1, volume: cementing material for the general volume of 5-10%. The method of mixing silica fume into admixture with additive,
(1), mixed: no change in the water under the premise of 1 silica fume can be replaced by cement were 3-5 (weight) and keep the same strength of concrete and other concrete to improve performance.
(2), mixed: the same amount of cement, mixing silica fume significantly increase the strength of concrete and other properties. The introduction of silica fume concrete when there is a certain loss of slump. This need to be the pilot Mix attention.
Silica fume and water reducer to be used in conjunction with the proposed resumption of fly ash and ground slag in order to improve the construction of.
Using silica fume concrete preparation, and general-to-weight ratio of cementing material:
(A) high-performance concrete 5-10%;
(B) 5-hydraulic concrete 10%
(C) 5-shotcrete 10%;
(D) to help pump agent :2-3%;
(E) of the industry to Wear Ping 6-8%;
(F) polymer mortar, mortar insulation 10-15%
(G) of monolithic castables 6-8%. Please use the former according to actual needs through the selection of reasonable test, the economic content.
2 ﹑ adding:
Silica fume concrete pouring and laboratories should be expected to make a mix of construction. Mix in strict accordance with the construction. In the silica fume concrete mixing of the silica fume should be in the aggregate is expected to vote immediately after accession to the mixer. There are two ways to join:
(1) of the aggregate investment, and then into silica fume, cement mixed with dry, add water and other admixtures.
(2) +75% of the aggregate into rough water + +50% silica fume fine aggregate, mixing 15-30 seconds, and then into concrete admixture + +50% +25% of the aggregate fine of water, stirring to evenly. Stir longer than ordinary concrete extension of the 20-25% or 50-60 seconds. Should not have to join the mixing of the silica fume concrete.
3, construction method:
Silica fume concrete and ordinary concrete construction method there is no significant difference, but the construction of a good organization and vibration to dense necessary. Silica fume concrete early strong performance ahead of time to make final setting, the surface should be a major contributing factor in the increase in attention; at the same time adding silica fume concrete will increase the viscosity and substantially reduce the bleeding so slightly difficult to clean surface.
4, Construction Safety:
Silica fume concrete construction safety should be strictly in accordance with concrete projects related to national construction norms to operate, but less silica fume, high-altitude Paosa material is strictly prohibited, to prevent the silica fume emissions.
