粉煤灰品质对混凝土性能影响研究

研究掺低钙、高钙粉煤灰对结构混凝土坍落度、抗压强度、混凝土碳化、氯离子扩散系数、干湿循环破坏等性能的影响.研究表明低钙、高钙粉煤灰对混凝土坍落度没有影响,在相同的养护龄期里掺高钙粉煤灰的混凝土抗压强度大于低钙粉煤灰混凝土.掺加低钙、高钙粉煤灰对混凝土碳化、氯离子扩散系数、干湿循环破坏有影响,掺加低钙粉煤灰混凝土具有比掺高钙粉煤灰混凝土更大碳化深度,掺低钙、高钙粉煤灰对混凝土氯离子扩散系数影响不明显,在干湿循环初始阶段掺低钙粉煤灰混凝土抗压强度、相对动弹性模量增加程度大于掺高钙粉煤灰混凝土增加程度,干湿循环超过30次后高钙粉煤灰混凝土抗压强度、相对动弹性模量劣化增加程度小于低钙粉煤灰混凝土抗压强度劣化损伤增加程度.

The Effect of Fly Ash Qualify on the Properties of Concrete

The effect of high and low lime fly ash on the fluidity,compressive strength and long-term properties(carbonation,chloride ion diffusion coefficient,drying-wetting cycles)of concrete was studied.The test results showed that concrete with high and low lime fly ash have same slump of concrete,concrete with high lime fly ash has a higher compressive strength than that of low lime fly ash at the same curing period,the high and low lime fly ash have also effect on the carbonation depths,chloride ion diffusion coefficient and the damage under drying-wetting cycles of concrete,concrete with low lime fly ash has a higher carbonation depth than that of high lime fly ash,the high and low lime fly ash have not effect on chloride ion diffusion coefficient of concrete,the effect of high and low lime fly ash on deteriorate properties of concrete under drying-wetting cycles was studied,the parameter was the weight lost,the relative compressive strength and the relative dynamic of elasticity,the result indicates that concrete with low lime fly ash has a larger the relative compressive strength,relative dynamic of elasticity than concrete with high lime fly ash at the initial stage of drying-wetting cycle,the deteriorate degree of concrete with high lime fly ash is less than concrete with low lime fly ash after 30 days of dry-wet cycle.