自燃煤矸石轻集料混凝土碳化性能试验研究

Experiment Study on Carbonation Resistance of Spontaneous Combustion Coal Gangue Lightweight Aggregates Concrete

为探究自燃煤矸石轻集料混凝土的碳化性能,通过快速碳化试验研究抗压强度、水灰比、水泥用量、温湿度及龄期等敏感性因素对碳化深度的影响。结果表明,抗压强度与碳化近似为负相关,在24~38 MPa范围内,28 d最大减小量为9.7 mm;其他因素一定,水灰比越大,内部空隙越多,碳化深度越大;水泥用量提高1倍,碳化深度减小14.7%,单纯增加水泥用量减小其碳化程度不可取,应综合考虑其他敏感性因素;相对湿度与碳化关系呈负相关,温度与碳化关系呈正相关;在3~14 d范围时,碳化速率增长显著,超过14 d时,碳化速率增长平缓。

In order to explore the carbonation resistance of spontaneous combustion coal gangue lightweight aggregates concrete, research the impact of the sensitive factors on carbonation depth, which are compressive strength, water-cement ratio, cement dosage, temperature and relative humidity, curing period by the accelerated carbonation experiment. The results showed that the connection between compressive strength and carbonation was negative correlation, within the scope of 24-38 MPa, the maximum reduction was 9.7 mm on 28th day. If other conditions are known, the larger the water-cement ratio is, the more coal gangue concrete spacing is, the greater the carbonation depth is. When the cement dosage was doubled, the percentage of carbonation was reducing 14.7%. Simply increasing the cement dosage to decrease the carbonization degree is not optimum selection. Other sensitivity factors must be taken into account comprehensively. The relationship between relative humidity and carbonization is negative correlation, the relationship between temperature and carbonization is positive correlation. During the range of 3-14 d, the carbonation rate increased significantly, and it grown gently, when the curing period was exceeding 14 d.