Blending amount
Generally 5-10% af mængden af cementholdige materialer.
The mixing method of silica fume is divided into internal mixing og external mixing.
- Intern blanding: under forudsætning af den samme mængde vand, 1 part of silica fume can replace 3-5 dele af cement (vægt) and keep the compressive strength of concrete unchanged while improving other properties of concrete.
- External mixing: mængden af cement forbliver uændret, and the addition of silica fume significantly improves the strength of concrete and other properties. Concrete mixed with silica fume when there is a certain slump loss. Dette punkt skal bemærkes i forholdstesten.
Silica fume must be used in conjunction with water reducing agents, it is recommended to compound fly ash and finely ground slag to improve its constructability.
When formulating concrete with silica fume, the general weight ratio with cementitious materials is:
- Høj ydeevne beton: 5-10%.
- hydraulisk beton: 5-10%
- Shotcrete: 5-10%.
- Pumpehjælp: 2-3%.
- slidstærkt industrigulv: 6-8%.
- polymermørtel, isoleringsmørtel: 10-15%.
- Ubegrænsede ildfaste støbegods: 6-8%. Før brug, please select the reasonable and economic mixing amount through experiment according to the actual needs.
Mixing method.
Silica damp beton and castables should be made by the test room. Følg nøje konstruktionsforholdet. Silica fume should be added to the mixer immediately after the aggregates are fed. Der er to procedurer for tilføjelse.
- Into the aggregate, followed by silica fume, cement tørblanding, and then add water and other admixtures.
- Kom groft tilslag i + 75% vand + Silica røg + 50% fint tilslag, bland til 15-30 sekunder, kom derefter i cement + blanding + 50% fint tilslag + 25% vand, bland indtil ensartet. Blandetiden er 20-25% eller 50-60 sekunder længere end almindelig beton. Tilsæt aldrig silicapulver i den allerede blandede beton.
Construction method
There is no significant difference between the construction method of silica fume concrete and ordinary concrete, but it is necessary to organize and vibrate densely during construction well. The early strength of silica fume concrete will make the final setting time earlier, som man skal være opmærksom på ved pudsning; på samme tid, the addition of silica fume will improve the viscosity of concrete and significantly reduce water secretion, gør pudsning lidt vanskelig.
Construction safety
Silica fume concrete construction safety should be strictly in accordance with the relevant national construction specifications for concrete projects, but because silica fume is light, it is strictly prohibited to throw the material from a height to prevent silica fume from flying.
