硫酸盐环境下再生混凝土性能试验研究  

Experiment research on properties of recycled concrete in sulfate environment

作　　者：安新正[1,2] 易成[1] 刘燕[1,3] 张结太[2] 

机构地区：[1]中国矿业大学煤炭资源与安全开采国家重点实验室,北京100083 [2]河北工程大学土木学院,河北邯郸056038 [3]河北农业大学城乡建设学院,河北保定071001

出　　处：《混凝土》2010年第7期31-33,共3页Concrete

基　　金：煤炭资源与安全开采国家重点实验室开放课题基金(SKLCRSM09KFB08);河北省建设厅科研基金(2008104)

摘　　要：用强度等级为C25废弃普通混凝土制备再生骨料,然后分别用20%(A类)和40%(B类)的再生骨料取代率来取代天然骨料,配制成再生混凝土。对再生混凝土进行了6%(质量分数)浓度的硫酸纳溶液作用下的室内侵蚀模拟试验,研究了在干-湿循环作用下硫酸纳对再生混凝土的腐蚀特性。试验结果表明:在干湿循环作用的初期阶段,对于20%和40%再生骨料取代率的再生混凝土来说,它们的动弹性模量、劈裂强度都有一定的提高,提高幅度前者略低于后者。随着干湿循环周期数的继续增加,无论是20%再生骨料取代率再混凝土,还是40%再生骨料取代率再混凝土,它们的动弹性模量和劈裂强度都开始出现缓慢下降,继而又快速下降,且后者的下降速度大大高于前者。此研究可为再生混凝土在硫酸纳环境中的工程应用提供一定参考。C25 grade waste concrete was prepared to produce the recycled aggregate with different mix proportion to replace natural aggregate in concrete.According to the objective of this study,recycled aggregate concrete will be divided into two types A and B.The substituting ratio is 20% in type A,and is 40% in type B.The experiments on corrosion of recycled aggregate concrete for types A and B were carried out under action of circulation of immersion and dry of 6%（in mass） weight of Na2SO4.The tests results show that Na2SO4 erosion has different influence on mechanical properties of recycled aggregate concrete for different substituting ratio of recycled aggregate.Their cleavage strength and relative dynamic modulus of elasticity increase gradually in the initial stage of immersion-dry cycles,and increasing rate of strength in type B was significantly higher than that in type A.the overall tendency of relative dynamic modulus of elasticity and cleavage strength were diminishing with increased immersion-dry cycle number in the later phase of immersion-dry cycles,and the stage＇s descending speed of strength in type B was significantly higher than that in type A.This research provides a reference for engineering applications of recycled aggregate concrete in Na2SO4 environment.

关 键 词：硫酸盐侵蚀 再生混凝土 动弹性模量 劈裂强度 损伤 取代率 

分 类 号：TU528.01[建筑科学—建筑技术科学]