再生保温混凝土抗冻性能的细观研究

Meso-Research on Frost Resistance of Recycled Thermal Insulation Concrete

再生粗骨料和玻化微珠保温骨料的加入,会导致再生保温混凝土(RATIC)内部形成复杂的孔隙结构。为了进一步揭示冻融作用下再生保温混凝土的劣化机理,在宏观试验的基础上,通过CT扫描细观试验分析了不同再生粗骨料取代率的RATIC试件在冻融作用下的裂缝发展规律和孔隙特征。试验结果表明:新旧水泥砂浆界面过渡区是冻融循环作用下RATIC的薄弱环节,试件内部多数裂缝产生于新旧水泥砂浆界面过渡区;试件的相对孔隙率是定量反映RATIC试件内部冻融破坏规律的重要指标。

Due to the addition of recycled coarse aggregate and glazed hollow bead insulation aggregate,the complex pore structure is formed in recycled aggregate thermal insulation concrete(RATIC).In order to further reveal the deterioration mechanism of recycled thermal insulation concrete caused by freeze-thaw action,the crack development law and pore characteristics of RATIC specimens with different replacement rates of recycled coarse aggregate under freeze-thaw action were analyzed by CT scanning microscopic test based on the macro test.The test results show that the interface transition zone between new and old cement mortar is the weak link of RATIC under freeze-thaw cycles,and most cracks in the specimens originate from the interface transition zone between new and old cement mortar.The relative porosity of specimens is the best index to quantitatively reflect the internal failure law of RATIC specimens.