随着全国城镇化进程的加速造成预拌混凝土的运输距离不断扩大,大中城市的拥堵效应造成预拌混凝土的运输时间随之延长,同时也有施工单位和预拌混凝土企业间的配合不畅导致的混凝土运输车在施工场地上停留时间较长,以上因素导致很多预拌混凝土在出厂后2小时以上才能泵送施工,因此也造成很多混凝土的工作性能达不到施工要求而形成供需双方矛盾频出,也导致了很多现场加水现象的出现。为了避免上述预拌混凝土因中途停留时间过长导致的工作性能不满足要求的问题,本期特别策划将就该问题进行探讨,如何才能实现出厂长时间(2小时及以上)的混凝土工作性满足要求? With the acceleration of the national urbanization process, the transportation distance of ready-mixed concrete is expanding. The congestion effect in large and medium-sized cities prolongs the transportation time of ready-mixed concrete and the poor cooperation among the contractors and ready-mixed concrete enterprises Of the concrete trucks stay longer on the construction site, the above factors lead to a lot of ready-mixed concrete at the factory for more than 2 hours to pump construction, it also caused a lot of concrete performance does not meet the construction requirements and the formation of contradiction between supply and demand frequency Out, but also led to the emergence of many on-site water phenomenon. In order to avoid the problem that the workability of the above ready-mixed concrete due to too long stay time does not meet the requirements, this special issue will be explored on this issue and how to meet the concrete working conditions of leaving factory for a long time (2 hours and above) Claim?