To make silica fume concrete, the concrete type and use shall be determined first. The amount of silica fume added to different types of concrete is different. Generally speaking, the content of silica fume is 5-10% of the amount of cementing material.
When making silica fume concrete, generally speaking, the ratio of silica fume to cement is:
(1)High-performance concrete: 5-10%;
(2) Hydraulic concrete: 5-10%
(3) Shotcrete: 5-10%;
(4) Pumping aid: 2-3%;
(5) Wear-resistant industrial floor: 6-8%;
(6) Polymer mortar and thermal insulation mortar: 10-15%,
(7)Unshaped refractory castable: 6-8%. Please select a reasonable and economical dosage through experiments according to actual needs before use.
Making silica fume concrete
first, the agglomerations that make up the densified silica fume must be broken down. second, the silica fume must be distributed uniformly throughout the concrete.
- place 75% of water in the mixer
- Add coarse aggregate
- Add silica fume slowly into the revolving mixer
- Mix 1-1/2 minutes
- Add cement and fly ash or slag cement, if being used, slowly into the revolving mixer
- Mix 1-1/2 minutes
- Add fine aggregate
- Wash-in all ingredients using the remaining 25% of water
- Mix 3 minutes
- Rest 2 minutes
- Mix 2 minutes
Silica fume must be used in combination with a water reducing agent. It is recommended to mix fly ash and ground slag to improve its workability.
silica fume must always be added with the coarse aggregate and some of the water. batching silica fume alone or first can result in head packing or balling in the mixer.mix silica fume, coarse aggregates, and water for 1½minutes
