Low and ultra-low cement castables

Mixing is divided into mechanical mixing and manual mixing. At present, forced or mortar mixers are used in the industry to mix materials, and manual mixing is not used Equipment and tools: forced or mortar mixers, buckets, scales, vibrators, tool shovels, trolleys, etc.

The construction water consumption is based on the water consumption indicated in the quality inspection sheet of the batch of products, and is strictly implemented in accordance with the standards to achieve accurate measurement.

Mixing: Mix dry first and then wet. Put the bulk material into the mixer and dry for 1-3 minutes in the order of the big bag first and then the smallbag to make it evenly mixed. The weight of each mixing is determined according to the machinery and construction volume; according to theweight of the material, the water required for each mixing is accurately weighed according to the specified water consumption, added to theuniformly mixed dry material, and fully stirred. The time is not less than 3min, so that it has suitable fluidity, and then the material can bedischarged for pouring.

Before the pouring material is constructed, it is necessary to check whether the anchors are firmly welded, and heat-resistant nails should beused for parts above 500C. The surface of the anchor should be painted with 0. 5-1mm thick paint or wrapped with plastic tape to buffer theexpansion force after heating and remove the debris in the mold.

The newly mixed castable should be poured quickly, generally within 20min. Pour the mixed castable into the mold, and insert the vibrator intothe vibrator in time, and the vibrator should be uniform. When the surface of the castable is slurried, bubbles are discharged. When the surface isslurried, the vibrating rod is moved, and the moving speed is 1-2m/min. When the vibrating rod is pulled out, the speed is slow.

Before solidification is completed after pouring, the site temperature must be kept above 10C(10-30.C). If the site temperature is lower than0'C, corresponding heating and heat preservation measures must be taken, otherwise it will cause retardation and lead to product performancedegradation.

The main tools used are polyethylene plastic film, straw bags, etc. Ambient temperature requirements and control: The curing temperature of the casting body is preferably between 15-35C If the temperature exceeds this temperature range, corresponding heating or cooling measuresshould be taken, otherwise the performance of the product will be reduced.

After the castable is hardened, it is necessary to immediately cover the surface of the construction body with polyethylene plastic film, and thercover it with a wet straw bag to prevent water evaporation and promote cement activation After hardening, it is forbidden to beat and vibratewithin one day. According to the hardening situation, it can be demolded after 24-30 hours of hardening.

After demoulding, it should be maintained for two days as needed, and polyethylene plastic film and wet straw bags should be added duringmaintenance. After three days of curing, remove the plastic film and straw bag. Allow the hardened body to dry naturally in the air for a daybefore baking.

Baking is the last key link in the use of castables. Since the casting body is relatively dense, it is absolutely forbidden to heat up too fast duringbaking, otherwise it will cause a cracking accident.