The low negative temperature pipeline grouting material is a new product developed by the China Academy of Railway Sciences based on the actual construction of the Harbin Dalian Railway and the Ministry of Railways' Science and Technology Research and Development Plan project "Key Technology Research for Winter Construction of Railway Passenger Dedicated Line Bridges in Cold Regions".
1. Product Introduction
The low negative temperature pipeline grouting material is a new product developed by the China Academy of Railway Sciences based on the actual construction of the Harbin Dalian Railway and the Ministry of Railways' Science and Technology Research and Development Plan project "Key Technology Research for Winter Construction of Railway Passenger Dedicated Line Bridges in Cold Regions". This product has good fluidity, low bleeding rate, rapid strength development, anti steel corrosion function, and micro expansion performance, and is suitable for post tensioned prestressed pipeline grouting construction under low negative temperature conditions. Refer to the standards TB/T3192-2008 and GB/T50448-2008.
2. Scope of application
(1) Pipeline grouting construction carried out under low temperature conditions to improve construction speed.
(2) Pipeline grouting construction at ambient temperatures above -10 ℃ without maintenance conditions.
(3) Pipeline grouting construction under appropriate maintenance conditions at ambient temperatures above -20 ℃.
3. Instructions for use
(1) Try to choose the hottest time of the day for grouting and verify the temperature situation in the prestressed pipeline. Detailed construction measures should be developed based on environmental conditions and material characteristics during construction.
(2) Directly mix with water on site, and do not use it in combination with ordinary silicon cement. The water to material ratio should not exceed 0.32, and should be thoroughly mixed evenly. The amount of water used should be minimized while meeting the consistency of the cement slurry.
(3) Groundwater is used for mixing, and the specific water temperature is determined based on the operable time and the normal strength development of the slurry under construction environmental conditions.
(4) Before grouting, a warm air blower is used to preheat the prestressed pipeline with hot air to improve the safety and reliability of the structure.
(5) Reasonably calculate the amount of materials used each time based on the construction speed, and complete the construction within the specified time. Clean equipment and tools promptly after grouting is completed.
(6) When the temperature is low, appropriate maintenance measures should be taken, such as insulation treatment for mixing and grouting equipment, and insulation treatment for both ends of the bridge. The ambient temperature should be controlled above -10 ℃ by setting up a warm shed. Before grouting, the prestressed pipeline should be preheated by blowing hot air through a warm air blower to ensure that the temperature inside the pipeline is above -10 ℃.
(7) After grouting, the ambient temperature of the beam should be kept above -10 ℃ for at least 12 hours.
