废弃混凝土再生微粉对混凝土抗冻性能及气孔结构的影响  

Experimental Study on the Influence of Recycled Concrete Powder Produced by Waste Concrete on the Frost Resistance and Pore Structure of Concrete

作　　者：赵世颖 李滢[1,2] 代大虎 樊耀虎[1,2] ZHAO Shiying;LI Ying;DAI Dahu;FAN Yaohu(School of Civil Engineering,Qinghai University,Xining 810016,China;Qinghai Provincial Key Laboratory of Energy Saving Building Materials and Engineering Safety,Xining 810016,China)

机构地区：[1]青海大学土木工程学院,青海西宁810016 [2]青海省建筑节能材料与工程安全重点实验室,青海西宁810016

出　　处：《粉煤灰综合利用》2022年第1期76-81,共6页Fly Ash Comprehensive Utilization

基　　金：国家自然科学基金(51668052);青海省科学技术厅基础研究计划项目(2017-ZJ-787);青海省科学技术厅科技基础条件平台项目(2018-ZJ-T01)。

摘　　要：本文研究了利用废弃混凝土制备的再生微粉掺量、矿物掺合料复掺作用、引气剂含量等因素对混凝土抗冻性能的影响,并且通过电镜扫描、压汞法、Rapid Air等手段来分析混凝土微观结构变化与其抗冻性能之间的关系。结果表明:混凝土抗冻性能随着再生微粉掺量的增加逐步提高,当水胶比为0.35,混凝土中单掺30%再生微粉时,其抗冻次数可达175次;加入0.03%引气剂并同时复掺粉煤灰和硅灰后,混凝土内部含气量增加,气泡间距系数减小,混凝土的气孔结构明显改善,混凝土可以经受300次冻融循环作用仍不被破坏。In this paper, the effects of recycled concrete powder(RCP),mineral admixtures and air entraining agents on the frost resistance of concrete were studied, furthermore, the relationship between the microstructure change of concrete and its frost resistance performance was analyzed by means of scanning electron microscopy, mercury injection and Rapid Air, etc.The results show that the frost resistance of concrete is gradually improved with the increase of the amount of RCP,when the water-binder ratio is 0.35 and the concrete is mixed with 30% RCP,the frost resistance cycles can reach 175 times;after adding 0.03% air-entraining agent and mixing fly ash and silica fume at the same time, the air content inside the concrete increases, the bubble spacing coefficient decreases, the pore structure of concrete is obviously improved, and the concrete can withstand 300 freeze-thaw cycles without being damaged.

关 键 词：废弃混凝土 再生微粉 抗冻性能 气孔结构 

分 类 号：TU528.1[建筑科学—建筑技术科学]