真空脱水工艺改善混凝土抗冲磨性能试验研究

Abrasion Resistance of Hydraulic Concrete Made in Vacuum Dewatering Process

采用透水模板衬与真空脱水工艺相结合的方法浇注低水灰比混凝土,探讨以中高强度配比的真空成型混凝土达到高强混凝土抗冲磨性能的可行性.试验结果表明:降低水泥的比表面积可提高低水胶比混凝土的真空脱水率,进而提高混凝土抗冲磨性能;采用透水模板衬和真空脱水工艺相结合的方法,可使配制强度为C50的真空成型混凝土抗冲磨性能达到或超出配制强度为C70的非真空高强混凝土,由此可减少单方混凝土胶凝材料用量,有利于减少混凝土的收缩.真空脱水工艺提高混凝土抗冲磨性能的机理在于其明显降低了混凝土孔隙率,靠近表层的混凝土最可几孔径、临界孔径和平均孔径均明显减小,孔结构得到明显优化.

Low water-cement ratio concrete was made with the process of vacuum dewatering process com- bined with use of controlled permeability formwork（CPF） liner. The feasibility for the middle-strength concrete made in vacuum dewatering process to obtain the abrasion resistance of high-strength concrete was studied. Test results show that vacuum dewatering process combined with use of CPF liner can be used to increase dewatering rate and improve the abrasion resistance properties of the concrete with low water- binder ratio by taking the measure to reasonably reduce specific surface area of cement. The concrete grade of C50 made in vacuum dewatering process combined with use of CPF liner has greater abrasion resistance than that of high strength concrete grade of C70, and it is advantageous to decrease use level of binder ma- terials and reduce concrete drying shrinkage. The vacuum dewatering process can remarkably reduce con- crete porosity, and the most probable pore diameter and average pore diameter are significantly decreased, concrete pore microstructure is optimized, and hence the abrasion resistance is improved.