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(四川水利職業(yè)技術學院, 成都 611231)
摘要: 為研究再生粗骨料取代率對鹽凍循環(huán)作用下再生保溫混凝土抗凍性能的影響,對不同再生粗骨料取代率試件在鹽凍循環(huán) 0~ 100 次下的宏觀形貌、微觀形貌、氯離子濃度、質量損失率、抗壓強度和劈裂抗拉強度等指標進行對比分析. 結果表明,鹽凍循環(huán) 100 次后,再生粗骨料取代率為 0 的試件表面未發(fā)生明顯變化,再生粗骨料取代率為 30%和 50%的試件表面出現(xiàn)再生粗骨料剝落和少量漿料脫落,再生粗骨料取代率至 70%和 100%的試件表面出現(xiàn)了貫穿性裂紋和再生粗骨料剝落現(xiàn)象. 隨著鹽凍循環(huán)次數從 0 增加至 100,不同再生粗骨料取代率試件的抗壓強度和劈裂抗拉強度都呈現(xiàn)減小特征;在相同鹽凍循環(huán)次數下,再生粗骨料取代率越高則試件的抗壓強度和劈裂抗拉強度越小,再生保溫混凝土試件的抗壓強度和劈裂抗拉強度損失率都隨著鹽凍循環(huán)次數增加而增大. 鹽凍循環(huán)過程中,裂紋先在舊界面薄弱區(qū)產生,并隨著鹽凍循環(huán)次數增加而出現(xiàn)裂紋擴展并貫穿至新水泥砂漿中.
關鍵詞: 鹽凍循環(huán); 再生粗骨料; 再生保溫混凝土; 配合比設計; 抗凍性能
中圖分類號:TU528 文獻標志碼:A 文章編號:1002-848X(2023)05-0053-05
Study on frost resistance of recycled thermal insulation concrete under salt freezing cycle
GAO Jianfei, LIU Yue, SHUANG Xuezhen, YANG Chao
(Sichuan Water Conservancy Vocational College, Chengdu 611231, China)
Abstract: In order to study the effect of the replacement rate of recycled coarse aggregate on frost resistance of recycledthermal insulation concrete under the salt freezing cycle, the macroscopic morphology, microscopic morphology, chlorideion concentration, mass loss rate, compressive strength and split tensile strength of specimens with different replacementrates of recycled coarse aggregate under the salt freezing cycle 0~ 100 times were compared and analyzed. The results showthat after 100 cycles of salt freezing, there is no obvious change on the surface of the specimens with the replacement rate ofrecycled coarse aggregate of 0, the specimens with 30% and 50% of recycled coarse aggregate have spalling of recycledcoarse aggregate and a small amount of slurry shedding, and the surface of specimens with 70% and 100% recycled coarseaggregate replacement rates show through cracks and spalling phenomenon. The compressive strength and split tensilestrength of specimens with different replacement ratio of recycled coarse aggregate decrease with the increase of salt freezingcycles from 0 to 100. Under the same number of salt freezing cycles, the higher the replacement rate of recycled coarseaggregate is, the smaller the compressive strength and split tensile strength of specimens are, and the loss rate ofcompressive strength and split tensile strength of recycled thermal insulation concrete specimens are all along with thenumber of salt freezing cycles increase and increase. During the salt freezing cycle, the cracks initiate preferentially in theweak area of the old interface, and crack propagation occurs with the increase of the number of salt freezing cycles spreadand penetrate into the new cement mortar.
Keywords:salt freezing cycle; recycled coarse aggregate; recycled thermal insulation concrete; mix design; frost resistance
第一作者:高劍飛,碩士,副教授,高級工程師,主要從事土木工程結構設計、新型材料應用等方面研究,Email:gaojf665063@qq. com.
