Experimental Research on Mechanical Properties of Recycled Concrete Immersed in Chloride Solution
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摘要: 对不同浸泡龄期下的混凝土(C)、再生混凝土(RC)、钢纤维再生混凝土(SFRC)、金刚砂再生混凝土(SiCRC)等试件分别进行了立方体抗压、劈裂抗拉试验研究。将4类混凝土制成的标准立方体试块浸泡在质量分数为5%的NaCl溶液中,浸泡时间分别均为0,30,60,90 d;之后完成试验,并将得到的RC、SFRC、SiCRC等再生混凝土的力学性能与普通混凝土进行比较,通过对试验数据进行拟合,分别得到了不同类型混凝土的抗压、劈裂抗拉强度随龄期变化的关系式,并分析了不同龄期氯盐浸泡对各类再生混凝土的影响机理。结果表明:C、RC、SiCRC等混凝土的抗压、劈裂抗拉强度均随着氯盐浸泡龄期的增长而增长,而SFRC混凝土的强度性能则相反;氯盐浸泡后的SFRC试件颜色加深,且表面出现锈蚀现象,其他类型混凝土试件均无明显变化,表明SiCRC、RC和C较SFRC更适用于氯盐环境。Abstract: The specimens of concrete (C), recycled concrete (RC), steel fiber reinforced recycled concrete (SFRC) and silicon carbide recycled concrete (SiCRC) at different soaking ages were studied by compression test and splitting tensile test. Four types of standard concrete cube test blocks were immersed in a NaCl solution with a mass fraction of 5%. Soaking time was 0 d, 30 d, 60 d and 90 d, then finished the test. The mechanical properties of recycled concrete such as RC、SFRC、SiCRC were compared with ordinary concrete, the relations between the compressive strength and splitting tensile strength of different types of concrete with age were obtained by fitting the test data, and the influence mechanism of chloride salt immersion at different ages on recycled concrete was analyzed.The results showed that the compressive strength and splitting tensile strength of C,RC,SiCRC and other concrete increased with the increase of chlorine salt immersion age, while the strength performance of SFRC concrete was opposite. The color of SFRC specimens after being subjected to chlorine salt immersion was deepened and the surface was corroded. There was no obvious change in other types of concrete specimens, which indicated that SiCRC、RC and C were more suitable for chlorine salt environment than SFRC.
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Key words:
- recycled concrete /
- steel fiber /
- silicon carbide /
- different soaking age /
- experimental study /
- nonlinear fitting
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