Experimental Research on Mechanical Properties of Concrete After Carbonization at High Temperatures
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摘要: 通过对混凝土试件进行碳化高温试验,研究混凝土碳化深度、质量损失及碳化高温后抗压与抗折强度的变化规律,分析碳化高温后混凝土力学性能衰减机理,建立基于碳化高温后混凝土质量损失率的抗压强度及抗折强度计算式。研究表明:随着碳化的不断进行,混凝土碳化深度和质量损失随之增大;碳化龄期为7,14,28 d时,混凝土抗压强度随温度升高先减小后增大然后再减小,碳化龄期为14,28 d的抗压强度峰值出现在400 ℃;混凝土抗折强度总体趋势是随温度升高而降低,但在碳化龄期14,28 d、温度200 ℃时,其抗折强度略有升高。利用基于碳化高温后混凝土质量损失率的抗压及抗折强度计算式,可预估不同碳化龄期、不同温度下混凝土的抗压、抗折强度。Abstract: Through the high temperature test of the concrete after carbonization, the change rules of carbonization depth, mass loss, compressive strength and flexural strength were studied; the degradation mechanism of the mechanical properties of concrete after high-temperature carbonization was analyzed; the calculation formulas of compressive strength and flexural strength based on the mass loss ratios of concrete at high temperatures after carbonization were established. The results showed that with the continuons carbonization of concrete, the carbonization depth and mass loss increased; when the carbonization age was 7 d, 14 d, 28 d, the compressive strength of concrete decreased first, then increased and then decreased with the increase of temperature; the peak vale of the compressive strength of concrete with carbonization age of 14 d or 28 d appeared at 400 ℃; the general trend of the flexural strength of concrete decreased with the increasing temperature, but when the carbonization age was 14 d or 28 d and the temperature was 200 ℃, its flexural strength would increase slightly; the calculation fomulas of the compressive strength and flexural strength based on the mass loss ratios of concrete could be used to predict the compressive strength and flexural strength of concrete at different carbonization ages and different temperatures.
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Key words:
- carbonation /
- high temperature /
- carbonation depth /
- mass loss /
- compressive strength /
- flexural strength
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