湿热地区生物炭透水混凝土的热湿性能  

Hygrothermal properties of biochar-modified pervious concrete in hot and humid area

作　　者：吴维 谭康豪 张云寒 汪俊松[3] WU Wei;TAN Kanghao;ZHANG Yunhan;WANG Junsong(School of Civil Engineering and Architecture,Key Laboratory of Disaster Prevention and Engineering Safety of Guangxi,Guangxi University,Nanning 530004,P.R.China;College of Architecture and Civil Engineering,Beijing University of Technology,Beijing 100044,P.R.China;State Key Laboratory of Subtropical Building Science,South China University of Technology,Guangzhou 510640,P.R.China)

机构地区：[1]广西大学土木建筑工程学院,工程防灾与结构安全教育部重点实验室,南宁530004 [2]北京工业大学建筑工程学院,北京100044 [3]华南理工大学亚热带建筑科学国家重点实验室,广州510640

出　　处：《土木与环境工程学报（中英文）》2023年第4期173-181,共9页Journal of Civil and Environmental Engineering

基　　金：国家自然科学基金(51678243、51678164);广西研究生教育创新计划资助项目(YCBZ2021022)。

摘　　要：透水混凝土因丰富的孔隙结构而具有良好的渗透和调湿性能,不仅能渗透降雨以减少地表径流,还能在内部截留一定的水分并通过水分蒸发降低表面温度。为提高透水混凝土的保水性以延长其降温效果,利用农业废弃物制成生物炭作为保水填料,并按照一定质量比取代水泥,制备出生物炭透水混凝土,分析生物炭对透水混凝土力学性能的影响,进而在最佳取代率下探讨生物炭对透水混凝土的热物参数和吸水蒸发降温性能的影响。结果表明:当生物炭取代率小于5.0%时,研磨后的超细炭颗粒可以充分发挥填充和内固化效应,有效提高透水混凝土的力学性能;生物炭的掺入对其发射率影响并不显著,但降低了反射率和导热系数;生物炭具有较高的比表面积和丰富的孔隙,添加到透水混凝土后能显著提高其毛细吸水能力和保水能力,而额外吸收的水分能有效降低其表面温度3~6℃,维持14~18 h的蒸发冷却效果。Pervious concrete has good permeability and moisture adjustment properties due to its rich pore structure.It can not only penetrate rainfall to reduce surface runoff,but also retain a certain amount of water inside then via evaporation to decrease surface temperature.In order to improve the water retention of pervious concrete and prolong its cooling effect,this study introduced a modified method of incorporating biochar produced by pyrolyzing agricultural wastes into pervious concrete as hygroscopic filler.The effects of biochar on the mechanical properties of pervious concrete were analyzed,then the thermophysical properties,water absorption properties and evaporative cooling performance of biochar-modified pervious concrete with the optimum replacement rate were studied.The results show that the carbonaceous particles after grinding could fully exert the filling and internal curing effects when the replacement rate was less than 5.0%,and effectively improve the mechanical strength of pervious concrete.It was found that the biochar addition had little impact on the emissivity of pervious concrete,while significantly reduced the reflectivity and thermal conductivity.Contributing to the abundant micro-pores and higher specific surface area of biochar particles,it could improve capillary water absorption and water storage ability of pervious concrete.During the evaporation process,the water absorption increment could effectively reduce surface temperature of 3-6℃and maintain evaporation cooling effect for 14-18 h.

关 键 词：农业废弃物 生物炭 透水混凝土 保水能力 蒸发降温 

分 类 号：TU528.1[建筑科学—建筑技术科学]