纳米CaCO3对再生混凝土力学性能的影响研究  

Effect of nano-CaCO3 on mechanical properties of recycled aggregate concrete

作　　者：曲成平[1] 孙燕群 张鹏[1] QU Chengping;SUN Yanqun;ZHANG Peng(School of Civil Engineering,Qingdao University of Technology,Qingdao 266033,China)

机构地区：[1]青岛理工大学土木工程学院,山东青岛266033

出　　处：《混凝土》2020年第9期82-84,87,共4页Concrete

基　　金：国家自然科学基金(51778309);山东省自然科学基金(ZR2018JL018)。

摘　　要：研究了纳米CaCO3对再生骨料混凝土力学性能的强化效应,按水胶比0.5,再生骨料取代率分别为70%、30%配制再生骨料混凝土(RAC-1、RAC-2),并以相同取代率制备纳米CaCO3强化再生骨料混凝土(RNC-1、RNC-2),设置基准组(NAC),进行了基本力学性能试验。结果表明,RNC-1、RNC-2组混凝土的3、7 d抗压强度较NAC组略有提高,但与未强化的再生骨料混凝土RAC-1、RAC-2相比大幅提高,28 d时RNC-1组强度较NAC组略有下降,RAC-2组则与之结果相近,但较RAC-1、RAC-2组仍有较大提高。表明纳米CaCO3溶液对再生骨料的强化作用明显,且早期效果优于后期。对比28 d时的抗折强度、折压比,在相同取代率的情况下,经强化后RNC-1、RNC-2组混凝土的抗折强度提高显著,韧性有所改善。The effect of nano-CaCO3 on mechanical properties of recycled aggregate concrete has been studied.Concrete specimens with water-to-binder ratio of 0.5 and the replacement ratio of recycled aggregates with 70%and 30%have been prepared,respectively.Recycled aggregate concrete(RAC-1,RAC-2),and prepared nano-CaCO3 enhanced recycled aggregate concrete(RNC-1,RNC-2)with the same substitution rate,and the reference group(NAC)were prepared.The basic mechanical properties tests have been performed.Results indicated that,the compressive strength of RNC-1 and RNC-2 concrete at 3 d and 7 d is only slightly higher than that of NAC group,but it is much higher than RAC-1 and RAC-2.At 28d,the compressive strength of RNC-1 was slightly lower than that of NAC group,and the result of RAC-2 group was similar,but it was much more improved compared with RAC-1 and RAC-2 group.This indicates that the nano-CaCO3 solution has obvious strengthening effect on the recycled aggregate.And the effect is better at the early stage than the later stage.Compared with the flexural strength and the compression ratio at 28d,the flexural strength of the RNC-1 and RNC-2 groups was significantly improved,and the toughness was improved after the same substitution rate.

关 键 词：纳米CACO3 再生混凝土 力学性能 

分 类 号：TU528.01[建筑科学—建筑技术科学]