Anti-freezing cement asphalt mortar and preparation method thereof

Abstract

The invention discloses an anti-freezing cement asphalt mortar and a preparation method thereof. The cement asphalt mortar comprises emulsified asphalt, cement, fine sand, an expansive agent, an aluminite powder and water. A formula of the emulsified asphalt comprises asphalt, an anionic emulsifier, a cationic emulsifier, a thickener, a stabilizer, a water reducing agent, a defoaming agent, alcohol and water. The cement asphalt mortar provided by the invention employs special emulsified asphalt; and when the cement asphalt mortar is mixed with dry material such as cement and sand, the water reducing agent and the defoaming agent are easily dispersed to fully contact with the dry material, thus realizing obvious water reducing effect, effectively avoiding bleeding phenomenon after pouring of CA mortar, and improving workability of the emulsified asphalt with cement and fine sand; and synergistic effect of alcohol improves anti-freezing performance of the CA mortar, effectively eliminates large bubbles, and realizes dense and uniform texture after forming of the CA mortar. The cement asphalt mortar provided by the invention is particularly suitable for perfusion under track plate as a buffer layer in construction of high-speed railway.

Description

technical field [0001] The invention relates to a frost-resistant cement-asphalt mortar and a preparation method thereof, in particular to a cement-asphalt mortar (CA mortar for short) poured under a slab-type ballastless track slab for building high-speed railways and a preparation method thereof. Background technique [0002] With the improvement of the level of railway construction and the requirements for railway transport capacity, it is necessary to build high-speed railways and intercity light rails. In order to improve the stability of trains running at high speed and reduce the noise caused by vibrations when trains are running, slab ballastless track technology is adopted. The slab ballastless track technology is to lay two tracks on a reinforced concrete slab (called track slab), and a 3-5cm thick shock-absorbing layer needs to be laid under the track slab. The shock-absorbing layer is made of emulsified asphalt, cement, Fine sand and other mineral materials form ...

AI Technical Summary

Problems solved by technology

The process of preparing mortar is carried out in a mixer truck, which is an intermittent operation. Due to the small amount of defoamer and water reducer, it is difficult to control the measurement accurately, and even if it is stirred quickly, the distribution of the two in the mortar It is also difficult to be uniform. Once the measurement is wrong or the distribution is uneven, it will affect the properties of the mortar. The main performance is that the defoaming is not complete. When the mortar is poured, more air bubbles will be accumulated under the four corners of the track plate. Insufficient strength of the corners

In addition, in order to make the high-iron emulsified asphalt mixed with a large amount of cement and fine sand not to be demulsified during high-speed stirring, and to have a certain strength against mechanical damage, generally when producing high-iron emulsified asphalt, the amount of surfactant will be If the emulsified asphalt is very large, it is easy to produce a large amount of foam during the production and loading of high-speed rail emulsified asphalt, occupying a large space in the product tank. If the operation is not done properly, the emulsified asphalt foam will easily emerge from the tank mouth, which will cause inconvenience to production and transportation.

In addition, if the foam of the emulsified asphalt is too much, a thick skin will be formed after the foam disappears. This skin is formed by linking the asphalt components on the foam after the foam disappears, and it can no longer be emulsified even if it is stirred. , so it will affect the properties of emulsified asphalt, especially the index of remaining amount on the sieve, and even easily lead to the demulsification of emulsified asphalt

In addition, adding defoamer and water reducing agent at the construction site is cumbersome, which affects the construction progress and adds trouble to the structural design of the mixer truck