a special type of concrete that is of high porosity and contains no or a small amount of fine aggregate,and it is an important basic material for sponge city construction.The presence of a large n...Pervious concrete is a special type of concrete that is of high porosity and contains no or a small amount of fine aggregate,and it is an important basic material for sponge city construction.The presence of a large number of connected pores inside pervious concrete leads to a marked difference in durability failure mechanism compared with that of ordinary concrete.In this study,the frost resistance and anti-clogging of pervious concrete were introduced in detail,and the methods to improve their performance were summarized systematically.The cracking pattern of pervious concrete is influenced by geometric characteristics and three-dimensional morphological features of pores,resulting in its crack generation,development,and geometry being significantly different from those of ordinary concrete,thus leading to different freeze-thaw cycle mechanisms.In addition,due to its different pore structure compared to ordinary concrete,three types of clogging mechanisms,affecting the long-term permeability of pervious concrete were elaborated systematically(i.e.,physical clogging,biological clogging,and chemical clogging).And the ways to improve the anti-clogging of pervious concrete are systematically presented from multiple perspectives.Finally,in order to broaden the engineering applications of pervious concrete,some research proposals are presented in this study.展开更多
基金financially supported by the National Natural Science Foundation of China(52208246,U22A20122)the Natural Science Foundation of Hunan Province(2023JJ40142)+3 种基金the Natural Science Foundation of Changsha(kq2202160)the Provincial Special Project for the Construction of National Sustainable Development Agenda Innovation Demonstration Zone in Chenzhou City(2023sfq50)the Fundamental Research Funds for the Central Universities(531118010493)Training Program for Excellent Young Innovators of Changsha(kq2107010)。
文摘Pervious concrete is a special type of concrete that is of high porosity and contains no or a small amount of fine aggregate,and it is an important basic material for sponge city construction.The presence of a large number of connected pores inside pervious concrete leads to a marked difference in durability failure mechanism compared with that of ordinary concrete.In this study,the frost resistance and anti-clogging of pervious concrete were introduced in detail,and the methods to improve their performance were summarized systematically.The cracking pattern of pervious concrete is influenced by geometric characteristics and three-dimensional morphological features of pores,resulting in its crack generation,development,and geometry being significantly different from those of ordinary concrete,thus leading to different freeze-thaw cycle mechanisms.In addition,due to its different pore structure compared to ordinary concrete,three types of clogging mechanisms,affecting the long-term permeability of pervious concrete were elaborated systematically(i.e.,physical clogging,biological clogging,and chemical clogging).And the ways to improve the anti-clogging of pervious concrete are systematically presented from multiple perspectives.Finally,in order to broaden the engineering applications of pervious concrete,some research proposals are presented in this study.
