基于某型泵送单元的离析混凝土可泵性边界研究  

Research on Pumpability Boundary of Segregated Concrete Based on a Pumping Unit

作　　者：邓超 胥卜轩 周开春 於劲林 Deng Chao;Xu Buxuan;Zhou Kaichun

机构地区：[1]中联重科股份有限公司 [2]国家混凝土机械工程技术研究中心

出　　处：《工程机械》2024年第5期241-245,I0022,共6页Construction Machinery and Equipment

摘　　要：混凝土离析会导致拌和物中粗骨料发生沉降,从而影响泵送施工的正常进行。混凝土离析的主要原因是拌和物中浆体无法有效包裹粗骨料,主要影响因素有骨料的粒形、水胶比及砂率等。针对离析混凝土的离析程度难以表征,可泵性评价方法不完善的现状,提出采用分层度和湿筛浆体含量等参数对混凝土拌和物离析程度进行量化表征,并结合表征结果探究水胶比、砂率对新拌混凝土离析程度的影响规律。通过对离析混凝土的分层度和湿筛浆体含量的分析,同时结合采用特定泵送单元施工时现场的泵送压力数据、出料情况,对离析混凝土的可泵性边界进行了界定。Concrete segregation will lead to the settlement of coarse aggregates in the mixture,thereby affecting the normal progress of pumping construction.The main reason for concrete segregation is that the mortar in the mixture cannot effectively wrap the coarse aggregate,and the main influence factors include the particle shape of the aggregate,water-cement ratio and sand rate.In response to the current situation that the segregation degree of segregated concrete is difficult to be characterized and the evaluation method of pumpability is imperfect,it is proposed to use parameters such as coursing degree and wet screened mortar content to quantitatively characterize the segregation degree of concrete mixture,and the influence of water-cement ratio and sand rate on the segregation degree of fresh concrete is explored by combining with the characterization results.By analyzing the coursing degree and wet screened mortar content of segregated concrete,and in conjunction with the pumping pressure data and discharge situation on site when using a specific pumping unit for construction,the pumpability boundary of segregated concrete is defined.

关 键 词：离析混凝土 可泵性 分层度 湿筛浆体含量 

分 类 号：TU528.53[建筑科学—建筑技术科学]