What are the national standards for Refractory castable cement construction

Many Refractory castable cement constructions can be inspected and tested according to the current national standard of "Test Methods for Thermal Expansion of Refractory Materials" GB/T7320. The casting of Refractory castable cement lining should meet the following requirements:

1. The construction site should be cleaned up first.

2. When refractory castable cement is in contact with refractory bricks or insulation products, water absorption measures should be taken to isolate it. Foam board and plastic cloth can be used for isolation during construction, and it should be removed after construction.

The surface of the template used for pouring the furnace lining should be smooth, have sufficient rigidity and strength, and have a simple structure. The support and removal of the template should meet the following requirements:

1. The support is firmly assembled and disassembled to facilitate no leakage at the joints. The wooden slats reserved for expansion joints should be fixed firmly to avoid displacement during vibration.

2. For refractory castable cement with strong corrosiveness or cohesiveness, an isolation layer should be set in the formwork to take anti-adhesion measures. The thickness direction dimension is accurate and the allowable deviation is +2～-4mm. When the strength of cast Refractory castable cement does not reach 1.2MPa, no formwork should be installed on it.

3.The height of the horizontally layered segmented or block-spaced support formwork should be determined according to the construction site ambient temperature, pouring speed and refractory castable cement setting time and other factors. Generally, it should not exceed 1.5m.

4. The load-bearing template should be removed when the Refractory castable cement reaches 70% of its strength. Refractory castable cement should be baked to the specified temperature before removing the mold.

5. The expansion joint gap size and distribution position and structure of the integral casting furnace lining should meet the design regulations, and fill materials according to the design regulations. When the design does not specify the expansion joint gap size, the average value of the expansion joint per meter of furnace lining. Lightweight Refractory castable cement surface expansion line can be set during pouring or cut after pouring. When the thickness of the lining is greater than 75mm, the width of the expansion line should be 1～3mm and the depth should be 1/3～1/4 of the thickness of the lining. It should be 0.8～1m and set in the shape of a well.

6. When the thickness of the Refractory castable cement furnace lining is less than 50mm, the manual coating method can also be used for continuous pouring and manual tamping. After pouring, the surface of the furnace lining should be smooth and compact without calendering.

Lightweight Refractory castable cement The thickness of the furnace lining is 200mm, and the part where the inclination of the furnace lining surface is less than 60 can be poured by hand. The cloth should be evenly distributed. Continuous pouring is made with a rubber hammer or a wooden hammer. The vibrator vibrating and compacting furnace lining surface should be flat and compact without loose particles.