搜索历史清除全部记录
- All
- Product Management
- News
- Introduction
- Enterprise outlets
- FAQ
- Enterprise Video
- Enterprise Atlas
Comprehensive Control Strategy for Preventing Concrete Segregation During Pumping with Truck-Mounted Pumps
Release time:
2026-05-08
Source:
Author:
Summary:
Concrete segregation refers to the separation of its constituent components—coarse aggregate, fine aggregate, and cement paste—under the action of pumping forces or self-weight, thereby compromising homogeneity. During high-pressure, long-distance pumping with truck-mounted concrete pumps, segregation significantly increases the risk of pipe blockage and severely affects the strength and durability of the placed concrete. Preventing segregation is a systematic undertaking that spans the entire process chain, from mix design and production–transportation to pumping operations and on-site management.
I. Optimizing Mix Proportion Design to Lay the Foundation for Anti-Segregation
The intrinsic ability of concrete to resist segregation is primarily determined by its material composition.
1. Scientific aggregate gradation: Continuous and well-graded aggregate is essential. The fine aggregate (sand) should be proportioned appropriately to fill the voids between the coarse aggregates, thereby forming a dense skeletal structure. If the sand ratio is too low, the paste volume will be insufficient to coat and lubricate the coarse aggregates, leading to segregation during pumping; if the sand ratio is too high, the water demand increases, compromising concrete stability. At the same time, the maximum nominal size of the coarse aggregate must be strictly controlled, generally not exceeding one-third of the diameter of the delivery pipe.
2. Adequate cementitious materials and high-quality mineral admixtures: Sufficient cement paste is essential for coating the aggregates and providing lubrication. Mineral admixtures such as fly ash and ground granulated blast-furnace slag may be added in appropriate amounts. These fine-particle materials effectively enhance the cohesion and water retention of the paste, resulting in more stable concrete under pumping pressure and reducing the likelihood of bleeding and segregation.
3. Precise application of high-efficiency admixtures: High-performance polycarboxylate superplasticizers can significantly reduce water demand at very low dosages, thereby maintaining a low water-to-binder ratio while ensuring the required workability—this is a key technical approach for producing highly stable, segregation-resistant concrete. In some cases, viscosity-modifying agents or slump-retaining agents may be used in combination to further enhance the homogeneity of the fresh mix during prolonged pumping.
II. Standardize the production and transportation processes to maintain the stability of the mix.
The period between factory shipment and pumping is critical for maintaining the concrete’s consistency.
1. Mixing and Charging Control: Ensure adequate mixing time to achieve uniform blending of all components. During charging, the mixer truck’s drum should maintain its normal rotational speed to prevent sedimentation and segregation when the mixture is stationary.
2. Management of the Transportation Process: During transit, the mixing drum must maintain a slow rotational speed. The transportation distance and duration should be carefully planned to prevent excessive waiting time due to traffic delays, which could result in significant slump loss or premature setting and segregation of the concrete.
III. Precision Pumping Operations and On-Site Management
This is the final and most direct line of defense against segregation.
1. Compliance inspection prior to pumping:
Concrete Acceptance: Prior to pumping, the slump and workability must be tested on site. Visual inspection shall verify that the concrete mix is uniform and free from bleeding or exposed aggregates. Any concrete that fails to meet the specified requirements shall be firmly rejected and must not be pumped.
Pipeline Wetting and Sealing: Prior to pumping, lubricate the pipeline with cement mortar or cement slurry having the same mix proportion as the concrete. This not only reduces frictional resistance but, more importantly, fills the gaps between the pipe walls with the slurry, forming a lubricating layer that prevents the paste in the subsequent concrete from being rapidly absorbed and causing aggregate segregation.
2. Precise control of the pumping process:
Speed and Pressure Management: Adhere to the “slow start, steady delivery, gradual stop” principle. Initiate pumping at a low speed, and once the system has stabilized, increase to the normal pumping rate. Avoid abrupt changes in pumping speed or arbitrary stops, as sudden pressure fluctuations and periods of stagnation can easily lead to stratification and segregation of the concrete within the pipeline. When a temporary pause is necessary, perform intermittent forward-and-reverse pump strokes every few minutes to prevent the concrete from settling and segregating due to prolonged standstill.
Pipeline layout and maintenance: Minimize the number of bends and use large-radius bends. Ensure tight, leak-proof pipe connections to prevent grout leakage. Once grout leakage occurs, the immediate loss of concrete slurry at that location will lead to aggregate blockage.
3. Handling Special Cases:
For ultra-high-rise or ultra-long-distance pumping, hydraulic shut-off valves should be installed at intermediate points along the pipeline to prevent concrete at elevated or remote locations from backflowing and segregating due to gravity or pressure rebound when pumping is halted.
During periods of high summer temperatures, conveyance pipelines should be shaded and cooled to prevent rapid evaporation of concrete moisture, which can lead to surface hardening and increased flow resistance.
Summary
Preventing concrete segregation during truck-mounted pumping is a systematic endeavor that requires the seamless integration of stable mix design and meticulous operational practices. It begins at the material source, where a mix with excellent cohesiveness and high water retention must be formulated; during transportation, the mix must be kept uniformly homogeneous; and finally, through standardized pre-pump inspections, smooth pumping operations, and scientifically sound pipeline management, the “smooth journey” of concrete through the delivery pipeline can be reliably ensured. Only by embedding both technical expertise and rigorous management throughout every stage of the process can segregation risks be effectively mitigated, pumping operations conducted efficiently and smoothly, and the ultimate quality of the constructed structure guaranteed.
RELATED INFORMATION
Contact Us
Changsha Base:Hunan Zenxon Heavy Industry Technology Co., Ltd.
Address: Jinrong Tongxin International Industrial Park, Changsha High-tech Zone
Loudi Base:Hunan Haoda Heavy Industry Technology Co., Ltd.
Address: Loudi Avenue, Loudi High-tech Industrial Development Zone, Lianyuan City, Loudi City, Hunan Province
Telephone:400-186-0868
E-mail:3804246750@qq.com
E-mail:19967177733@163.com
0
Consult now
WeChat Public Number
TikTok