摘要
为了有效提高再生粗骨料的性能,必须对再生骨料进行机械强化处理．首次提出了利用高速(线速度≥80 m/s)运动的再生骨料之间的反复相互冲击与摩擦作用,有效地打掉较为突出的棱角和除去颗粒表面附着的砂浆和水泥石的一种新技术．研究表明:颗粒整形使再生骨料的颗粒堆积密度平均提高了9．3％、表观密度从2．56 g/cm3提高到2．59 g/cm3、空隙率从53．3％降至48．5％、吸水率从4．7％降至2．9％、压碎指标值从15．8％降至9．4％,而且堆积密度、密实密度和针片状骨料含量等指标均优于天然碎石骨料,完全能够满足配制普通混凝土的要求．
If coarse aggregates from crushed old concrete are to be used in concrete technology, they ought to be treated in order to improve the quality of the new concrete. In this contribution a new processing technique to produce high quality recycled coarse aggregates is described. By using repeating reciprocity of striking and rubbing between aggregates at high speed （velocity can reach to at least 80 m/s）, adhering mortar on the surface of the coarse aggregates can be taken off and sharp edges broken so that the surface of the coarse aggregates becomes smoother. The particle processing technique described in this paper is simple and high output can be obtained at low cost. The production of high quality recycled aggregates can be introduced into practice immediately. Experimental results show that concrete made with aggregates, which have been processed by means of this particle shape correcting processing technique, will have significantly improved properties. The particle bulk density increases by 9.3 % on average. The density of the particles increases from 2.56 g/cm^3 to 2.59 g/cm^3. The porosity decreases from 53.3 % to 48.5 % and the water absorption decreases from 4.7 % to 2.9 %. The values obtained by a crushing test decreases from 15.8 % to 9.4 %. After processing, the bulk density, the density, and the content of needle-like and flaky aggregates are better for use in concrete technology as compared to natural aggregates. For this reason, the processed recycled aggregates can be used to produce ordinary concrete with good quality.
出处
《材料科学与工艺》
EI
CAS
CSCD
北大核心
2005年第6期579-581,585,共4页
Materials Science and Technology
基金
国家十五科技攻关资助项目(2004BA809B0305)
关键词
再生骨料
破碎
整形
粒形
性能
recycled aggregate
crushing
processing
aggregate shape
properties
作者简介
李秋义（1963-），男，博士，教授．E-mail：lqy@qtech．edu．cn
