摘要
为了研究影响混凝土的流变参数,通过掺入引气剂改变混凝土含气量对混凝土流变性能及力学性能的影响进行分析。根据混凝土拌和物性能标准,利用混凝土流变仪、塌落度桶试验,测试混凝土的塌落度、扩展度、含气量以及流变参数,并对混凝土拌和物的流变学参数与力学性能进行分析。结果表明:在保证混凝土强度的前提下,掺用适量引气剂在混凝土拌和物内形成适量微小的封闭球状气泡,可以降低集料颗粒间的相互作用力(摩擦阻力),从而可降低屈服剪切应力和粘度、改善拌和物流变性能;引气剂掺量过大,混凝土强度下降明显。结合流变参数和抗压强度测试结果,引气剂掺量控制在0.1/10000~0.5/10000之间较为合适;提高混凝土含气量可以改善其流动性,降低泵送混凝土单位长度的压力损失。
In order to study the rheological parameters that affect concrete,the influence of changing the air content of concrete by adding air entraining agents on the rheological and mechanical properties of concrete was analyzed.According to the performance standards of concrete mixtures,using a concrete rheometer and slump bucket test,the slump,expansion,air content,and rheological parameters of concrete are tested,and the rheological parameters and mechanical properties of concrete mixtures are analyzed.The results show that,while ensuring the strength of concrete,adding an appropriate amount of air entraining agent to form a suitable amount of small enclosed spherical bubbles in the concrete mixture can reduce the interaction force(frictional resistance)between aggregate particles,thereby reducing yield shear stress and viscosity,and improving the rheological properties of the mixture.Excessive dosage of air entraining agent leads to a significant decrease in concrete strength.Based on the rheological parameters and compressive strength test results,it is more appropriate to control the dosage of air entraining agent between 0.1/10000 and 0.5/10000.Increasing the air content of concrete can improve its fluidity and reduce the pressure loss per unit length of pumped concrete.
作者
李育庆
濮国轩
刘博文
赵秋
LI Yuqing;PU Guoxuan;LIU Bowen;ZHAO Qiu(POWERCHINA SINOHYDRO ENGINEERING BUREAU 14 CO.,LTD.,Kunming 650041,China)
出处
《云南水力发电》
2024年第S01期132-135,共4页
Yunnan Water Power
关键词
泵送混凝土
含气量
流变参数
粘度
力学性能
pumped concrete
gas content
rheological parameter
viscosity
mechanical property
