再生混凝土层裂强度的试验研究  

Experimental study on spalling strength of recycled concrete

作　　者：于水生[1] 卢玉斌[2] 蔡勇[2] 滕骁[2] 陈兴[2] 

机构地区：[1]东北大学资源与土木工程学院,辽宁沈阳110819 [2]西南科技大学制造过程测试技术教育部重点实验室,四川绵阳621010

出　　处：《混凝土》2015年第11期79-82,共4页Concrete

基　　金：国家自然科学基金资助(51308480)

摘　　要：利用大直径（75 mm）分离式霍普金森压杆（SHPB）对再生粗骨料取代率分别为0,25%、50%、75%和100%的再生混凝土进行层裂试验,研究不同再生粗骨料取代率下再生混凝土的层裂性能及其破坏状况。试验结果表明：再生混凝土层裂强度随着加载率的增加而增大,并且影响着再生混凝土的断口形状和破坏形态,具有较强的加载率敏感性;混凝土破坏状态不仅表现为粗骨料和水泥砂浆界面的破坏,而且与骨料的断裂破坏有关;在相同水灰比下,普通混凝土的层裂强度高于其他取代率的,对于取代率为50%、75%和100%而言,在加载率为100～200 GPa/s之间,再生混凝土的层裂强度相近。此研究为再生混凝土的工程应用提供一定的理论依据。To study the recycled concrete spalling properties and fracture state with various recycled coarse aggregate replacement per- centage （0,25%,50%,75%and 100% ）, the dynamic spalling test of recycled concrete was carried out using large diameter （75 mm）split Hopkinson pressure bar（ SHPB ）. The results show that the recycled concrete spalling strength increases with the increase of loading rate, and the loading rate also affects the recycled concrete fracture shape and fracture patterns ,which indicates that the recycled concrete has obvious loading - rate sensitivity.The damage state of the recycled concrete is not only the destruction of the interface between coarse aggregate and cement mortar, but also associates with the fracture damage of aggregates. Under the same water cement ratio, the spalling strength of normal concrete is higher than that of other replacement percentage ,for the replacement percentage of 50% ,75%and 100%, the spalling strengths of recycled concrete are similar when the loading -rate are between 100 and 200 GPa/s.It offers theoretical basis for the engineering applications of recycled concrete.

关 键 词：再生混凝土 再生粗骨料 取代率 SHPB 层裂实验 加载率效应 

分 类 号：TU528.01[建筑科学—建筑技术科学]