Post-tensioning pre-stress duct grout material for low temperature condition

Abstract

The present invention discloses a post-tensioning pre-stress duct grout material for a low temperature condition, and belongs to the technical field of building materials. The post-tensioning pre-stress duct grout material comprises a coagulation accelerating component, an anti-freezing component, a polycarboxylic acid water reducing agent, an expanding agent, an antifoaming agent, polyacrylamide, a plasticizer and a mineral admixture, wherein the anti-freezing component is a mixture obtained by compounding a nitrite and a sulfate according to a weight ratio of 0.5-2.0:0.5-1.0. The post-tensioning pre-stress duct grout material has characteristics of significant low-temperature resistance effect, controllable setting time, appropriate initial setting time, appropriate final setting time, high compressive strength, high bending strength, zero free bleeding rate, stable performance, and easy and convenient use, and can be widely used in highway bridge and culvert construction.

Description

technical field [0001] The invention belongs to the technical field of building materials, and relates to a post-tensioned prestressed tunnel press slurry, in particular to a low-temperature post-tensioned prestressed tunnel press slurry. Background technique [0002] In recent years, the construction of highways and bridges in my country has developed rapidly, and the design and construction of long-span prestressed concrete bridges have become a popular trend. The advantages of effectively avoiding concrete cracking, convenient use of curved reinforcement, and no need for huge tensioning pedestals have been widely used in engineering. [0003] Grouting in the channel is to inject the grout into the reserved prestressed concrete pipe, so that the grout can fully wrap the prestressed tendons, and its function is to protect the prestressed steel bars from corrosion and make them well combined with the concrete, so as to ensure the effective prestressing. Transfer, so that pre...

AI Technical Summary

Problems solved by technology

During construction, cement, water, water reducing agent, expansion agent, thickener, etc. are used for on-site preparation, which has strict requirements on the construction environment, and it is difficult to adapt to the winter construction conditions in the north

In addition, the composition of grouting materials is relatively complex, and there are many powder components added on site, which requires high measurement accuracy, and the quality of construction personnel is uneven, lacking effective quality management methods, and the performance of grouting materials cannot be guaranteed. There are usually poor compatibility of various additives, poor adaptability of cement and water reducer, etc., resulting in the following serious problems in post-tensioned prestressed tunnel grouting: 1) The construction cannot be carried out when the temperature is lower than 5°C; 2) The quality stability of the grout and Poor fluidity, rapid loss of fluidity and poor volume stability; 3) The freshly mixed slurry has a high bleeding rate and is easy to segregate and stratify, making it difficult to form a full state in the channel; 4) After hardening, the slurry is not dense and has many voids

Images