摘要
农村大量玉米芯焚烧或占地堆放,严重污染环境且造成资源浪费。玉米芯具有轻质、保温等建筑性能,可用于制备生物质建筑材料,该研究将破碎后的玉米芯颗粒掺入再生砂浆中制备玉米芯骨料生态混凝土,通过改变胶砂比及玉米芯体积分数探讨生态混凝土的基本性能。试验结果表明:玉米芯小颗粒(4.75 mm≤直径d(27)9.5 mm)与大颗粒(9.5 mm≤d(27)19 mm)的质量比为1∶1.5时骨料的级配较合理,生态混凝土的强度较高;生态混凝土的胶砂比对干密度影响不大,但导热系数和强度则随胶砂中再生砂比重的增加而降低;随生态混凝土中玉米芯含量的增加,混凝土的干密度、导热系数及强度均明显降低。试验范围内,生态混凝土的干密度为1200~1550 kg/m^(3),导热系数为0.20~0.26 W/m·K,28 d强度为2.0~5.7 MPa。玉米芯骨料生态混凝土的研究可为开发轻质保温的墙体材料用于农业农村建设提供参考。
52 million tons of maize cobs are produced behind a huge annual output of maize each year in China.A maize cob was normally estimated as 21%of a whole maize.Previous maize cobs are generally discarded or burned as fuel,wasting natural biomass resources,while seriously polluting the environment.Currently,most maize cobs with a low utilization rate are used in the field of feeding,fungus planting,and chemical industry.Actually,maize cobs can serve as insulation materials or non-load-bearing structures,due to the high toughness,moderate strength,sound and heat insulation from the naturally porous structure.But only a few studies were focused on the utilization of maize cobs in construction.Waste concrete after crushing and screening can be an alternative way to prepare recycled aggregates with maize cobs in rural areas.In this study,a light and heat-preservation ecological concrete was fabricated,where maize cobs were broken into particles to serve as coarse aggregates in recycled mortar.The particle gradation of maize-cob aggregate was analyzed under various cement-sand ratios and maize-cob volume contents.A field test was also conducted to evaluate the performances of ecological concrete.The results show that the ecological concrete behaved a high strength with the reasonable particle gradation,when the mass ratio for the small and large particles of maize cob was 1∶1.5.There was little influence of cement-sand ratio on the dry density of ecological concrete.But the recycled sand contributed to the decrease of thermal conductivity and strength.The dry density,thermal conductivity,and strength of ecological concrete decreased obviously with the increase of maize-cob volume content.In the field test,the dry density of ecological concrete was 1200-1550 kg/m^(3,while the thermal conductivity was 0.20-0.26 W/m·K,and the 28 d strength was 2.0-5.7 MPa.The thermal conductivity was )positively correlated with the 28 d strength of ecological concrete,while both increased as the dry density increased.Ecological concrete with maize-cob aggregate can be expected to replace traditional building material in agricultural and rural construction,due to its light weight,thermal insulation,and high strength.The utilization of maize cobs in ecological concrete can alleviate agricultural wastes occupies and incineration pollution.The treatment of maize cob and recycled sand can also promote the recycling use of solid wastes in agriculture and construction in rural areas.
作者
冀晓珊
李秋义
刘娟
Ji Xiaoshan;Li Qiuyi;Liu Juan(Institute of Civil Engineering,Qingdao Agricultural University,Qingdao 266109,China)
出处
《农业工程学报》
EI
CAS
CSCD
北大核心
2021年第6期289-294,共6页
Transactions of the Chinese Society of Agricultural Engineering
基金
国家自然科学基金面上项目(51878366,52078261)
山东省自然科学基金重大基础研究项目(ZR2017ZC0737)
青岛市科技惠民示范引导专项(20-3-4-10-nsh)。
关键词
生态混凝土
复合材料
玉米芯
再生砂浆
颗粒级配
ecological concrete
composite materials
maize cob
recycled cement mortar
particle gradation
作者简介
冀晓珊,研究方向为生态混凝土性能及利用。Email:1500076992@qq.com;通信作者:刘娟,讲师,研究方向为农业固体废弃物资源化利用和开发。Email:349604216@qq.com。
