脱硫石膏-粉煤灰道路混凝土配制及开裂敏感性研究

Study on Cracking sensitivity and preparation of highway concrete with Flue Gas desulfurization gypsum and Fly Ash

利用脱硫石膏对粉煤灰活性SiO2、Al2O3激发效应,掺入脱硫石膏—粉煤灰20%～40%,其中脱硫石膏∶粉煤灰=1∶2,制备道路混凝土。通过试验研究该混凝土主要技术性能,结果表明,该混凝土施工工作性良好、28 d抗压强度均达到或大于C35、抗折强度优良,随着脱硫石膏—粉煤灰掺量增加,混凝土主要技术性能呈先增大后减小的趋势。改进的自创平板加速开裂实验结果表明,粉煤灰微骨料支撑作用及脱硫石膏微膨胀性能共同赋予混凝土优异的抗裂性,未出现肉眼可见裂纹。综合试验结果,推荐脱硫石膏—粉煤灰掺量为20%～30%。

Using of flue gas desulfurization gypsum priming effect to fly ash activity SiO2,Al2O3,highway concrete was produced by blending flue gas desulfurization gypsum and fly ash,flue gas desulfurization gypsum-fly ash replacing 20%~40% equivalent cement,flue gas desulfurization gypsum ∶ fly ash=1 ∶ 2.The concrete main technical performances were tested.The results indicated that this concrete was excellent in workability and rupture strength,28 d compressive strength was reaching or greater than C35.The flat plate test designed and improved by authors indicated that concrete early cracking resistance,bestowed by the fly ash micro aggregate support function and flue gas desulfurization gypsum micro expansion performance,was better than ordinary concrete,cracks were not be found.Considering the above results,flue gas desulfurization gypsum and fly ash replacing 20%~30% cement is recommended.