# The Preparation of Active Support-Based Sealing Material and Sealing Effect Analysis
## 2 Sealing Material Preparation Based on Orthogonal Test
### Raw Materials and Test Method
#### 2.2.2 Test Method  
The test contents include the material mobility, bleeding rate, initial setting time, expansion rate and compressive strength. The test scheme is shown in Figure 3.  
Fluidity  
Before the test, prepare a smooth sheet with a side length of 50 cm, a truncated cone mold and a steel rule. Wipe the smooth sheet and the truncated cone mold with a wet rag, then pour the prepared slurry into a slightly wet truncated cone mold and smooth the slurry with a steel rule. After smoothing, quickly lift the truncated cone mold. The maximum diameter of the two directions perpendicular to each other of the slurry flow expansion is measured with a steel ruler, and the average value is taken as the fluidity of the slurry. For the bleeding rate of the material, refer to JC/T2153-2012 Test Method for Cement Bleeding Water. The test steps are as follows: weigh the mass \(M_{1}\) of the measuring cylinder, pour the prepared slurry into the measuring cylinder, weigh the total mass \(M_{2}\) of the measuring cylinder and the slurry, and then wait for 30 min for each interval. The volume of bleeding is observed for 5 min until the bleeding disappears, and the water droplets are poured into a 25 mL measuring cylinder with a glue head dropper to read the mass \(W_{\text{b}}\) of the water. The formula for calculating the bleeding rate of the material is as follows:  
\[B_{w}=\frac{W_{b}}{(M_{2}-M_{1})\omega} \tag{1}\]  
where \(\omega\) denotes the moisture content of the slurry. The test instrument used for the initial setting time of the material is a Vicar instrument. The test steps are as follows: place a small glass plate at the bottom of the test mold, record the time of initial mixing slurry, and then pour the prepared good slurry into the test mold. After a period of time, the test begins. When the scale number is observed to be about 4 mm, record this moment as the initial setting time of the material. Figure 2: Raw materials for test: (**a**) Portland cement; (**b**) quicklime; (**c**) accelerating agent; (**d**) expanding agent; (**e**) fly ash. The test method used for the expansion rate of the sealing material is the standard JC/T 313-2009 Test Method for the expansion rate of expansion cement. The test mold is 25 mm \(\times\) 25 mm \(\times\) 280 mm, and the length change value of the test block is measured by the length ratio instrument. The prepared test block was put into a standard curing box for 28 days. The size of the sample was a cube with a side length of 70.7 mm. The SNAS uniaxial testing machine was used to test the uniaxial compressive strength of the material. Test scheme. The Design of Orthogonal Test  
In the orthogonal test, the water/cement ratio, the content of quicklime, fly ash, accelerating agent, and expanding agent were set as influence factors. With the comprehensive consideration of the test scheme and actual needs, this study selected four levels of these five influence factors to conduct the orthogonal test. In total, 16 groups of tests were conducted. The influence factors and their respective levels are shown in Table 1. The content of each factor is denoted by their ratio with Portland cement. Table 2 shows the results of the sixteen groups of orthogonal tests. As can be seen, the fluidity of every water/cement ratio is greater than 250 mm. According to the relevant literature, the grouping material fluidity can meet the pumping requirements when it is greater than 140 mm [31]. Therefore, the fluidity of the materials is not considered in the comprehensive analysis of the orthogonal test.